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United States Patent Application
20060069925
Kind Code
A1
Nakai; Shinichi ; et al.
March 30, 2006
Content processing device, content accumulation medium, content processing method and content processing program
Abstract
With respect to encrypted content 104 stored in content storage medium 102, by storing information with a small data amount related to the encrypted content 104 in content storage medium 102 in association with the encrypted content 104, it is possible to distinguish between encrypted content 104 based on the related information without decoding the encrypted content 104 with a large data amount. It is thereby possible to more readily distinguish between a plurality of pieces of content stored in the content storage medium.
Inventors:
Nakai; Shinichi
(Kanagawa, JP)
, Noguchi; Naohiko
(Kanagawa, JP
)
, Matsui; Shinichi
(Kyogo, JP
)
, Nanba; Takaaki
(Aichi, JP
)
, Inoue; Ryuji
(Osaka, JP
)
Correspondence Name and Address:
112 South West Street
NATH & ASSOCIATES
Alexandria
VA
22314
US
Series Code:
509125
Claims
1-46. (canceled)
47. A content processing apparatus comprising: a first storage section that stores therein an identifier unique to the content processing apparatus and identification data; an encrypting section that encrypts content using the identification data using the identifier; and an output section that stores the encrypted content and the encrypted identification data in content storage medium in association with each other.
48. The content processing apparatus according to claim 47, further comprising: an authentication section that determines whether access is allowed to a first area of the content storage medium, the content storage medium having the first area and a second area, wherein the output section stores the identification data encrypted in the first area, and stores the content encrypted in the second area.
49. The content processing apparatus according to claim 47, further comprising: a second storage section that stores therein a title of the content, in association with the identification data.
50. A content processing apparatus comprising: a first storage section that stores therein an identifier unique to the content processing apparatus; an encrypting section that encrypts content using the identification data using the identifier; and an output section that stores the encrypted content in a directory of a content storage medium, a name of the directory based on the identifier.
51. The content processing apparatus according to claim 50, wherein the first storage section stores a plurality of identifiers, and the identifier used in encrypting is different from the identifier used as the name of the directory of the content storage medium.
52. The content processing apparatus according to claim 50, wherein the name of the directory of the content storage medium is obtained by encrypting the identifier.
53. The content processing apparatus according to claim 50, wherein the output section stores information related to the encrypted content and the encrypted content in the same directory in the content storage medium.
54. A content processing apparatus comprising: a first storage section that stores therein an identifier unique to the content processing apparatus; an authentication section that determines whether access is allowed to a first area of the content storage medium, the content storage medium having the first area and a second area; an encrypting section that encrypts content using the identifier; and an output section that stores the identifier in the first area and stores the encrypted content in the second area, in the content storage medium.
55. The content processing apparatus according to claim 54, wherein the output section stores at least one of: the encrypted content and link information that associates the identifier with the encrypted content in the same directory in the content storage medium; and the encrypted content and the identifier in the content storage medium so that information indicative of a storage location of the encrypted content in the second storage area agrees with information indicative of a storage location of the identifier in the first area.
56. A content processing apparatus comprising: a first storage section that stores therein an identifier unique to the content processing apparatus; a second storage section that stores therein information which is different from the identifier and is used to determine whether encrypted content to be stored in a content storage medium can be decoded in the content processing apparatus; an encrypting section that encrypts content using the identifier; and an output section that stores the encrypted content and the information in the content storage medium.
57. The content processing apparatus according to claim 56, further comprising: an authentication section that determines whether access is allowed to a first area of the content storage medium, the content storage medium having the first area and a second area, wherein the output section stores the information to determine the encrypted content in the first area, and stores the encrypted content in the second area in association with the information.
58. The content processing apparatus according to claim 56, wherein the information used to determine the encrypted content is inputted information set or information set by the content processing apparatus.
59. A content processing apparatus comprising: a first storage section that stores therein an identifier unique to the content processing apparatus; a second storage section that stores therein a directory name of a content storage medium used to store encrypted content; an encrypting section that encrypts content using the identifier; and an output section that stores the encrypted content in a directory in the content storage medium with the same directory name as the directory name stored in the second storage section.
60-66. (canceled)
67. A content processing apparatus comprising: an input section that reads out encrypted content from a content storage medium, and encrypted first identification data from the content storage medium; a first storage section that stores therein second identification data and an identifier unique to the content processing apparatus; a decoding section that decodes the encrypted first identification data using the identifier; and a comparing section that compares the decoded first identification data with the second identification data stored in the first storage section, wherein when the decoded first identification data agrees with the second identification data, the decoding section decodes the encrypted content using the identifier.
68. The content processing apparatus according to claim 67, further comprising: an authentication section that determines whether access is allowed to a first area of the content storage medium, wherein which the encrypted first identification data is stored in the first area and the encrypted content is stored in a second area of the content storage medium.
69. The content processing apparatus according to claim 67, further comprising: a second storage section that stores therein a title of the content corresponding to the second identification data; and a display section that displays the title stored in the second storage section when the comparison of the comparing section indicates that the first identification data agrees with the second identification data stored in the first storage section.
70. A content processing apparatus comprising: an input section that reads out encrypted content from a content storage medium and a name of a directory from the content storage medium storing the content; a first storage section that stores therein an identifier unique to the content processing apparatus; a comparing section that compares the name of the directory read from the content storage medium with the identifier; and a decoding section that decodes the encrypted content using the identifier, when the name of the directory agrees with the identifier.
71. The content processing apparatus according to claim 70, wherein the first storage section stores a plurality of identifiers, and the identifier used to compare with the name of the directory read from the content storage medium is different from the identifier stored in the first storage section and used for decoding the encrypted content.
72. The content processing apparatus according to claim 70, wherein the name of the directory of the content storage medium is encrypted, and the comparing section compares the name of the directory decoded in the decoding section with the identifier.
73. The content processing apparatus according to claim 70, further comprising a display section and wherein when the name of the directory agrees with the identifier in the comparing section, the display section displays information related to the encrypted content stored in the directory containing the encrypted content in the content storage medium.
74. A content processing apparatus comprising: an authentication section that determines whether access is allowed to a first area of a content storage medium the content storage medium having the first area and a second area; an input section that reads out a first identifier from the first area in the content storage medium, and encrypted content, associated with the first identifier, from the second area in the content storage medium; a first storage section that stores therein a second identifier unique to the content processing apparatus; a comparing section that compares the first identifier with the second identifier; and a decoding section that decodes the encrypted content using the second identifier when the first identifier agrees with the second identifier.
75. The content processing apparatus according to claim 74, wherein the input section reads out at least one of: the encrypted content from the content storage medium using link information stored in the same directory as that of the encrypted content; and the encrypted content indicating a same position information in the second area as information indicating a storage location of the identifier in the first area.
76. A content processing apparatus comprising: an input section that reads out encrypted content from a content storage medium, and first information to determine whether the encrypted content in the content storage medium can be decoded in the content processing apparatus; a first storage section that stores therein an identifier unique to the content processing apparatus; a second storage section that stores therein second information that is different from the identifier and used to determine whether the encrypted content can be decoded in the content processing apparatus; a comparing section that compares the first information with the second information; and a decoding section that decodes the encrypted content using the identifier when the first information agrees with the second information.
77. The content processing apparatus according to claim 76, further comprising: an authentication section that determines whether access is allowed to the first storage section of the content storage medium in which the first information used to determine the encrypted content is stored in the first storage section and the encrypted content is stored in the second storage section.
78. The content processing apparatus according to claim 76, wherein the second information used to determine the encrypted content is inputted information or information set by the content processing apparatus.
79. A content processing apparatus comprising: an input section that reads out encrypted content and a name of a first directory from a content storage medium in which the encrypted content is stored in the first directory; a first storage section that stores therein an identifier unique to the content processing apparatus; a second storage section that stores therein a second directory name of the content storage medium in which the encrypted content is stored; a comparing section that compares a name of the first directory with the second directory name; and a decoding section that decodes the encrypted content using the identifier when the name of the first directory agrees with the second directory name.
80-86. (canceled)
Description
TECHNICAL FIELD
[0001] The present invention relates to a content processing apparatus, content storage medium, content processing method and content processing program to store content in the content storage medium to use.
BACKGROUND ART
[0002] Conventionally, there are terminal apparatuses such as cellular telephones that download various kinds of content from content providers to use in the terminal apparatuses.
[0003] A terminal apparatus allowed to download content stores the downloaded content in a detachable content storage medium such as a memory card, and thereby is capable of providing a plurality of pieces of content to its user without increasing the capacity of the internal memory. It is thus possible to avoid increases in size of the terminal apparatus and ensure portability.
[0004] In the case of storing the content in the content storage medium, the terminal apparatus encrypts the content by a predetermined encryption method to store. It is thereby limited using the content stored in the content storage medium in another use environment.
[0005] Further, the content storage medium allows not only a single terminal apparatus but also a plurality of terminal apparatuses to store encrypted content therein. It is thus possible for a user to store in a single memory card pieces of content that are downloaded in a plurality of terminal apparatuses in possession of the user. Thus, cases occur where pieces of content stored by a plurality of different terminal apparatuses coexist in a single content storage medium.
[0006] Content has a different target terminal apparatus capable of using the content corresponding to the type and structure of the terminal apparatus.
[0007] Accordingly, when a content storage medium is inserted into a terminal apparatus and content is read from the content storage medium, the terminal apparatus reads out the content one by one from the inserted content storage medium, decodes each content completely, and then, is first allowed to judge whether or not the content is available.
[0008] In this way, in the conventional terminal apparatuses, as the operation for finding content available in a terminal apparatus used at the moment from among a plurality of pieces of content stored in the content storage medium, complicated operation is required such that each content is read from the inserted content storage medium and judgment on whether the content is available or not is made after decoding the read content sequentially, and there arises a problem that the time required for the operation increases.
[0009] Further, in the conventional terminal apparatuses, there are models that are difficult to judge whether or not content stored in the content storage medium is available. In such a case, for example, assuming that audio data is stored as the content in the content storage medium, there is a possibility that even when the audio data is not authorized data for a terminal apparatus, the terminal apparatus plays back the data, resulting in a problem that inconvenience occurs such that a high-level sound flows out.
DISCLOSURE OF INVENTION
[0010] It is an object of the present invention to provide a content processing apparatus, content storage medium, content processing method and content processing program enabling a plurality of pieces of content stored in the content storage medium to be distinguished readily from one another.
[0011] The object is achieved by associating information with a small data amount related to encrypted content stored in a content storage medium with the encrypted content to store in the content storage medium, and thereby distinguishing between encrypted content based on the related information without decoding the encrypted content with a large data amount.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 is an appearance view of a content processing apparatus according to Embodiment 1 of the present invention;
[0013] FIG. 2 is a block diagram illustrating a configuration of the content processing apparatus according to Embodiment 1;
[0014] FIG. 3 is a flowchart illustrating procedures of content write-out processing in the content processing apparatus according to Embodiment 1;
[0015] FIG. 4 is a schematic chart illustrating data stored in a content storage medium according to Embodiment 1 of the present invention;
[0016] FIG. 5 is a flowchart illustrating procedures of content read-in processing in the content processing apparatus according to Embodiment 1
of the present invention;
[0017] FIG. 6 is a block diagram illustrating a configuration of a content processing apparatus according to Embodiment 2;
[0018] FIG. 7 is a flowchart illustrating procedures of content write-out processing in the content processing apparatus according to Embodiment 2;
[0019] FIG. 8 is a schematic chart illustrating data stored in a content storage medium according to Embodiment 2 of the present invention;
[0020] FIG. 9 is a flowchart illustrating procedures of content read-in processing in the content processing apparatus according to Embodiment 2
of the present invention;
[0021] FIG. 10 is a block diagram illustrating a configuration of a content processing apparatus according to Embodiment 3;
[0022] FIG. 11 is a flowchart illustrating procedures of content write-out processing in the content processing apparatus according to Embodiment 3;
[0023] FIG. 12 is a schematic chart illustrating data stored in a content storage medium according to Embodiment 3 of the present invention;
[0024] FIG. 13 is a flowchart illustrating procedures of content read-in processing in the content processing apparatus according to Embodiment 3
of the present invention;
[0025] FIG. 14 is a block diagram illustrating a configuration of a content processing apparatus according to Embodiment 4;
[0026] FIG. 15 is a flowchart illustrating procedures of content write-out processing in the content processing apparatus according to Embodiment 4;
[0027] FIG. 16 is a schematic chart illustrating data stored in a content storage medium according to Embodiment 4 of the present invention;
[0028] FIG. 17 is a flowchart illustrating procedures of content read-in processing in the content processing apparatus according to Embodiment 4
of the present invention;
[0029] FIG. 18 is a block diagram illustrating a configuration of a content processing apparatus according to Embodiment 5;
[0030] FIG. 19 is a flowchart illustrating procedures of content write-out processing in the content processing apparatus according to Embodiment 5;
[0031] FIG. 20 is a schematic chart illustrating data stored in a content storage medium according to Embodiment 5 of the present invention;
[0032] FIG. 21 is a flowchart illustrating procedures of content read-in processing in the content processing apparatus according to Embodiment 5
of the present invention;
[0033] FIG. 22 is a block diagram illustrating a configuration of a content processing apparatus according to Embodiment 6;
[0034] FIG. 23 is a flowchart illustrating procedures of content write-out processing in the content processing apparatus according to Embodiment 6;
[0035] FIG. 24 is a schematic chart illustrating data stored in a content storage medium according to Embodiment 6 of the present invention;
[0036] FIG. 25 is a flowchart illustrating procedures of content read-in processing in the content processing apparatus according to Embodiment 6
of the present invention;
[0037] FIG. 26 is a block diagram illustrating a configuration of a content processing apparatus according to Embodiment 7;
[0038] FIG. 27 is a flowchart illustrating procedures of content write-out processing in the content processing apparatus according to Embodiment 7;
[0039] FIG. 28 is a schematic chart illustrating data stored in a content storage medium according to Embodiment 7 of the present invention; and
[0040] FIG. 29 is a flowchart illustrating procedures of content read-in processing in the content processing apparatus according to Embodiment 7
of the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0041] Embodiments of the present invention will be specifically described below with reference to accompanying drawings.
Embodiment 1
[0042] FIG. 1 is a front view showing an appearance of cellular phone 101
as a content processing apparatus according to Embodiment 1 of the present invention.
[0043] Cellular phone 101 has a cellular phone function section for communicating with other telephone apparatuses via cellular phone networks, and downloads various kinds of content such as music and games from a content provider via the cellular phone networks.
[0044] Cellular phone 101 further has memory card interface (I/F) 106
enabling a card-shaped recording medium (memory card 102) that is a content storage medium to be detachable, and writes (hereinafter referred to as information write) various information such as content stored in internal memory of cellular phone 101 in memory card 102 inserted into memory card interface 106, while reading (hereinafter referred to as information read) various information such as content stored in memory card 102.
[0045] Input interface (I/F) 117 comprised of operation buttons is provided in the front portion of the housing of cellular phone 101. By operating input interface 117, a user is able to input telephone numbers when using the cellular phone function, and, in addition, input various commands such as for content download, write and read of various information in/from memory card 102, and so on.
[0046] Further, liquid crystal screen 116 of a liquid crystal display section is provided at the front portion of the housing of cellular phone 101, and displays information on the operation of cellular phone 101, various kinds of information on execution of content and information of the content.
[0047] FIG. 2 is a block diagram illustrating a configuration of cellular phone 101 with the same reference numerals assigned to the same sections as in FIG. 1. FIG. 2 particularly shows a structure concerning content processing among the configuration of cellular phone 101. Cellular phone 101 includes memory write program 107, memory read program 108, encryption/decryption program 109 and encrypted identification data judgment program 110, each operated by a CPU (Central Processing Unit) not shown.
[0048] In FIG. 2, cellular phone 101 stores content 112 downloaded from a content provider via cellular phone networks in RAM (Random Access Memory) 111. Encryption/decryption program 109 is to encrypt content 112
stored in RAM 111. Content 112 encrypted by encryption/decryption program 109 is written in memory card 102 as encrypted content 104 by memory write program 107 via memory card interface 106.
[0049] ROM (Read Only Memory) 113 stores terminal identifier 114 comprised of, for example, a telephone number unique to cellular phone 101, and identification data 115 comprised of, for example, a character sequence common to systems for writing or reading content in/from the memory card as described in this Embodiment.
[0050] Encryption/decryption program 109 encrypts content 112 using terminal identifier 114 stored in ROM (Read Only Memory) 113. Further, when encrypting content 112 to store in memory card 102, encryption/decryption program 109 encrypts identification data 115 stored in ROM 113 using terminal identifier 114. Memory write program 107 stores encrypted identification data 105 that is a result of the encryption in the same directory as that of encrypted content 104 in memory card 102. Thus, encrypted identification data 105 is stored in the same directory as that of encrypted content 104, whereby encrypted identification data 105 and encrypted content 104 is stored in memory card 102 in association with each other.
[0051] When encrypted content 104 stored in memory card 102 is read into cellular phone 101, memory read program 108 of cellular phone 101 reads encrypted identification data 105, which is stored in the same directory as that of encryption content 104, from memory card 102 via memory card interface 106, prior to the processing for reading encrypted content 104.
[0052] Read encrypted identification data 105 is decoded by encrypted identification data judgment program 110. In this case, encrypted identification data judgment program 110 decodes the encrypted identification data using terminal identifier 114 unique to cellular phone 101 stored in ROM 113, compares the decoded identification data with identification data 115 stored in ROM 113, and when the comparison result indicates agreement, is capable of judging that the decoded encrypted identification data 105 in memory card 102 is data that is written in memory card 102 by cellular phone 101.
[0053] Thus, when it is recognized that encrypted identification data 105
stored in memory card 102 is data that is written in memory card 102 by cellular phone 101, encryption/decryption program 109 decodes encrypted content 104 stored in the same directory as that of the encrypted identification data 105, and stores the decoded content 112 in RAM 111.
[0054] FIG. 3 is a flowchart illustrating processing procedures of encryption/decryption program 109 in storing in memory card 102 content 112 stored in RAM 111 of cellular phone 101.
[0055] As shown in FIG. 3, encryption/decryption program 109 acquires identification data 115 and terminal identifier 114 from ROM 113 in step ST201. Then, encryption/decryption program 109 shifts to step ST202, encrypts identification data 115 acquired in step ST201, for example, in the triple DES (Data encryption Standard) encryption scheme, using terminal identifier 114 unique to cellular phone 101 acquired in step ST201, and thereby generates encrypted identification data 105.
[0056] Encryption/decryption program 109 shifts to step ST203, and judges whether or not the same encrypted identification data as the encrypted identification data 105 generated in step ST202 is already stored in memory card 102 inserted into memory card interface 106. The negative result obtained in this step means that memory card 102 does not store encrypted identification data 105 encrypted using terminal identifier 114
unique to cellular phone 101 i.e. encrypted identification data 105
written by cellular phone 101. At this point, encryption/decryption program 109 shifts to step ST204, stores encrypted identification data 105 encrypted in step ST202 in memory card 102 using memory write program 107, and shifts to step ST205.
[0057] Meanwhile, the positive result obtained in step ST203 means that memory card 102 stores encrypted identification data 105 written by cellular phone 101, and at this point, encryption/decryption program 109
shifts to step ST205.
[0058] After acquiring content 112 from RAM 111 in step ST205, encryption/decryption program 109 shifts to step ST206, and encrypts content 112 acquired in step ST205, for example, in the triple DES encryption scheme, using terminal identifier 114 in ROM 113.
[0059] Then, encryption/decryption program 109 shifts to step ST207, and stores encrypted content 104 encrypted in step ST206 in the same directory as that of encrypted identification data 105 stored in memory card 102 in step ST204.
[0060] In this way, as shown in FIG. 4, in memory card 102, content 112
(encrypted content 104) and identification data 115 (encrypted identification data 105) both encrypted using the same terminal identifier 114 is stored in the same directories 301 and 302. Thus, by storing encrypted content 104 and encrypted identification data 105 in the same directory, the data is stored in memory card 102 in association with one another.
[0061] FIG. 5 is a flowchart illustrating processing procedures of encryption/decryption program 109 and encrypted identification data judgment program 110 when cellular phone 101 reads and decodes encrypted content 104 and encrypted identification data stored in memory card 102
in the processing procedures in FIG. 3.
[0062] As shown in FIG. 5, in step ST401, encrypted identification data judgment program 110 checks whether encrypted identification data 105 is present in memory card 102. The negative result obtained in this step means that memory card 102 does not have encrypted identification data 105 to read i.e. encrypted content 104 associated with the encrypted identification data 105. In this case, encrypted identification data judgment program 110 finishes the processing procedures.
[0063] In contrast thereto, the positive result obtained in step ST401
means that memory card 102 has encrypted identification data 105 to read i.e. encrypted content 104 associated with the encrypted identification data 105. In this case, encrypted identification data judgment program 110 shifts to step ST402, acquires the encrypted identification data 105
from memory card 102 using memory read program 108, and shifts to step ST403. In step ST403, encrypted identification data judgment program 110
decodes the encrypted identification data 105 acquired in step ST402
using terminal identifier 114 stored in ROM 113.
[0064] Then, encrypted identification data judgment program 110 shifts to step ST404, compares the identification data decoded in step ST403 with identification data 115 stored in ROM 113, and judges whether the decoded identification data is the same as identification data 115 stored in ROM 113.
[0065] When cellular phone 101 encrypts content 112 and writes in memory card 102, encrypted identification data 105 obtained by encrypting identification data 115 using terminal identifier 114 is always stored in association with encrypted content 104. Accordingly, when the identification data decoded in step ST403 is in agreement with identification data 115 stored in ROM 113 as a result of comparison, it is meant that the decoded encrypted identification data 105 is written in memory card 102 by cellular phone 101, in other words, encrypted content 104 stored in memory card 102 in association with the encrypted identification data 105 is written in memory card 102 by cellular phone 101.
[0066] Accordingly, when the identification data decoded in step ST403 is in agreement with identification data 115 stored in ROM 113 as a result of comparison, encrypted identification data judgment program 110
notifies the result of agreement to encryption/decryption program 109, and shifts from step ST404 to step ST405.
[0067] In contrast thereto, when the identification data decoded in step ST403 is not in agreement with identification data 115 stored in ROM 113
as a result of comparison, encrypted identification data judgment program 110 notifies the result of disagreement to encryption/decryption program 109, returns to step ST401, judges whether or not memory card 102 has another encrypted identification data, and when another encrypted identification data exists, executes the same processing on the encrypted identification data.
[0068] In step ST405, encrypted identification data judgment program 110
instructs encryption/decryption program 109 to decode the encrypted identification data 105 with the result of agreement in step ST404, and all items of encrypted identification data stored in directory 302
storing the encrypted identification data 105, and displays a list of the data on liquid crystal screen 116.
[0069] By this means, liquid crystal screen 106 displays the list of identification data 115 associated with encrypted content 104 available in cellular phone 101 among encrypted content stored in memory card 102. In other words, the encrypted content 104 available in cellular phone 101
is displayed in list form using identification data 115 which is associated with the content 104 and has a small data amount.
[0070] In addition, this Embodiment describes the case of decoding encrypted identification data 105 associated with encrypted content 104
to display in list form. However, the present invention is not limited to such a case, and it may be possible to store only a title of content corresponding to identification data 115 in RAM 111 of cellular phone 101
when encrypted content 104 is stored in memory card 102 in association with the identification data 115, and display in list form the stored title based on a result on whether the identification data 105 is in agreement in step ST404.
[0071] When the list of content is displayed on liquid crystal screen 116
in step ST405, a user operates input interface 117, and thereby selects desired content from the displayed list.
[0072] By this means, encryption/decryption program 109 shifts to step ST406, and, using memory read program 108, reads encrypted content 104
designated through input interface 117 from memory card 102, shifts to a subsequent step, ST407, and using terminal identifier 114 stored in ROM 113, decodes the encrypted content 104 acquired from memory card 102 in step ST406 to store in RAM 111.
[0073] Content 111 stored in RAM 111 is initiated by a user of cellular phone 101 operating input interface 117, and used for the user.
[0074] In the aforementioned constitution, when writing encrypted content 104 in memory card 102, cellular phone 101 stores encrypted identification data 105 associated with the encrypted content 104 in memory card 102.
[0075] The encrypted identification data 105 is, for example, obtained by encrypting some character sequence, and thus has a data amount extremely smaller than that of encrypted content 104. Accordingly, before reading encrypted content 104 from memory card 102 to decode, cellular phone 101
reads encrypted identification data 105 associated with the encrypted content 104 to decode, and determines whether or not the decoded identification data is written in memory card 102 by cellular phone 101.
[0076] When the decoded identification data is data written in memory card 102 by cellular phone 101, encrypted content 104 stored in memory card 102 in association with the identification data is also data written in memory card 102 by cellular phone 101.
[0077] Accordingly, in this case, encrypted content 104 stored in memory card 102 can be read into cellular phone 101 to be used therein, and encryption/decryption program 109 reads encrypted content 104 from memory card 102, and decodes the read encrypted content 104.
[0078] In this way, on the condition that a result of decoding of encrypted identification data 105 is in agreement with identification data 115 stored in ROM 113, cellular phone 101 reads encrypted content 104 associated with the encrypted identification data 105 from memory card 102, and thus is capable of selecting and decoding only encrypted content 104 available in cellular phone 101.
[0079] Accordingly, when a plurality of pieces of encrypted content is stored in memory card 102 and terminal apparatuses (such as cellular phones) capable of using the plurality of encrypted content vary with each encrypted content, cellular phone 101 does not need to decode all the plurality of encrypted content with a large data amount, and by decoding only encrypted identification data with a small data amount associated with each of the plurality of encrypted content, is capable of determining available encrypted content 104.
[0080] In this way, according to cellular phone 101 as a content processing apparatus in this Embodiment, it is possible to more readily distinguish between a plurality of pieces of encrypted content stored in memory card 102 that is a content storage medium, and more promptly decode encrypted content 104 available in cellular phone 101.
[0081] In addition, this Embodiment describes the case where a telephone number of cellular phone 101 is used as terminal identifier 114 in cellular phone 101, but the present invention is not limited to such a case. For example, it may be possible to use an identifier for identifying cellular phone 101 such as a serial number of cellular phone 101, data such as a character sequence having some meaning, numeric value, image and audio, or an identifier (such as a membership number) indicating a contract with particular service. Further, as well as using as terminal identifier 114 a telephone number, serial number or other information such as a character sequence without any processing, such a terminal identifier may be converted to be used (as information related to the terminal identifier). By this means, when an encryption method in encrypting content and identification data using the terminal identifier and/or the terminal identifier leaks to a third party, since the terminal identifier is converted into another data usable as an encryption key, it is possible to prevent interpretation of the encrypted content and encrypted identification data that is encrypted using the data (encryption key).
[0082] Further, this Embodiment describes the case of using as identification data 115 data such as a character sequence common to systems for writing or reading content in/from a memory card in cellular phone 101, but the present invention is not limited to such a case. It may be possible to use another identifier different from information set as a terminal identifier (for example, when a telephone number is set as terminal identifier 114, a serial number may be used as identification data), data such as a character sequence with some meaning, numeric value, image and audio, or an identifier (such as a membership number) indicating a contract with particular service.
[0083] Furthermore, this Embodiment describes the case of using memory card 102 as a content storage medium to store content, but the present invention is not limited to such a case. As long as a device is a content storage medium capable of storing digitalized content, other devices are widely applied.
Embodiment 2
[0084] FIG. 6 is a block diagram illustrating a configuration of cellular phone 501 as a content processing apparatus according to Embodiment 2 of the present invention. In addition, the same sections as those in FIGS. 1
and 2 are assigned the same reference numerals as those in FIGS. 1 and 2, and specific descriptions thereof are omitted.
[0085] Cellular phone 501 as shown in FIG. 6 differs from cellular phone 101 with the configuration as shown in FIG. 2 in the respects that cellular phone 501 has authentication program 510, memory card 502 is provided with authentication area 503 to which access is enabled by performing authentication using authentication program 510, and that authentication area 503 stores encrypted identification data 504.
[0086] FIG. 6 is a block diagram illustrating the configuration of cellular phone 501 with the same reference numerals assigned to the same sections as in FIG. 2. FIG. 6 particularly shows a structure concerning content processing among the configuration of cellular phone 501. Cellular phone 501 includes memory write program 107, memory read program 108, encryption/decryption program 513, encrypted identification data judgment program 514, and authentication program 510, each operated by a CPU (Central Processing Unit) not shown.
[0087] In FIG. 6, cellular phone 501 stores content 516 downloaded from a content provider via cellular phone networks in RAM (Random Access Memory) 515. Encryption/decryption program 513 is to encrypt content 516
stored in RAM 515. Content 516 encrypted by encryption/decryption program 513 is written in general area 505 of memory card 502 by memory write program 107 via memory card interface 106. General area 505 is an area which is provided in cellular phone 501 and accessible with eliminating the need of authentication processing of authentication program 510.
[0088] ROM (Read Only Memory) 517 stores terminal identifier 518 comprised of, for example, a telephone number unique to cellular phone 501, and identification data 519 comprised of, for example, a character sequence common to systems for writing or reading content in a memory card shown in this Embodiment.
[0089] Upon encrypting content 516, encryption/decryption program 513
encrypts content 516 using terminal identifier 518 stored in ROM (Read Only Memory) 517. Further, when encrypting content 516 to store in memory card 502, encryption/decryption program 513 encrypts identification data 519 stored in ROM 517 using terminal identifier 518. Memory write program 107 stores encrypted identification data 504 that is a result of the encryption in authentication area 503 in memory card 502. Encrypted identification data 504 in authentication area 503 is associated with encrypted content 507 via link information 508 stored in the same directory as the directory in which encrypted content 507 of general area 505 is stored. Thus, encrypted identification data 504 and encrypted content 507 is associated with each other via link information 508, and is separately stored in authentication area 503 and general area 505, respectively.
[0090] When encrypted content 507 stored in memory card 502 is read into cellular phone 501, memory read program 108 of cellular phone 501 reads encrypted identification data 504 in authentication area 503 associated with the encrypted content 507 via link information 508 stored in the same directory as that of the encryption content 507, from memory card 502 via memory card interface 106, prior to the processing for reading the encrypted content 507.
[0091] Read encrypted identification data 504 is decoded by encrypted identification data judgment program 514. In this case, encrypted identification data judgment program 514 decodes the encrypted identification data 504 using terminal identifier 518 unique to cellular phone 501 stored in ROM 517, and when the decoded identification data is in agreement with identification data 519 stored in ROM 517, judges that the decoded encrypted identification data 504 in memory card 502 is data that is written in memory card 502 by cellular phone 501.
[0092] Thus, when it is determined that encrypted identification data 504
stored in memory card 502 is data that is written in memory card 502 by cellular phone 501, encryption/decryption program 513 decodes encrypted content 507 in general area 505 associated with the encrypted identification data 504, and stores the decoded content 516 in RAM 515.
[0093] FIG. 7 is a flowchart illustrating processing procedures of authentication program 510 and encryption/decryption program 513 in storing in memory card 501 content 516 stored in RAM 516 of cellular phone 501.
[0094] As shown in FIG. 7, in step ST601, authentication program 510
performs authentication with memory card 502. In addition, memory card 502 is provided with an authentication program not shown, executes authentication processing with authentication program 510 of cellular phone 501, and when such a result is obtained as the authentication result that cellular phone 501 is a terminal device allowed to gain access to authentication area 503 of memory card 502, permits access to authentication area 503.
[0095] When the access is allowed to authentication area 503 of memory card 502 from cellular phone 501 as a result of the authentication processing in step ST601, authentication program 510 notifies encryption/decryption program 513 of the authentication result. Encryption/decryption program 513 having received the notification acquires identification data 519 from ROM 517 in step ST602. Then, encryption/decryption program 513 shifts to step ST603, encrypts the identification data 519 acquired in step ST602, for example, in the triple DES encryption scheme, using terminal identifier 518 unique to cellular phone 501 stored in ROM 517, and thereby generates encrypted identification data 504.
[0096] Encryption/decryption program 513 shifts to step ST604, and judges whether the same encrypted identification data as the encrypted identification data 504 generated in step ST603 is already stored in authentication area 503 in memory card 502 inserted into memory card interface 106. The negative result obtained in this step means that memory card 502 does not store encrypted identification data 504
encrypted using terminal identifier 518 unique to cellular phone 501 i.e. encrypted identification data 504 written by cellular phone 501. At this point, encryption/decryption program 513 shifts to step ST605, stores the encrypted identification data 504 encrypted in step ST603 and link information 508 in memory card 502 using memory write program 107, and shifts to step ST606. In this case, encryption/decryption program 513
stores encrypted identification data 504 in authentication area 503, while storing link information 508 in content storage directory 506 in general area 505. Link information 508 is information for associating encrypted identification data 504 stored in authentication area 503 with encrypted content 507 in general area 505 associated with the data 504.
[0097] Meanwhile, the positive result obtained in step ST604 means that memory card 502 stores encrypted identification data 504 written by cellular phone 501. In this case, encryption/decryption program 513
shifts to step ST606.
[0098] After acquiring content 516 from RAM 515 in step ST606, encryption/decryption program 513 shifts to step ST607, and encrypts the content 516 acquired in step ST606, for example, in the triple DES encryption scheme, using terminal identifier 518 in ROM 517.
[0099] Then, encryption/decryption program 513 shifts to step ST608, and stores encrypted content 507 encrypted in step ST607 in the directory associated by link information 508 with encrypted identification data 504
stored in memory card 502 in step ST605.
[0100] In this way, as shown in FIG. 8, in memory card 502, content 516
(encrypted content 507) and identification data 519 (encrypted identification data 504) both encrypted using the same terminal identifier 518 is stored in memory card 502 in association with one another via link information 508. Thus, by associating encrypted content 507 with encrypted identification data 504 via link information 508, while storing encrypted identification data 504 to confirm the presence of encrypted content 507 in authentication area 503, it is made possible only for cellular phone 501 accessible to authentication area 503 to confirm the presence of encrypted content 507.
[0101] FIG. 9 is a flowchart illustrating processing procedures of encryption/decryption program 513 and encrypted identification data judgment program 514 when cellular phone 501 reads and decodes encrypted content 507 and encrypted identification data 504 stored in memory card 502 in the processing procedures in FIG. 7.
[0102] As shown in FIG. 9, in step ST701, encrypted identification data judgment program 514 checks whether or not link information 508 is present in general area 505 in memory card 502. The negative result obtained in this step means that link information 508 is not stored in memory card 502 i.e. encrypted content 507 is not stored. In this case, encrypted identification data judgment program 514 finishes the processing procedures.
[0103] In contrast thereto, the positive result obtained in step ST701
means that link information 508 is stored in memory card 502, i.e. encrypted content 507 is present. In this case, encrypted identification data judgment program 514 shifts to step ST702, performs authentication processing by authentication program 510, and acquires encrypted identification data 504 corresponding to link information 508 from authentication area 503 in memory card 502 using memory read program 108.
[0104] Then, encrypted identification data judgment program 514 shifts to step ST703, and decodes the encrypted identification data 504 acquired in step ST702 using terminal identifier 518 stored in ROM 517.
[0105] Encrypted identification data judgment program 514 shifts to step ST704, compares the identification data decoded in step ST703 with identification data 519 stored in ROM 517, and judges whether the decoded identification data is the same as identification data 519 stored in ROM 517.
[0106] When cellular phone 501 encrypts content 516 to write in memory card 502, encrypted identification data 504 obtained by encrypting identification data 519 using terminal identifier 518 is always stored in association with encrypted content 507. Accordingly, when the identification data decoded in step ST703 is in agreement with identification data 519 stored in ROM 517 as a result of comparison, it is meant that the decoded encrypted identification data 504 is written in memory card 502 by cellular phone 501, in other words, encrypted content 507 stored in memory card 502 in association with the encrypted identification data 504 via link information 508 is written in memory card 502 by cellular phone 501.
[0107] Accordingly, when the identification data decoded in step ST703 is in agreement with identification data 519 stored in ROM 517 as a result of comparison, encrypted identification data judgment program 514
notifies the result of agreement to encryption/decryption program 513, and shifts from step ST704 to step ST705.
[0108] In contrast thereto, when the identification data decoded in step ST703 is not in agreement with identification data 519 stored in ROM 517
as a result of comparison, encrypted identification data judgment program 514 notifies the result of disagreement to encryption/decryption program 513, returns to step ST701, judges whether or not memory card 502 has another link information 508, and when another link information 508
exists, executes the same processing on the link information 508.
[0109] In step ST705, encrypted identification data judgment program 514
displays a list of identification data 519 with the result of agreement obtained in step ST704. In other words, encrypted content 507 available in cellular phone 501 is displayed in list form by identification data 519 which is associated with the content 507 and has a small data amount.
[0110] In addition, this Embodiment describes the case of decoding encrypted identification data 504 associated with encrypted content 507
to display in list form. However, the present invention is not limited to such a case, and it may be possible to store only a title of content corresponding to identification data 516 in RAM 515 of cellular phone 501
when encrypted content 507 is stored in memory card 502 in association with the identification data 516, and display in list form the stored title based on a result on whether identification data 519 is in agreement in step ST704.
[0111] When a list of content is displayed on liquid crystal screen 116 in step ST705, a user operates input interface 117, and thereby selects desired content from the displayed list.
[0112] By this means, encryption/decryption program 513 shifts to step ST706, using memory read program 108, reads encrypted content 507
designated through input interface 117 from memory card 502, shifts to a subsequent step, ST707, and using terminal identifier 518 stored in ROM 517, decodes the encrypted content 507 acquired from memory card 502 in step ST706 to store in RAM 518.
[0113] Content 516 stored in RAM 515 is initiated by a user of cellular phone 501 operating input interface 117, and used for the user.
[0114] In the aforementioned constitution, when writing encrypted content 507 in memory card 502, cellular phone 501 stores encrypted identification data 504 associated with the encrypted content 507 in authentication area 503 in memory card 502.
[0115] The encrypted identification data 504 is, for example, obtained by encrypting some character sequence, and thus has a data amount extremely smaller than that of encrypted content 507. Accordingly, before reading encrypted content 507 from memory card 502 to decode, cellular phone 501
reads encrypted identification data 504 associated with the encrypted content 507 to decode, and determines whether or not the decoded identification data is written in memory card 502 by cellular phone 501. It is thereby possible to readily judge whether or not content available in cellular phone 501 is present in memory card 502 based on identification data with a small data amount.
[0116] In the case of this Embodiment, encrypted identification data 504
is stored in authentication area 503, whereby access to authentication area 503 in memory card 502 from cellular phone 501 is executed after carrying out the authentication processing. Accordingly, terminal apparatuses except cellular telephone 501 accessible to o authentication area 503 are hard to acquire encrypted identification data 504, and difficult to readily determine available encrypted content.
[0117] In this way, according to cellular phone 501 as a content processing apparatus in this Embodiment, it is possible to more readily distinguish between a plurality of pieces of encrypted content stored in memory card 502 that is a content storage medium only in cellular phone 501 capable of performing authentication.
[0118] In addition, this Embodiment describes the case where a telephone number of cellular phone 501 is used as terminal identifier 518 in cellular phone 501, but the present invention is not limited to such a case. For example, it may be possible to use an identifier for identifying cellular phone 501 such as a serial number of cellular phone 501, data such as a character sequence with some meaning, numeric value, image and audio, or an identifier (such as membership number) indicating a contract with particular service. Further, as well as using as terminal identifier 518 a telephone number, serial number or other information such as a character sequence without any processing, such a terminal identifier may be converted to be used (as information related to the terminal identifier). By this means, when an encryption method in encrypting content and identification data using the terminal identifier and/or the terminal identifier leaks to a third party, since the terminal identifier is converted into another data usable as an encryption key, it is possible to prevent interpretation of the encrypted content and encrypted identification data that is encrypted using the data (encryption key).
[0119] Further, this Embodiment describes the case of using as identification data 519 data such as a character sequence common to systems for writing or reading content in/from a memory card in cellular phone 501, but the present invention is not limited to such a case. It may be possible to use another identifier different from information set as a terminal identifier (for example, when a telephone number is set as terminal identifier 518, a serial number may be used as identification data), data such as a character sequence with some meaning, numeric value, image and audio, or an identifier (such as a membership number) indicating a contract with particular service.
[0120] Furthermore, this Embodiment describes the case of specifying encrypted identification data in the authentication area using link information stored in the general area, but the present invention is not limited to such a case. For example, information (such as a route name and directory name) indicating a storage location in the general area of the encrypted content stored in the general area may be made the same as information (such as a route name and directory name) indicating a storage location in the authentication area of the encrypted identification data stored in the authentication area corresponding to the information of the content. By thus preparing the same directory structure, it is possible to associate encrypted identification data in the authentication area with the encrypted content in the general area without using link information.
[0121] Moreover, this Embodiment describes the case of using memory card 502 as a content storage medium to store content, but the present invention is not limited to such a case. As long as a device is a content storage medium capable of storing digitalized information, other devices are widely applied.
Embodiment 3
[0122] FIG. 10 is a block diagram illustrating a configuration of cellular phone 901 as a content processing apparatus according to Embodiment 3 of the present invention. In addition, the same sections as those in FIGS. 1
and 2 are assigned the same reference numerals as those in FIGS. 1 and 2, and specific descriptions thereof are omitted.
[0123] Cellular phone 901 as shown in FIG. 10 differs from cellular phone 101 with the configuration as shown in FIG. 2 in the respects that used as terminal identifier 914 stored in ROM 913 is a name of a directory that stores encrypted content 905 in memory card 902, and that the directory name is used as a substitute for identification data 115 (FIG. 2).
[0124] FIG. 10 is a block diagram illustrating the configuration of cellular phone 901 with the same reference numerals assigned to the same sections as in FIG. 2. FIG. 10 particularly shows a structure concerning content processing among the configuration of cellular phone 901. Cellular phone 901 includes memory write program 107, memory read program 108, encryption/decryption program 909 and content storage directory determination program 910, each operated by a CPU (Central Processing Unit) not shown.
[0125] In FIG. 10, cellular phone 901 stores content 912 downloaded from a content provider via cellular phone networks in RAM (Random Access Memory) 911. Encryption/decryption program 909 is to encrypt content 912
stored in RAM 911. Content 912 encrypted by encryption/decryption program 909 is written in memory card 902 by memory write program 107 via memory card interface 106, as encrypted content 905.
[0126] ROM (Read Only Memory) 913 stores terminal identifier 914 that is an identifier comprised of a predetermined character sequence unique to cellular phone 901 and that is used as directory name 904 in storing encrypted content in memory card 902.
[0127] Encryption/decryption program 909 encrypts content 912 using terminal identifier 914 stored in ROM (Read Only Memory) 913. Further, when storing the content 912 (encrypted content 905) encrypted in memory card 902, encryption/decryption program 909 uses terminal identifier 914
stored in ROM 913 as directory name 904 of content storage directory (hereinafter, simply referred to as a directory) 903 that is a storage destination.
[0128] In the case where encrypted content 905 stored in memory card 902
is read into cellular phone 901, memory read program 108 of cellular phone 901 acquires the directory name storing the encrypted content 905
from memory card 902, prior to the processing for reading the encrypted content 905, and when the acquired directory name is in agreement with terminal identifier 914 stored in ROM 913, is capable of judging that the acquired directory name is set in memory card 902 by cellular phone 901.
[0129] Thus, when it is determined that the acquired directory name in memory card 902 is set in memory card 902 by cellular phone 901, encryption/decryption program 909 decodes encrypted content 905 stored in directory 903 with the directory name 904, and stores the decoded content 912 in RAM 911.
[0130] FIG. 11 is a flowchart illustrating processing procedures of encryption/decryption program 909 in storing in memory card 902 content 912 stored in RAM 911 of cellular phone 901.
[0131] As shown in FIG. 11, encryption/decryption program 909 acquires terminal identifier 914 from ROM 913 in step ST1001. Then, encryption/decryption program 909 shifts to step ST1002, and judges whether or not directory 903 with the terminal identifier name acquired in step ST1001 is present in memory card 902.
[0132] The negative result obtained in this step means that memory card 902 does not have directory 903 set by cellular phone 901. At this point, encryption/decryption program 909 shifts to step ST1003, generates directory 903 with the terminal identifier name stored in ROM 913, and shifts to step ST1004.
[0133] Meanwhile, the positive result obtained in step ST1002 means that directory 903 generated by cellular phone 901 is already present in memory card 902, and at this point, encryption/decryption program 909
shifts to step ST1004.
[0134] After acquiring content 912 from RAM 911 in step ST1004, encryption/decryption program 909 shifts to step ST1005, and encrypts the content 912 acquired in step ST1004, for example, in the triple DES encryption scheme, using terminal identifier 914 in ROM 913.
[0135] Then, encryption/decryption program 909 shifts to step ST1006, and stores encrypted content 905 encrypted in step ST1005 in directory 903
generated in step ST1003.
[0136] In this way, as shown in FIG. 12, in memory card 902, content 912
(encrypted content 905) encrypted using the same terminal identifier 914, i.e. encrypted content 905 written by a single cellular phone 901 is stored in directory 903 with the terminal identifier name unique to cellular phone 901.
[0137] FIG. 13 is a flowchart illustrating processing procedures of encryption/decryption program 909 and content storage directory determination program 910 when cellular phone 901 reads encrypted content 905 stored in memory card 902 in the processing procedures in FIG. 11 to decode.
[0138] As shown in FIG. 13, in step ST1201, content storage directory determination program 910 checks whether or not a directory is present in memory card 902. The negative result obtained in this step means that memory card 902 does not have encrypted content 905 to read, and content storage directory determination program 910 finishes the processing procedures.
[0139] In contrast thereto, the positive result obtained in step ST1201
means that memory card 902 has encrypted content 905 to read, and content storage directory determination program 910 shifts to step ST1202, acquires a directory name from memory card 902 using memory read program 108, and shifts to step ST1203. In step ST1203, content storage directory determination program 910 judges whether or not the directory name acquired in step ST1202 is the same as terminal identifier 914 stored in ROM 913.
[0140] The negative result obtained in this step means that the directory name acquired from memory card 902 is not directory name 904 set by cellular phone 901, i.e. that encrypted content stored in the directory of the name is not available in cellular phone 901. At this point, content storage directory determination program 910 notifies the result of disagreement to encryption/decryption program 909, returns to step ST1201, judges whether or not another directory is present in memory card 902, and when another directory exists, executes the same processing on the directory.
[0141] In contrast thereto, the positive result obtained in step ST1203
means that the acquired directory is set by cellular phone 901, i.e. that encrypted content stored in the directory is available in cellular phone 901, and at this point, content storage directory determination program 910 notifies the result of agreement to encryption/decryption program 909, and returns to step ST1204.
[0142] In step ST1204, content storage directory determination program 910
displays in list form on liquid crystal screen 116 the information of directory 904 with the result of agreement in step ST1203, or information (for example, a tile) related to encrypted content 905 stored in the directory.
[0143] In this way, liquid crystal screen 116 displays information related to encrypted content 905 available in cellular phone 901 among encrypted content stored in memory card 902.
[0144] In addition, as a constitution for displaying in list form the information on encrypted content 905 available in cellular phone 901, for example, a method is considered of storing only limited information such as a title corresponding to encrypted content 905 in RAM 911 of cellular phone 901 in storing the encrypted content 905 in memory card 902, and displaying in list form the stored limited information based on the result of agreement in step ST1203.
[0145] In step ST1204, when a list of content is displayed on liquid crystal screen 116, a user operates input interface 117, and thereby selects desired content from the displayed list.
[0146] By this means, encryption/decryption program 909 shifts to step ST1205, reads encrypted content 905 designated through input interface 117 from memory card 902 using memory read program 108, shifts to a subsequent step ST1206, and decodes the encrypted content 905 acquired from memory card 902 in step ST1205, using terminal identifier 914 stored in ROM 913, to store in RAM 911.
[0147] Content 912 stored in RAM 911 is initiated by the user of cellular phone 901 operating input interface 117, and used by the user.
[0148] In the aforementioned constitution, cellular phone 901 uses terminal identifier 914 unique to cellular phone 901 as a name of directory 904 to store content 905, in writing encrypted content 905 in memory card 902.
[0149] The directory name has a data amount extremely smaller than that of encrypted content 905. Accordingly, before reading encrypted content 905
from memory card 902 to decode, cellular phone 901 reads the directory name of directory 904 storing the encrypted content 905, and determines whether or not the directory name agrees with terminal identifier 914 of cellular phone 901.
[0150] When the directory name agrees with terminal identifier 914 of cellular phone 901, it is meant that encrypted content 905 stored in directory 904 with the directory name is written in memory card 902 by cellular phone 901.
[0151] Accordingly, it is possible to read the encrypted content 905 into cellular phone 901 to be used in cellular phone 901, and encryption/decryption program 909 reads the encrypted content 905 from memory card902, and decodes the read encrypted content 905.
[0152] Thus, on the condition that a directory name is in agreement with terminal identifier 914 stored in ROM 913, encrypted content 905 stored in directory 904 with the directory name is read into cellular phone 901
from memory card 902 to be decode, whereby cellular phone 901 is capable of selecting only encrypted content 905 available in cellular phone 901
to decode.
[0153] Accordingly, when a plurality of pieces of encrypted content is stored in memory card 902 and terminal apparatuses (such as cellular telephones) capable of using the plurality of encrypted content vary with each encrypted content, cellular phone 901 does not need to decode all the plurality of encrypted content with a large data amount, and only by acquiring a directory with a small data amount, is capable of determining available encrypted content 905.
[0154] In this way, according to cellular phone 901 as a content processing apparatus in this Embodiment, it is possible to more readily distinguish between a plurality of pieces of encrypted content stored in memory card 902 that is a content storage medium, and more promptly decode encrypted content 905 available in cellular phone 901. Further, according to cellular phone 901 as a content processing apparatus in this Embodiment, by using terminal identifier 914 stored in ROM 913 without any conversion as a directory name in memory card 902, it is possible to determine encrypted content 905 in a further simplified constitution.
[0155] In addition, this Embodiment describes the case of using memory card 902 as a content storage medium to store content, but the present invention is not limited to such a case. As long as a device is a content storage medium capable of storing digitalized information, other devices are widely applied.
Embodiment 4
[0156] FIG. 14 is a block diagram illustrating a configuration of cellular phone 1301 as a content processing apparatus according to Embodiment 4 of the present invention. In addition, the same sections as those in FIGS. 1
and 2 are assigned the same reference numerals as those in FIGS. 1 and 2, and specific descriptions thereof are omitted.
[0157] Cellular phone 1301 as shown in FIG. 14 differs from cellular phone 101 with the configuration as shown in FIG. 2 in the respects that cellular phone 1301 has authentication program 1309, memory card 1302 is provided with authentication area 1303 to which access is enabled by performing authentication using authentication program 1309, and that authentication area 1303 stores terminal identifier 1317 unique to the terminal apparatus (cellular phone 1301).
[0158] FIG. 14 is a block diagram illustrating the configuration of cellular phone 1301 with the same reference numerals assigned to the same sections as in FIG. 2. FIG. 14 particularly shows a structure concerning content processing among the configuration of cellular phone 1301. Cellular phone 1301 includes memory write program 107, memory read program 108, encryption/decryption program 1312, content storage directory determination program 1313, and authentication program 1309, each operated by a CPU (Central Processing Unit) not shown.
[0159] In FIG. 14, cellular phone 1301 stores content 1315 downloaded from a content provider via cellular phone networks in RAM (Random Access Memory) 1314. Encryption/decryption program 1312 is to encrypt content 1315 stored in RAM 1314. Content 1315 encrypted by encryption/decryption program 1312 is written in general area 1305 of memory card 1302 by memory write program 107 via memory card interface 106. General area 1305
is an area which is provided in cellular phone 1301 and accessible with eliminating the need of authentication processing of authentication program 1309.
[0160] ROM (Read Only Memory) 1316 stores terminal identifier 1317
comprised of, for example, a telephone number unique to cellular phone 1301.
[0161] Encryption/decryption program 1312 encrypts content 1315 using terminal identifier 1317 stored in ROM (Read Only Memory) 1316. Further, when encrypting content 1315 to store in memory card 1302, encryption/decryption program 1312 stores terminal identifier 1317 stored in ROM 1316 in authentication area 1303 of memory card 1302 using memory write program 107. Terminal identifier 1317 in authentication area 1303
is associated with encrypted content 1307 via link information 1308
stored in the same directory as the directory in which the encrypted content 1307 of general area 1305 is stored. Thus, terminal identifier 1317 and encrypted content 1307 is associated with each other via link information 1308, and is separately stored in authentication area 1303
and general area 1305, respectively.
[0162] When encrypted content 1307 stored in memory card 1302 is read into cellular phone 1301, memory read program 108 of cellular phone 1301 reads terminal identifier 1317 in authentication area 1303 associated with the content 1307 via link information 1308 stored in the same directory as that of encryption content 1307, from memory card 1302 via memory card interface 106, prior to the processing for reading encrypted content 1307.
[0163] Content storage directory determination program 1313 compares the read terminal identifier 1317 with terminal identifier 1317 unique to cellular phone 1301 stored in ROM 1316. When "agreement" is obtained as a result of the comparison, it is determined that terminal identifier 1317
stored in memory card 1302 is written in memory card 1302 by cellular phone 1301.
[0164] Thus, when it is recognized that terminal identifier 1317 stored in memory card 1302 is written in memory card 1302 by cellular phone 1301, encryption/decryption program 1312 decodes encrypted content 1307 in general area 1305 associated with terminal identifier 1317 in memory card 1302, and stores the decoded content 1315 in RAM 1314.
[0165] FIG. 15 is a flowchart illustrating processing procedures of authentication program 1309 and encryption/decryption program 1312 in storing in memory card 1302 content 1315 stored in RAM 1314 of cellular phone 1301.
[0166] As shown in FIG. 15, in step ST1401, authentication program 1309
performs authentication with memory card 1302. In addition, memory card 1302 is provided with an authentication program not shown, executes authentication processing with authentication program 1309 of cellular phone 1301, and when such a result is obtained as the authentication result that cellular phone 1301 is a terminal device accessible to authentication area 1303 of memory card 1302, permits access to authentication area 1303.
[0167] When the access is allowed to authentication area 1303 of memory card 1302 from cellular phone 1301 as a result of the authentication processing in step ST1401, authentication program 1309 notifies encryption/decryption program 1312 of the authentication result. Encryption/decryption program 1312 having received the notification acquires terminal identifier 1317 from ROM 1316 in step ST1402. Then, encryption/decryption program 1312 shifts to step ST1403, and judges whether or not the same terminal identifier as the terminal identifier 1317 acquired from ROM 1316 in step ST1402 is already stored in authentication area 1303 in memory card 1302 inserted into memory card interface 106. The negative result obtained in this step means that memory card 1302 does not store terminal identifier 1317 written by cellular phone 1301. At this point, encryption/decryption program 1312
shifts to step ST1404, stores terminal identifier 1317 acquired in step ST1402 and link information 1308 in memory card 1302 using memory write program 107, and shifts to step ST1405. In this case, encryption/decryption program 1312 stores terminal identifier 1317 in authentication area 1303, while storing link information 1308 in content storage directory 1306 in general area 1305. Link information 1308 is information for associating terminal identifier 1317 stored in authentication area 1303 with encrypted content 1307 stored in content storage directory 1306 in general area 1305 associated with the identifier 1317.
[0168] Meanwhile, the positive result obtained in step ST1403 means that memory card 1302 stores terminal identifier 1317 written by cellular phone 1301. In this case, encryption/decryption program 1312 shifts to step ST1405.
[0169] In step ST1405, encryption/decryption program 1312 acquires content 1315 from RAM 1314, shifts to step ST1406, and encrypts content 1315
acquired in step ST1404, for example, in the triple DES encryption scheme, using terminal identifier 1317 in ROM 1316.
[0170] Then, encryption/decryption program 1312 shifts to step ST1407, and stores encrypted content 1307 encrypted in step ST1406 in the directory associated by link information 1308 with terminal identifier 1317 stored in memory card 1302 in step ST1404.
[0171] In this way, as shown in FIG. 16, in memory card 1302, content 1315
(encrypted content 1307) encrypted using terminal identifier 1317 and terminal identifier 1317 is stored in association with one another via link information 1308. Thus, by associating encrypted content 1307 with terminal identifier 1317 via link information 1308, while storing terminal identifier 1317 to confirm the presence of encrypted content 1307 in authentication area 1303, it is made possible only for cellular phone 1301 accessible to authentication area 1303 to confirm the presence of encrypted content 1307.
[0172] FIG. 17 is a flowchart illustrating processing procedures of encryption/decryption program 1312 and content storage directory determination program 1313 when cellular phone 1301 reads and decodes encrypted content 1307 stored in memory card 1302 in the processing procedures in FIG. 15.
[0173] As shown in FIG. 17, in step ST1601, content storage directory determination program 1313 judges whether or not link information 1308 is present in general area 1305 in memory card 1302. The negative result obtained in this step means that link information 1308 is not stored in memory card 1302 i.e. encrypted content 1307 is not stored. In this case, content storage directory determination program 1313 finishes the processing procedures.
[0174] In contrast thereto, the positive result obtained in step ST1601
means that link information 1308 is stored in memory card 1302, i.e. encrypted content 1307 is present. In this case, content storage directory determination program 1313 shifts to step ST1602, performs authentication processing by authentication program 1309, and acquires terminal identifier 1317 corresponding to link information 1308 from authentication area 1308 in memory card 1302 using memory read program 108.
[0175] Then, content storage directory determination program 1313 shifts to step ST1603, compares the terminal identifier acquired in step ST1602
with terminal identifier 1317 stored in ROM 1316, and judges whether or not the acquired terminal identifier is the same as terminal identifier 1317 stored in ROM 1316.
[0176] When cellular phone 1301 encrypts content 1315 to write in memory card 1302, terminal identifier 1317 is always stored in association with encrypted content 1307. Accordingly, when the terminal identifier acquired in step ST1602 is in agreement with terminal identifier 1317
stored in ROM 1316 as a result of the comparison, it is meant that the terminal identifier acquired from memory card 1302 is written in memory card 1302 by cellular phone 1301, in other words, encrypted content 1307
stored in memory card 1302 in association with the terminal identifier 1317 via link information 1308 is written in memory card 1302 by cellular phone 1301.
[0177] Accordingly, when terminal identifier 1317 acquired from memory card 1302 in step ST1602 is in agreement with terminal identifier 1317
stored in ROM 1316 as a result of the comparison, content storage directory determination program 1313 notifies the result of agreement to encryption/decryption program 1312, and shifts from step ST1603 to step ST1604.
[0178] In contrast thereto, when the terminal identifier acquired from memory card 1302 in step ST1602 is not in agreement with terminal identifier 1317 stored in ROM 1316 as a result of the comparison, content storage directory determination program 1313 notifies the result of disagreement to encryption/decryption program 1312, returns to step ST1601, judges whether or not memory card 1302 has another link information 1308, and when another link information 1308 exists, executes the same processing on the link information 508.
[0179] In step ST1604, content storage directory determination program 1313 displays in list form on liquid crystal screen 116 the information of terminal identifier 1317 with the result of agreement in step ST1603, or information on encrypted content 1307 stored in directory 1306
associated with the terminal identifier 1317 through link information 1308.
[0180] In this way, liquid crystal screen 116 displays the information on encrypted content 1307 available in cellular phone 1301 among encrypted content stored in memory card 1302.
[0181] In addition, as a constitution for displaying in list form the information on encrypted content 1307 available in cellular phone 1301, for example, a method is considered of storing only limited information such as a title corresponding to encrypted content 1307 in RAM 1314 of cellular phone 1301 in storing the encrypted content 1307 in memory card 1302, and displaying in list form the stored limited information based on the result of agreement in step ST1603.
[0182] In step ST1604, when a list of content is displayed on liquid crystal screen 116, a user operates input interface 117, and thereby selects desired content from the displayed list.
[0183] By this means, encryption/decryption program 1312 shifts to step ST1605, reads encrypted content 1307 designated via input interface 117
from memory card 1302 using memory read program 108, shifts to a subsequent step ST1606, and decodes the encrypted content 1307 acquired from memory card 1302 in step ST1605, using terminal identifier 1317
stored in ROM 1316, to store in RAM 1314.
[0184] Content 1315 stored in RAM 1314 is initiated by the user of cellular phone 1301 operating input interface 117, and used by the user.
[0185] In the aforementioned constitution, when writing encrypted content 1307 in memory card 1302, cellular phone 1301 stores terminal identifier 1317 associated with the encrypted content 1307 in authentication area 1303 in memory card 1302.
[0186] The terminal identifier 1317 is, for example, a telephone number of cellular phone 1301, and thus has a data amount extremely smaller than that of encrypted content 1307. Accordingly, before reading encrypted content 1307 from memory card 1302 to decode, cellular telephone 1301
reads terminal identifier 1317 associated with the encrypted content 1307
from memory card 1302, and determines whether or not the terminal identifier 1317 is written in memory card 1302 by cellular phone 1301. It is thereby possible to readily judge whether or not content available in cellular phone 1301 is present in memory card 1302 based on terminal identifier 1317 with a small data amount.
[0187] In the case of this Embodiment, terminal identifier 1317 is stored in authentication area 1303, whereby access to authentication area 1303
in memory card 1302 from cellular phone 1301 is executed after carrying out the authentication processing. Accordingly, terminal apparatuses except cellular phone 1301 accessible to authentication area 1303 are hard to acquire terminal identifier 1317, and difficult to readily determine available encrypted content.
[0188] In this way, according to cellular phone 1301 as a content processing apparatus in this Embodiment, it is possible to more readily distinguish between a plurality of pieces of encrypted content stored in memory card 1302 that is a content storage medium only in cellular phone 1301 capable of performing authentication.
[0189] In addition, this Embodiment describes the case of storing terminal identifier 1317 stored in ROM 1316 of cellular phone 1301 in authentication area 1303 of memory card 1302 without encryption. However, the present invention is not limited to such a case, and terminal identifier 1317 may be encrypted and then stored in authentication area 1303 in memory card 1302.
[0190] Further, this Embodiment describes the case of storing terminal identifier 1317 stored in ROM 1316 of cellular phone 1301 in authentication area 1303 of memory card 1302 without any conversion. However, the present invention is not limited to such a case, and it may be possible that terminal identifier 1317 is converted using a predetermined conversion expression and stored in authentication area 1303, and cellular phone 1301 reads the converted terminal identifier from authentication 1303 to perform inverse conversion using an inverse conversion expression, and compares the inverse-converted identifier with terminal identifier 1317 in ROM 1316. In this case, as a conversion expression, various expressions may be used such as extracting a specific position (for example, lower four digits) of terminal identifier 1317, or rearranging a character sequence of terminal identifier 1317.
[0191] In addition, this Embodiment describes the case where a telephone number of cellular phone 1301 is used as terminal identifier 1317 in cellular phone 1301, but the present invention is not limited to such a case. For example, it may be possible to use an identifier for identifying cellular phone 1301 such as a serial number of cellular phone 1301, data such as a character sequence with some meaning, numeric value, image and audio, or an identifier (such as a membership number) indicating a contract with particular service. Further, as well as using as terminal identifier 1317 a telephone number, serial number or other information such as a character sequence without any processing, such a terminal identifier may be converted to be used (as information related to the terminal identifier). By this means, when an encryption method in encrypting content using the terminal identifier and/or the terminal identifier leaks to a third party, since the terminal identifier is converted into another data usable as an encryption key, it is possible to prevent interpretation of the encrypted content that is encrypted using the data (encryption key).
[0192] Further, this Embodiment describes the case of encrypting content 1315 using terminal identifier 1317 to store in memory card 1302, but the present invention is not limited to such a case. Content 1315 may be encrypted using information related to terminal identifier 1317.
[0193] Furthermore, this Embodiment describes the case of specifying a terminal identifier in the authentication area using link information stored in the general area, but the present invention is not limited to such a case. For example, information (such as a route name and directory name) indicating a storage location in the general area of the encrypted content stored in the general area may be made the same as information (such as a route name and directory name) indicating a storage location in the authentication area of the terminal identifier stored in the authentication area corresponding to the information on the identifier. By thus preparing the same directory structure, it is possible to associate the terminal identifier in the authentication area with the encrypted content in the general area without using link information.
[0194] Moreover, this Embodiment describes the case of using memory card 1302 as a content storage medium to store content, but the present invention is not limited to such a case. As long as a device is a content storage medium capable of storing digitalized information, other devices are widely applied.
Embodiment 5
[0195] FIG. 18 is a block diagram illustrating a configuration of cellular phone 1701 as a content processing apparatus according to Embodiment 5 of the present invention. In addition, the same sections as those in FIGS. 1
and 2 are assigned the same reference numerals as those in FIGS. 1 and 2, and specific descriptions thereof are omitted.
[0196] Cellular phone 1701 as shown in FIG. 18 differs from cellular phone 101 with the configuration as shown in FIG. 2 in the respect that as terminal identifiers stored in ROM 1713, there are prepared encryption terminal identifier 1714 to encrypt content 1712, and directory determination terminal identifier 1715 used as directory name 1704 of content storage directory (hereinafter, simply referred to as a directory) 1703 that stores encrypted content in memory card 1702.
[0197] FIG. 18 is a block diagram illustrating the configuration of cellular phone 1701 with the same reference numerals assigned to the same sections as in FIG. 2. FIG. 18 particularly shows a structure concerning content processing among the configuration of cellular phone 1701. Cellular phone 1701 includes memory write program 107, memory read program 108, and encryption/decryption program 1709 and content storage directory determination program 1710, each operated by a CPU (Central Processing Unit) not shown.
[0198] In FIG. 18, cellular phone 1701 stores content 1712 downloaded from a content provider via cellular phone networks in RAM (Random Access Memory) 1711. Encryption/decryption program 1709 is to encrypt content 1712 stored in RAM 1711. Content 1712 encrypted by encryption/decryption program 1709 is written in memory card 1702 by memory write program 107
via memory card interface 106, as encrypted content 1705.
[0199] ROM (Read Only Memory) 1713 stores encryption terminal identifier 1714 which is an identifier comprised of a predetermined character sequence (such as a serial number) unique to cellular phone 1701 and is used in encrypting content 1712, and directory determination terminal identifier 1715 which is an identifier comprised of a predetermined character sequence (such as a telephone number) unique to cellular phone 1701 and used as directory name 1704 in storing encrypted content in memory card 1702. Different character sequences are used for encryption terminal identifier 1714 and directory determination terminal identifier 1715.
[0200] Encryption/decryption program 1709 encrypts content 1712 using encryption terminal identifier 1714 stored in ROM (Read Only Memory) 1713. Further, when storing the content 1712 (encrypted content 1705) encrypted in memory card 1702, encryption/decryption program 1709 sets directory name 1704 of directory 1703 that is a storage destination as a terminal identifier name for directory determination terminal identifier 1715 stored in ROM 1713.
[0201] In the case where encrypted content 1705 stored in memory card 1702
is read into cellular phone 1701, memory read program 108 of cellular phone 1701 acquires directory name 1704 storing the encrypted content 1705 from memory card 1702, prior to the processing for reading the encrypted content 1705, and when the acquired directory name 1704 is in agreement with directory determination terminal identifier 1715 stored in ROM 1713, determines that the acquired directory name 1704 in memory card 1702 is set in memory card 1702 by cellular phone 1701.
[0202] Thus, when it is recognized that the directory name 1704 in memory card 1702 is set in memory card 1702 by cellular phone 1701, encryption/decryption program 1709 decodes encrypted content 1705 stored in directory 1703 with the directory name 1704, and stores the decoded content 1712 in RAM 1711.
[0203] FIG. 19 is a flowchart illustrating processing procedures of encryption/decryption program 1709 in storing in memory card 1702 content 1712 stored in RAM 1711 of cellular phone 1701.
[0204] As shown in FIG. 19, encryption/decryption program 1709 acquires directory determination terminal identifier 1715 from ROM 1713 in step ST1801. Then, encryption/decryption program 1709 shifts to step ST1802, and judges whether or not memory card 1702 has directory 1703 with directory name 1704 that is the same as the terminal identifier name of directory determination terminal identifier 1715 acquired in step ST1801.
[0205] The negative result obtained in this step means that memory card 1702 does not have directory 1703 set by cellular phone 1701. At this point, encryption/decryption program 1709 shifts to step ST1803, generates directory 1703 with directory name 1704 the same as the terminal identifier name of directory determination terminal identifier 1715 stored in ROM 1713, and shifts to step ST1804.
[0206] In contrast thereto, the positive result obtained in step ST1802
means that directory 1703 generated by cellular phone 1701 is already present in memory card 1702, and at this point, encryption/decryption program 1709 shifts to step ST1804.
[0207] After acquiring content 1712 from RAM 1711 in step ST1804, encryption/decryption program 1709 shifts to step ST1805, and encrypts the content 1712 acquired in step ST1804, for example, in the triple DES encryption scheme, using encryption terminal identifier 1714 in ROM 1713.
[0208] Then, encryption/decryption program 1709 shifts to step ST1806, and stores encrypted content 1705 encrypted in step ST1805 in directory 1703
with directory name 1704 generated in step ST1803.
[0209] In this way, as shown in FIG. 20, memory card 1702 stores content 1712 (encrypted content 1705) encrypted using encryption terminal identifier 1714, i.e. encrypted content 1705 written by a single cellular phone 1701 in directory 1703 with directory name 1704 the same as the terminal identifier name unique to the cellular phone.
[0210] FIG. 21 is a flowchart illustrating processing procedures of encryption/decryption program 1709 and content storage directory determination program 1710 when cellular phone 1701 reads encrypted content 1705 stored in memory card 1702 in the processing procedures in FIG. 19 to decode.
[0211] As shown in FIG. 21, in step ST2001, content storage directory determination program 1710 checks whether or not a directory is present in memory card 1702. The negative result obtained in this step means that memory card 1702 does not have encrypted content 1705 to read, and content storage directory determination program 1710 finishes the processing procedures.
[0212] In contrast thereto, the positive result obtained in step ST2001
means that memory card 1702 has encrypted content 1705 to read, and content storage directory determination program 1710 shifts to step ST2002, acquires a directory name from memory card 1702 using memory read program 108, and shifts to step ST2003. In step ST2003, content storage directory determination program 1710 judges whether or not the directory name acquired in step ST2002 is the same as that of directory determination terminal identifier 1715 stored in ROM 1713.
[0213] The negative result obtained in this step means that the directory name acquired from memory card 1702 is not directory name 1704 set by cellular phone 1701, i.e. that encrypted content stored in the directory of the name is not available in cellular phone 1701, and at this point, content storage directory determination program 1710 notifies the result of disagreement to encryption/decryption program 1709, returns to step ST2001, judges whether or not another directory is present in memory card 1702, and when another directory exists, executes the same processing on the directory.
[0214] In contrast thereto, the positive result obtained in step ST2003
means that the acquired directory is set by cellular phone 1701, i.e. that encrypted content 1705 stored in directory 1703 is available in cellular phone 1701, and at this point, content storage directory determination program 1710 notifies the result of agreement to encryption/decryption program 1709, and returns to step ST2004.
[0215] In step ST2004, content storage directory determination program 1710 displays in list form on liquid crystal screen 116 the information on directory name 1704 with the result of agreement in step ST2003, or information on encrypted content 1705 stored in directory 1703 with directory name 1704.
[0216] In this way, liquid crystal screen 116 displays the information on encrypted content 1705 available in cellular phone 1701 among encrypted content stored in memory card 1702.
[0217] In addition, as a constitution for displaying in list form the information on encrypted content 1705 available in cellular phone 1701, for example, a method is considered of storing only limited information such as a title corresponding to the encrypted content 1705 in RAM 1711
of cellular phone 1701 in storing the encrypted content 1705 in memory card 1702, and displaying in list form the stored limited information based on the result of agreement in step ST2004.
[0218] In step ST2004, when a list of content is displayed on liquid crystal screen 116, a user operates input interface 117, and thereby selects desired content from the displayed list.
[0219] By this means, encryption/decryption program 1709 shifts to step ST2005, reads encrypted content 1705 designated through input interface 117 from memory card 1702 using memory read program 108, shifts to a subsequent step, ST2006, and decodes the encrypted content 1705 acquired from memory card 1702 in step ST2005, using encryption terminal identifier 1714 stored in ROM 1713, to store in RAM 1711.
[0220] Content 1712 stored in RAM 1711 is initiated by the user of cellular phone 1701 operating input interface 117, and used by the user.
[0221] In the aforementioned constitution, cellular phone 1701 uses directory determination terminal identifier 1715 unique to cellular phone 1701 as directory name 1704 of a directory to store content 1705, in writing encrypted content 1705 in memory card 1702.
[0222] The directory name has a data amount extremely smaller than that of encrypted content 1705. Accordingly, before reading encrypted content 1705 from memory card 1702 to decode, cellular phone 1701 reads directory name 1704 of the directory storing the encrypted content 1705, and determines whether or not the directory name agrees with directory determination terminal identifier 1715 of cellular phone 1701.
[0223] When the directory name agrees with directory determination terminal identifier 1715 of cellular phone 1701, it is meant that encrypted content 1705 stored in the directory with directory name 1704
is written in memory card 1702 by cellular phone 1701.
[0224] Accordingly, it is possible to read the encrypted content 1705 into cellular phone 1701 to be used in cellular phone 1701, and encryption/decryption program 1709 reads the encrypted content 1705 from memory card 1702, and decodes the read encrypted content 1705.
[0225] Thus, on the condition that a directory name is in agreement with directory determination terminal identifier 1715 stored in ROM 1713, encrypted content 1705 stored in the directory with directory name 1704
is read into cellular phone 1701 from memory card 1702 to be decode, whereby cellular phone 1701 is capable of selecting only encrypted content 1705 available in cellular phone 1701 based on the directory name with a small data amount.
[0226] Accordingly, when a plurality of pieces of encrypted content is stored in memory card 1702 and terminal apparatuses (such as cellular telephones) capable of using the plurality of encrypted content vary with each encrypted content, cellular phone 1701 does not need to decode all the plurality of encrypted content with a large data amount, and only by acquiring a directory with a small data amount, is capable of determining available encrypted content 905.
[0227] Further, content 1712 is encrypted using encryption terminal identifier 1714 different from directory determination terminal identifier 1715 for use in directory name 1704, and is stored in the directory with directory name 1704 the same as directory determination terminal identifier 1715, whereby it is possible to prevent encrypted content 1705 from being decoded improperly even when directory name 1704
is known to a third party.
[0228] In this way, according to cellular phone 1701 as a content processing apparatus in this Embodiment, it is possible to more readily distinguish between a plurality of pieces of encrypted content stored in memory card 1702 that is a content storage medium, and more promptly decode encrypted content 1705 available in cellular phone 1701.
[0229] In addition, this Embodiment describes the case of using directory determination terminal identifier 1715 stored in ROM 1713 of cellular phone 1701 without encryption, as directory name 1704 to store encrypted content in memory card 1702. However, the present invention is not limited to such a case, and directory determination terminal identifier 1715 may be encrypted and used as a directory name.
[0230] Further, this Embodiment describes the case of using directory determination terminal identifier 1715 as directory name 1704 in memory card 1702 for storing encrypted content 1705. However, the present invention is not limited to such a case, and identification data 115 as described in FIG. 2 may be used.
[0231] In addition, this Embodiment describes the case where a telephone number, serial number and so on of cellular phone 1701 are used as encryption terminal identifier 1714 and directory determination terminal identifier 1715 in cellular phone 1701, but the present invention is not limited to such a case. For example, it may be possible to use data such as a character sequence with some meaning, numeric value, image and audio, or an identifier (such as a membership number) indicating a contract with particular service. Further, as well as using as encryption terminal identifier 1714 and directory determination terminal identifier 1715 a telephone number, serial number or other information such as a character sequence without any processing, such terminal identifiers (encryption terminal identifier 1714 and directory determination terminal identifier 1715) may be converted to be used (as information related to the terminal identifier). By this means, when an encryption method in encrypting content using the terminal identifier and/or the terminal identifier leaks to a third party, since the terminal identifier is converted into another data usable as an encryption key, it is possible to prevent interpretation of the encrypted content that is encrypted using the data (encryption key).
[0232] Further, this Embodiment describes the case of encrypting content 1712 using encryption terminal identifier 1714 to store in memory card 1702, but the present invention is not limited to such a case. Content 1712 may be encrypted using information related to encryption terminal identifier 1714.
[0233] Furthermore, this Embodiment describes the case of using memory card 1702 as a content storage medium to store content, but the present invention is not limited to such a case. As long as a device is a content storage medium capable of storing digitalized information, other devices are widely applied.
Embodiment 6
[0234] FIG. 22 is a block diagram illustrating a configuration of cellular phone 2101 as a content processing apparatus according to Embodiment 6 of the present invention. In addition, the same sections as those in FIGS. 1
and 2 are assigned the same reference numerals as those in FIGS. 1 and 2, and specific descriptions thereof are omitted.
[0235] Cellular telephone 2101 as shown in FIG. 22 differs from cellular phone 101 with the configuration as shown in FIG. 2 in the respect that write time is written in association with encrypted content 2105, instead of identification data 115 as described in FIG. 2, in writing content 2112 stored in RAM 2111 in memory card 2102.
[0236] FIG. 22 is a block diagram illustrating the configuration of cellular phone 2101 with the same reference numerals assigned to the same sections as in FIG. 2. FIG. 22 particularly shows a structure concerning content processing among the configuration of cellular phone 2101. Cellular phone 2101 includes memory write program 107, memory read program 108, encryption/decryption program 2109, content storage directory determination program 2110 and time specification program 2119, each operated by a CPU (Central Processing Unit) not shown.
[0237] In FIG. 22, cellular phone 2101 stores content 2112 downloaded from a content provider via cellular phone networks in RAM (Random Access Memory) 2111. Encryption/decryption program 2109 is to encrypt content 2112 stored in RAM 2111. Content 2112 encrypted by encryption/decryption program 2109 is written in memory card 2102 as encrypted content 2105 by memory write program 107 via memory card interface 106.
[0238] ROM (Read Only Memory) 2114 stores terminal identifier 2115 which is comprised of a predetermined character sequence (such as a telephone number) unique to cellular phone 2101 and which is used in encrypting content 2112.
[0239] Encryption/decryption program 2109 encrypts content 2112 using terminal identifier 2115 stored in ROM (Read Only Memory) 2114. Further, when storing content 2112 (encrypted content 2105) encrypted in memory card 2102, encryption/decryption program 2109 stores write time information 2113 indicative of write time specified by time specification program 2119 in the same directory as that storing encrypted content 2105
in memory card 2102. Thus, encrypted content 2105 and write time information 2113 is stored in memory card 2102 in association with each other. Further, write time information 2113 stored in memory card 2102 is also stored in RAM 2111 of cellular phone 2101 by encryption/decryption program 2109 and time specification program 2119.
[0240] When encrypted content 2105 stored in the predetermined directory, 2103, in memory card 2102 is read into cellular phone 2101, memory read program 108 of cellular phone 2101 adds to list information encrypted content 2105 stored in memory card 2102 in association with write time information 2113 in agreement with write time information 2113 stored in RAM 2111 of cellular phone 2101, prior to the processing for reading encrypted content 2105. It is determined that encrypted content 2105
described in the list is written in memory card 2102 by cellular phone 2101.
[0241] Thus, when it is recognized that write time information 2113 stored in memory card 2102 is stored in memory card 2101 by cellular phone 2101, encryption/decryption program 2109 decodes encrypted content 2105 stored in association with write time information 2113, and stores the decoded content 2112 in RAM 2111.
[0242] FIG. 23 is a flowchart illustrating processing procedures of encryption/decryption program 2109 and time specification program 2119 in storing in memory card 2102 content 2112 stored in RAM 2111 of cellular phone 2101.
[0243] As shown in FIG. 23, in step ST2201, encryption/decryption program 2109 generates directory 2103 to store content, shifts to a subsequent step, ST2202, and acquires content 2112 from RAM 2111. Then, encryption/decryption program 2109 shifts to step ST2203, and encrypts the content 2112 acquired in step ST2202, for example, in the triple DES (Data encryption Standard) encryption scheme, using terminal identifier 2115 in ROM 2114.
[0244] Encryption/decryption program 2109 shifts to step ST2204, and generates time information of this time using time specification program 2119 to store in RAM 2111 as write time information 2113. In this way, RAM 2111 stores write time information 2113 indicating the time encrypted content 2105 was written in memory card 2102.
[0245] Then, encryption/decryption program 2109 shifts to step ST2205, and stores encrypted content 2105 encrypted in step ST2203 in directory 2103
in memory card 2102 generated in step ST2201, together with write time information 2113 generated in step ST2204.
[0246] In this way, as shown in FIG. 24, in memory card 2102, encrypted content 2105 and write time information 2113 indicative of the time the content 2105 was written in memory card 2102 is stored in the same directory, 2103, in association with each other.
[0247] FIG. 25 is a flowchart illustrating processing procedures of encryption/decryption program 2109 and content storage directory determination program 2110 when cellular phone 2101 reads and decodes encrypted content 2105 stored in memory card 2102 in the processing procedures in FIG. 23.
[0248] As shown in FIG. 25, in step ST2401, content storage directory determination program 2110 checks whether or not encrypted content is present in memory card 2102. The positive result obtained in this step means a possibility that encrypted content written in memory card 2102 by cellular phone 2102 i.e. encrypted content 2105 available for cellular phone 2101 is stored in memory card 2102, and at this point, content storage directory determination program 2110 shifts to step ST2402, and acquires write time information existing in the same directory as that of the encrypted content.
[0249] Then, content storage directory determination program 2110 shifts to step ST2403, and judges whether the write time information acquired in step ST2402 is the same as write time information 2113 stored in RAM 2111
of cellular phone 2101.
[0250] The negative result obtained in this step means that the acquired write time information is not written in memory card 2102 by cellular phone 2101, i.e. the encrypted content stored in directory the same as that of the write time information is not written in memory card 2102 by cellular phone 2101. At this point, content storage directory determination program 2110 returns to step ST2401, judges whether or not another encrypted content is stored in memory card 2102, and based on a result of judgment, executes the same processing as described above.
[0251] In contrast thereto, the positive result obtained in step ST2403
means that the acquired write time information is write time information 2113 written in memory card 2102 by cellular phone 2101, i.e. encrypted content 2105 stored in directory 2103 the same as that of the write time information 2113 is written in memory card 2102 by cellular phone 2101. At this point, content storage directory determination program 2110
shifts to step ST2404, adds the write time information 2113 to the list information, returns to step ST2401, judges whether or not another encrypted content is stored in memory card 2102, and based on a result of judgment, executes the same processing as described above.
[0252] When the judgment of whether or not encrypted content is written by cellular phone 2101 is made on all the encrypted content (write time information) stored in memory card 2102, content storage directory determination program 2110 obtains the negative result in step ST2401, shifts to step ST2405, and displays in list form on liquid crystal screen 116 the information on encrypted content 2105 specified by the list information generated in step ST2404.
[0253] In this way, liquid crystal screen 116 displays in list form the information (such as write time information) related to encrypted content 2105 available in cellular phone 2101 among encrypted content stored in memory card 2102.
[0254] In addition, as a constitution for displaying in list form the information related to encrypted content 2105 available in cellular phone 2101, for example, a method is considered of storing only limited information such as a title corresponding to encrypted content 2105 in RAM 2111 of cellular phone 2101 in storing the encrypted content 2105 in memory card 2102, and displaying in list form the stored limited information based on the result of agreement in step ST2403.
[0255] In step ST2405, when a list of content is displayed on liquid crystal screen 116, a user operates input interface 117, and thereby selects desired content from the displayed list.
[