Information recording apparatus, information reproducing apparatus, and information distribution system

[0001] The present invention relates to an information recording apparatus for recording information on a recording medium such as a DVD, an information reproducing apparatus for reproducing information recorded on a recording medium such as a DVD, and an information distribution system including an information recording/reproducing apparatus for charging for use of information recorded on a recording medium or distributed through a network or by broadcasting.

[0002] In recent years, the advance of digital information processing technology and communication technology such as a broadband ISDN, and the development of an advanced information recording medium such as a DVD which realizes a large capacity and high-quality image and sound are progressing. Along with such development of a variety of advanced information transmission means, the circumstances are allowing users to make use of an enormous number of digitized works which are distributed to the users through a network, a recording medium, or the like. These circumstances increase opportunities for copies and alterations without permission of authors or distribution unintended by authors, so copyright holders are anxious about infringement on their benefits.

[0003] An important challenge for wiping out such anxiety of copyright holders is the development of a system which allows quick and easy distribution of digitized works and provides a fair digital information usage environment assuming protection by copyright.

[0004] A DVD is a large-capacity personal computer medium replacing a CD-ROM, and various applications to movie, music, game, karaoke, and the like can be expected. For popularization of DVDs, inexpensive DVD titles or spread of a rental DVD market is expected. From these viewpoints as well, it is essential to provide an information distribution system assuming protection by copyright of information, i.e., a system based on a concept of charging not for possession of a digitized work recorded on a recording medium such as a DVD but for use of the digitized work.

[0005] It is an object of the present invention to provide an information recording apparatus, an information reproducing apparatus, and an accounting apparatus to constitute an information distribution system which allows quick and easy distribution of digitized works and provides a digital information usage environment assuming protection by copyright.

[0006] It is another object of the present invention to provide an information recording apparatus for quickly and easily distributing digitized works which are distributed through a network or a recording medium and constituting a digital information usage environment assuming protection by copyright by charging for use of digital information, an apparatus for reproducing the recorded information, and an accounting apparatus for charging for use of information.

[0007] According to an aspect of the present invention, there is provided an information recording apparatus comprising an encryption section for encrypting contents information, a license information generator for encrypting at least a license condition referred to limit use of the contents information and a decoding key for decoding the encrypted contents information to generate license information, and a recording section for recording the contents information encrypted by the encryption section and the license information generated by the license information generator on a recording medium.

[0008] According to another aspect of the present invention, there is provided an information reproducing apparatus comprising a storage section for storing second decoding key information for decoding license information, a first decoder section for decoding the license information recorded on the recording medium using the second decoding key stored in the storage section, a decision section for deciding, on the basis of a license condition contained in the license information decoded by the first decoder section, whether contents information can be used, a second decoder section for decoding the encrypted contents information recorded on the recording medium using the first decoding key contained in the license information decoded by the first decoder section when the decision section decides that the contents information can be used, and a reproduction section for reproducing the contents information decoded by the second decoder section.

[0009] According to the information recording apparatus of the present invention, the encrypted contents information and the license condition of the contents information are inseparately recorded on the recording medium. Only the information reproducing apparatus having an authentic decoding key for decoding the license information can reproduce the contents information recorded on the recording medium. In addition, since, before decoding, it is always decided on the basis of the license condition contained in the license information whether the contents information can be used, use of the contents information under an illicit use condition is disabled. Therefore, digital information assuming protection by copyright of the contents information can be quickly and easily distributed.

[0010] According to still another aspect of the present invention, there is provided an accounting apparatus for charging for use of contents information recorded on a recording medium, comprising an input section for inputting a desired condition for use of the contents information recorded on the recording medium, a fee claiming section for claiming a fee for use of the contents information on the basis of the condition input by the input section, and a recording section for, upon confirming fee payment in response to the claim, recording, on the recording medium, license information containing at least a license condition for limiting use of the contents information recorded on the recording medium on the basis of the condition input by the input section. With this arrangement, for the recording medium on which the contents information and the license information containing the license condition for limiting use of the contents information are recorded, appropriate charging for use of the contents information is enabled. In addition, digital information assuming protection by copyright of the contents information can be quickly and easily distributed.

[0011] According to still another aspect of the present invention, there is provided an accounting apparatus for charging for use of contents information through a recording medium on which contents information and encrypted license information containing at least a license condition referred to to limit the use of the contents information are recorded, comprising a license information input section for inputting the encrypted license information recorded on the recording medium, a decoder section for decoding the encrypted license information input by the license information input section, a condition acceptance section for accepting a desired condition for use of the contents information, a fee claiming section for claiming a fee for use of the contents information on the basis of the condition accepted by the condition acceptance section, a license information update section for, upon confirming fee payment in response to the claim, updating the license information decoded by the decoder section, on the basis of the condition input by the condition input section, an encryption section for encrypting the license information updated by the license information update section, and an output section for outputting the license information encrypted by the encryption section. With this arrangement, for the recording medium on which the contents information and the license information containing the license condition for limiting use of the contents information are recorded, appropriate charging for use of the contents information is enabled. In addition, digital information assuming protection by copyright of the contents information can be quickly and easily distributed.

[0012] According to still another aspect of the present invention, there is provided a decision apparatus for deciding, on the basis of encrypted license information containing at least a license condition referred to to limit use of contents information and key information for decoding the contents information, whether the contents information can be used, comprising a key generator for generating a public key used to encrypt the license information and a secret key for decoding the license information at a predetermined timing, the secret key corresponding to the public key, a decoder section for decoding the input license information using the secret key generated by the key generator, a decision section for deciding, on the basis of the license condition contained in the license information decoded by the decoder section, whether the contents information can be decoded, and an output section for outputting key information contained in the license information decoded by the decoder section when the decision section decides that the contents information can be used.

[0013] According to the present invention, since the secret parameter for decoding the license information is generated in a decoder unit A at a predetermined timing and used only within a predetermined period, information security for the license information containing the license condition of the contents information and contents information decoding key can be improved.

[0014] According to an update apparatus of the present invention, which updates license information on the basis of a request for updating the license information upon receiving at least a newly designated license condition and second key generation information necessary for generating second key information from a decision device for deciding, on the basis of encrypted license information containing at least a license condition referred to to limit use of contents information, encrypted first key information for decoding the contents information, and first key generation information necessary for generating the second key information for decoding the encrypted first key information, whether the contents information can be used, the license condition and the first key generation information are updated, the second key information is updated on the basis of the updated first key generation information and the second key generation information, and the first key information is encrypted using the updated second key information to generate encrypted license information containing at least the updated license condition, the first key information encrypted using the updated second key information, and the updated first key generation information.

[0015] According to the present invention, when the license information is to be updated, the license information can be updated while ensuring the information security without supplying the contents decoding key.

[0016] According to an update apparatus of the present invention, which updates license information on the basis of a request for updating the license information upon receiving at least a newly designated license condition, second key generation information necessary for generating second key information, and an updated public key from a decision device for deciding, on the basis of the license information containing at least a license condition referred to to limit use of contents information, encrypted first key information for decoding the contents information, and first key generation information necessary for generating the second key information for decoding the encrypted first key information, whether the contents information can be used, the license information being encrypted using a public key, the license condition and the first key generation information are updated, the second key information is updated on the basis of the updated first key generation information and the second key generation information, and the first key information is encrypted using the updated second key information to generate license information containing at least the updated license condition, the first key information encrypted using the updated second key information, and the updated first key generation information, and the generated license information is encrypted using the supplied public key.

[0017] According to the present invention, when the license information is to be updated, the license information can be updated while ensuring the information security without supplying the contents decoding key.

[0018] According to the present invention, there is provided an information usage apparatus which receives encrypted first key information for decoding encrypted contents information and first key generation information necessary for generating second key information for decoding the first key information and decodes and uses the contents information, wherein second key generation information necessary for generating the second key information for decoding the first key information is held, the second key information is generated on the basis of the second key generation information and the input first key generation information, and the encrypted contents information is decoded using the generated second key information.

[0019] According to the present invention, since the decoding key (first key information) of the contents information is input to the information usage apparatus while being kept encrypted, the information security between the device for outputting the first key information and the information usage apparatus can be improved.

[0020] According to still another aspect of the present invention, there is provided an information reproducing apparatus for reproducing contents information from a recording medium on which encrypted contents information and license information containing at least a license condition referred to to limit use of the contents information and first key information for decoding the contents information are recorded, comprising an instrument section for measuring a date and time, a decision section for deciding, on the basis of the date and time measured by the instrument section and the license information recorded on the recording medium, whether the contents information can be used, and an information reproduction section for, when the decision section decides that the contents information can be used, decoding and reproducing the contents information recorded on the recording medium using the first key information output from the decision section, wherein information for notifying the decision section of the date and time from the instrument section and the first key information output from the decision section to the information reproduction section are encrypted.

[0021] According to the present invention, the security of information to be transferred among the functional units (the instrument section, the decision section, and the information reproduction section) in the information generation device can be improved.

[0022] According to still another aspect of the present invention, there is provided an information recording method of recording, on a recording medium on which at least encrypted contents information is recorded, encrypted license information containing at least a license condition referred to to limit use of the contents information and a decoding key of the contents information, comprising transmitting information for designating second key information for encrypting first key information for encrypting the license information to a decision device for deciding whether the contents information can be used, receiving, from the portable recording medium, the first key information for encrypting the license information, which is encrypted using the designated second key information, and recording, on the recording medium, license information generated on the basis of a designated license condition and encrypted using the first key information.

[0023] According to the present invention, the contents information recorded on the recording medium cannot be normally decoded unless the decision device which has been used to record the license information in the recording medium is not used. Therefore, illicit use of the contents information can be prevented.

[0024] Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinbefore.

[0025] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments give below, serve to explain the principles of the invention.

[0026] FIG. 1 is a block diagram showing the first arrangement of an information recording apparatus according to the first embodiment of the present invention;

[0027] FIG. 2 is a flow chart for explaining the operation of the first information recording apparatus shown in FIG. 1;

[0028] FIG. 3 is a block diagram showing the second arrangement of the information recording apparatus according to the first embodiment of the present invention;

[0029] FIG. 4 is a flow chart for explaining the operation of the second information recording apparatus shown in FIG. 3;

[0030] FIGS. 5A and 5B are views for explaining a method of separating accounting object information;

[0031] FIGS. 6A and 6B are views for explaining another method of separating accounting object information;

[0032] FIG. 7 is a block diagram showing the third arrangement of the information recording apparatus according to the first embodiment of the present invention;

[0033] FIG. 8 is a block diagram showing the first arrangement of an information reproducing apparatus according to the first embodiment of the present invention;

[0034] FIG. 9 is a block diagram showing an arrangement of a decoder unit shown in FIG. 8;

[0035] FIG. 10 is a flow chart for explaining the operation of the first information reproducing apparatus shown in FIG. 8;

[0036] FIG. 11 is a flow chart for explaining the operation of the decoder unit shown in FIG. 9;

[0037] FIG. 12 is a block diagram showing another arrangement of the decoder unit having a clock for disabling time update;

[0038] FIG. 13 is a flow chart for explaining the operation of the clock of the decoder unit, which disables time update;

[0039] FIG. 14 is a flow chart for explaining the operation of the decoder unit shown in FIG. 12;

[0040] FIG. 15 is a block diagram showing an arrangement of the clock of the decoder unit capable of updating time;

[0041] FIG. 16 is a flow chart for explaining the time update operation of the clock shown in FIG. 15;

[0042] FIG. 17 is a view showing a system constituted by a client and a server to update time of the clock of the decoder unit through a network;

[0043] FIG. 18 is a block diagram showing an arrangement of a time setting client shown in FIG. 17;

[0044] FIG. 19 is a block diagram showing an arrangement of a time setting server shown in FIG. 17;

[0045] FIG. 20 is a flow chart for explaining the operation of the time setting client shown in FIG. 18;

[0046] FIG. 21 is a flow chart for explaining the operation of the time setting server shown in FIG. 19;

[0047] FIG. 22 is a flow chart for explaining the operation of the time setting server shown in FIG. 19;

[0048] FIG. 23 is a block diagram showing an arrangement of a clock incorporated in the timesetting client shown in FIG. 18;

[0049] FIG. 24 is a flow chart for explaining the operation of the clock shown in FIG. 23;

[0050] FIG. 25 is a flow chart for explaining the operation of the clock shown in FIG. 23;

[0051] FIG. 26 is a block diagram showing an arrangement of an information reproducing apparatus (second information reproducing apparatus) having a function of updating license information and performing charging;

[0052] FIG. 27 is a block diagram showing an arrangement of a decoder unit shown in FIG. 26;

[0053] FIG. 28 is a flow chart for explaining the operation of the decoder unit shown in FIG. 27;

[0054] FIG. 29 is a block diagram showing an arrangement of a license information update client section shown in FIG. 26;

[0055] FIG. 30 is a flow chart for explaining the operation of the license information update client section shown in FIG. 29;

[0056] FIG. 31 is a block diagram showing an arrangement of a license information update server shown in FIG. 26;

[0057] FIG. 32 is a flow chart for explaining the operation of the license information update server shown in FIG. 31;

[0058] FIG. 33 is a view showing an example of contents of fee claiming for use of accounting object information output from the license information update server;

[0059] FIG. 34 is a flow chart for explaining the operation of the entire system (the server and the client communicating with each other through the network) shown in FIG. 26;

[0060] FIG. 35 is a block diagram showing an arrangement of a license information update unit;

[0061] FIG. 36 is a flow chart for explaining the operation of the license information update unit shown in FIG. 35;

[0062] FIG. 37 is a flow chart for explaining the operation of the license information update unit shown in FIG. 35;

[0063] FIG. 38 is a block diagram showing an arrangement of an accounting apparatus for charging for use of accounting object information;

[0064] FIG. 39 is a block diagram showing an arrangement of a decoder unit in an information reproducing apparatus with a measure for an illicit copy of accounting object information (decision is made on the basis of a decoder unit ID);

[0065] FIG. 40 is a flow chart for explaining the operation of the decoder unit shown in FIG. 39;

[0066] FIG. 41 is a block diagram showing an arrangement of a license information update unit with a measure for an illicit copy of accounting object information;

[0067] FIG. 42 is a flow chart for explaining the operation of the license information update unit shown in FIG. 41;

[0068] FIG. 43 is a block diagram showing another arrangement of the decoder unit with a measure for an illicit copy of accounting object information (decision is made on the basis of a decoder unit ID and medium ID);

[0069] FIG. 44 is a flow chart for explaining the operation of the decoder unit shown in FIG. 43;

[0070] FIG. 45 is a block diagram showing an arrangement of a copying apparatus;

[0071] FIG. 46 is a flow chart for explaining the operation of the copying apparatus shown in FIG. 45;

[0072] FIG. 47 is a block diagram showing an arrangement of a license information copy unit shown in FIG. 45;

[0073] FIG. 48 is a flow chart for explaining the operation of the license information copy unit shown in FIG. 47;

[0074] FIG. 49 is a block diagram showing an arrangement of an information reproducing apparatus (third information reproducing apparatus) according to the first embodiment of the present invention, which reproduces subsidiary information;

[0075] FIG. 50 is a block diagram showing an arrangement of the third information reproducing apparatus shown in FIG. 49;

[0076] FIG. 51 is a block diagram showing an arrangement of a decoder unit shown in FIG. 49;

[0077] FIG. 52 is a flow chart for explaining the operation of the decoder unit shown in FIG. 51;

[0078] FIG. 53 is a block diagram showing an arrangement of an information distribution system using the information recording apparatus and information reproducing apparatus of the present invention;

[0079] FIG. 54 is a block diagram showing an arrangement of a decoder unit A according to the second embodiment of the present invention;

[0080] FIG. 55 is a view showing an example of license information input to the decoder unit A;

[0081] FIG. 56 is a view showing an example of updated information output from the decoder unit A;

[0082] FIG. 57 is a flow chart for explaining the processing operation of the decoder unit A;

[0083] FIG. 58 is a flow chart for explaining the schematic procedure of key generation processing in a key holder section and key generation section of the decoder unit A;

[0084] FIG. 59 is a block diagram showing an arrangement of a decoder unit B;

[0085] FIG. 60 is a view showing an example of license information input to the decoder unit B;

[0086] FIG. 61 is a flow chart for explaining the processing operation of the decoder unit B;

[0087] FIG. 62 is a view showing an example of updated information output from the decoder unit B;

[0088] FIG. 63 is a block diagram showing an arrangement of a decoder unit C;

[0089] FIG. 64 is a view showing an example of updated information output from the decoder unit C;

[0090] FIG. 65 is a block diagram showing an arrangement of a decoder unit D;

[0091] FIG. 66 is a view showing an example of license information input to the decoder unit D;

[0092] FIG. 67 is a flow chart for explaining the processing operation of the decoder unit D;

[0093] FIG. 68 is a flow chart for explaining the processing operation of the decoder unit D;

[0094] FIG. 69 is a view showing an example of updated information output from the decoder unit D;

[0095] FIG. 70 is a block diagram showing an arrangement of a decoder unit D;

[0096] FIG. 71 is a block diagram showing an arrangement of a license information update apparatus corresponding to the decoder unit A;

[0097] FIG. 72 is a flow chart for explaining the processing operation of the license information update apparatus shown in FIG. 71;

[0098] FIG. 73 is a block diagram showing an arrangement of a license information update apparatus corresponding to the decoder unit B;

[0099] FIG. 74 is a flow chart for explaining the processing operation of the license information update apparatus shown in FIG. 73;

[0100] FIG. 75 is a block diagram showing an arrangement of an information distribution system according to the third embodiment;

[0101] FIG. 76 is a block diagram showing another arrangement of the information distribution system according to the third embodiment;

[0102] FIG. 77 is a block diagram showing an arrangement of the main part of an information reproducing apparatus in which a decoding decision card is mounted;

[0103] FIG. 78 is a flow chart for explaining the processing operation of the information reproducing apparatus shown in FIG. 77 which is used in the information distribution system shown in FIG. 75;

[0104] FIG. 79 is a block diagram showing an arrangement of the main part of the decoding decision card;

[0105] FIG. 80 is a flow chart for explaining the processing operation of the decoding decision card shown in FIG. 79;

[0106] FIG. 81 is a block diagram showing an arrangement of a time transfer section in the decoding decision card shown in FIG. 79;

[0107] FIG. 82 is a block diagram showing an arrangement of a certification section in the time transfer section shown in FIG. 81;

[0108] FIG. 83 is a flow chart for explaining the processing operation of the certification section shown in FIG. 82;

[0109] FIG. 84 is a block diagram showing an arrangement of a contents key transfer section in the decoding decision card shown in FIG. 79;

[0110] FIG. 85 is a block diagram showing an arrangement of a certification section in the contents key transfer section shown in FIG. 84;

[0111] FIG. 86 is a flow chart for explaining the processing operation of the certification section shown in FIG. 85;

[0112] FIG. 87 is a block diagram showing an arrangement of a clock shown in FIG. 77;

[0113] FIG. 88 is a block diagram showing an arrangement of a certification section in the clock shown in FIG. 87;

[0114] FIG. 89 is a flow chart for explaining the processing operation of the certification section shown in FIG. 88;

[0115] FIG. 90 is a block diagram showing an arrangement of a decoding decision section shown in FIG. 79;

[0116] FIG. 91 is a flow chart for explaining the processing operation of the decoding decision section shown in FIG. 90;

[0117] FIG. 92 is a block diagram showing an arrangement of an information reproduction section shown in FIG. 77;

[0118] FIG. 93 is a flow chart for explaining the processing operation of the information reproduction section shown in FIG. 92;

[0119] FIG. 94 is a block diagram showing an arrangement of a certification section in the information reproduction section shown in FIG. 92;

[0120] FIG. 95 is a flow chart for explaining the processing operation of the certification section shown in FIG. 94;

[0121] FIG. 96 is a block diagram showing another arrangement of the information reproduction section shown in FIG. 77;

[0122] FIG. 97 is a block diagram showing an arrangement of a license update apparatus;

[0123] FIG. 98 is a flow chart for explaining the processing operation of the license update apparatus;

[0124] FIG. 99 is a block diagram showing an arrangement of the main part of a decoding decision card as an interface with the update IF of the license update apparatus;

[0125] FIG. 100 is a flow chart for explaining the processing operation of the decoding decision card in updating the license;

[0126] FIG. 101 is a block diagram showing an arrangement of a license server;

[0127] FIG. 102 is a flow chart for explaining the processing operation of the license server;

[0128] FIG. 103 is a block diagram showing a system configuration constituted by a user terminal, a license server, and an electronic banking apparatus in updating the license using electronic banking;

[0129] FIG. 104 is a block diagram showing an arrangement of a license update apparatus in the system configuration shown in FIG. 103;

[0130] FIG. 105 is a block diagram showing an arrangement of the license server in the system configuration shown in FIG. 103;

[0131] FIG. 106 is a flow chart for explaining the processing operation of the entire system in updating the license in the system configuration shown in FIG. 103;

[0132] FIG. 107 is a block diagram showing an entire arrangement of an information reproduction system according to the fourth embodiment of the present invention;

[0133] FIG. 108 is a block diagram showing an arrangement of a license decision unit shown in FIG. 107;

[0134] FIG. 109 is a flow chart for explaining the processing operation of the information reproducing apparatus shown in FIG. 107;

[0135] FIG. 110 is a flow chart for explaining the processing operation of the information reproducing apparatus shown in FIG. 107;

[0136] FIG. 111 is a flow chart for explaining the processing operation of the information reproducing apparatus shown in FIG. 107 until license information is stored in a license database;

[0137] FIG. 112 is a flow chart for explaining the license information decoding key generation processing of the information reproducing apparatus shown in FIG. 107;

[0138] FIG. 113 is a view showing a structure of contents information;

[0139] FIG. 114 is a view showing a structure of license information;

[0140] FIG. 115 is a view showing an example of storage of license information in a license information database;

[0141] FIG. 116 is a view showing a structure of license update information;

[0142] FIG. 117 is a view showing another example of storage of license information in the license information database;

[0143] FIG. 118 is a block diagram showing another arrangement of the information reproducing apparatus shown in FIG. 107;

[0144] FIG. 119 is a block diagram showing another arrangement of the license decision unit shown in FIG. 107;

[0145] FIG. 120 is a flow chart for explaining the operation of the information reproducing apparatus shown in FIG. 118 until encrypted license information and decoding key seed information are separated from a received broadcasting wave to generate a decoding key;

[0146] FIG. 121 is a view showing an example of the data structure of a broadcasting wave;

[0147] FIG. 122 is a block diagram showing an arrangement of an information distribution system according to the fifth embodiment of the present invention;

[0148] FIG. 123 is a view showing an example of data recorded on a rental disk;

[0149] FIG. 124 is a view showing an example of storage of a disk key in a contents database prepared in a center;

[0150] FIG. 125 is a view schematically showing the disk key distribution scheme in the information distribution system shown in FIG. 122;

[0151] FIG. 126 is a block diagram showing an arrangement of a license creation device;

[0152] FIG. 127 is a block diagram showing an arrangement of a license issuing device;

[0153] FIG. 128 is a block diagram showing an arrangement of a card;

[0154] FIG. 129 is a block diagram showing an arrangement of a card adapter;

[0155] FIG. 130 is a block diagram showing an arrangement of a player;

[0156] FIG. 131 is a flow chart for explaining the disk information creation processing of the license creation device;

[0157] FIG. 132 is a view showing an example of storage of disk information in a license database in the license issuing device;

[0158] FIG. 133 is a view showing the schematic sequence of a disk key distribution procedure in the information distribution system shown in FIG. 122 about subscription to a disk rental service, rental of a disk, and reproduction of contents;

[0159] FIG. 134 is a flow chart showing the disk key distribution procedure shown in FIG. 133 in more detail;

[0160] FIG. 135 is a flow chart showing the disk key distribution procedure shown in FIG. 133 in more detail;

[0161] FIG. 136 is a flow chart showing the disk key distribution procedure shown in FIG. 133 in more detail;

[0162] FIG. 137 is a flow chart showing the disk key distribution procedure shown in FIG. 133 in more detail;

[0163] FIG. 138 is a flow chart showing the disk key distribution procedure shown in FIG. 133 in more detail;

[0164] FIG. 139 is a flow chart showing the disk key distribution procedure shown in FIG. 133 in more detail;

[0165] FIG. 140 is a flow chart showing the disk key distribution procedure shown in FIG. 133 in more detail;

[0166] FIG. 141 is a view showing the schematic sequence of another disk key distribution procedure in the information distribution system shown in FIG. 122 about subscription to a disk rental service, rental of a disk, and reproduction of contents;

[0167] FIG. 142 is a flow chart showing the disk key distribution procedure shown in FIG. 141 in more detail;

[0168] FIG. 143 is a flow chart showing the disk key distribution procedure shown in FIG. 141 in more detail;

[0169] FIG. 144 is a flow chart showing the disk key distribution procedure shown in FIG. 141 in more detail;

[0170] FIG. 145 is a flow chart showing the disk key distribution procedure shown in FIG. 141 in more detail:

[0171] FIG. 146 is a flow chart showing the disk key distribution procedure shown in FIG. 141 in more detail;

[0172] FIG. 147 is a flow chart for explaining encryption parameter update processing;

[0173] FIG. 148 is a flow chart for explaining encryption parameter update processing; and

[0174] FIG. 149 is a flow chart for explaining encryption parameter update processing.

[0175] Embodiments of the present invention will be described below with reference to the accompanying drawing.

[0176] The entire configuration of an information distribution system using an information recording apparatus and information reproducing apparatus according to the first embodiment of the present invention will be briefly described first.

[0177] FIG. 53 shows an arrangement of an information distribution system using the information recording apparatus and information reproducing apparatus of the present invention. Referring to FIG. 53, a license information generation section 1002 and an information storage section 1003 are equivalent to those shown in FIGS. 1, 3, 7, or the like, and a decoder unit 1013 is equivalent to that shown in FIGS. 9, 12, 27, 39, 43, or the like. A reproduction section 1014 and a readout section 1012 are also equivalent to those in the information reproducing apparatus shown in FIG. 8 or the like.

[0178] The operation of the entire system shown in FIG. 53 will be briefly described below. Accounting object information is encrypted by an encryption key ke(1) (accounting object information ke(1)). First, a decoding key kd(1) of the accounting object information and a license condition such as an expiration date are input to the license information generation section 1002 (steps S701 and S702).

[0179] The license information generation section 1002 merges the decoding key kd(1) with the license condition and then performs encryption using the encryption key ke to generate license information and sends it to the information storage section 1003 (step S703). The encrypted accounting object information is also input to the information storage section 1003 (step S704) and recorded on an information storage section 1004 together with the license information (step S705).

[0180] The information storage section 1004 comprises a medium such as a DVD-ROM, a DVD-RAM, or a hard disk. Information recorded on this medium is transferred to another medium (i.e., an information storage section 1015) directly or through broadcasting or the Internet and read out by the readout section 1012 in an information reproducing apparatus 1011 (step S706). The readout license information is sent to the decoder unit 1013 (step S707). The decoder unit 1013 holding the decoding key kd corresponding to the encryption key ke decodes the license information and extracts the decoding key kd(1) and license condition of the accounting object information. The decoder unit 1013 checks the license condition to decide whether the accounting object information can be used. If the accounting object information is usable, the decoder unit outputs the decoding key kd(1) to the reproduction section 1014 (step S708). The reproduction section 1014 extracts the accounting object information ke(1) from the readout section 1012 (step S709) and decodes it using the decoding key kd(1) to reproduce the accounting object information.

[0181] The decoder unit 1013 holds the decoding key kd and an algorithm for decoding license information. To avoid attack on security, the decoder unit 1013 is preferably mounted not as software but as, e.g., an IC chip. In this case, the decoder unit 1013 comprises an IC chip having a license information input section and an output section for outputting the decoding key of accounting object information (upon deciding that the accounting object information is usable). Decoding and decision of the use enable/disable condition are performed in the chip.

[0182] As one gist of the present invention, the license information generation section 1002 merges the decoding key kd(1) of accounting object information with the license condition and then performs encryption. Generally, encryption is performed/by scrambling information bits to be encrypted. Therefore, once encryption is performed, two pieces of information which have simultaneously been encrypted cannot be separated (without using decoding). It is important to disable separation of accounting object information from the license condition using the nature of encryption.

[0183] In the above-described example, the accounting object information is encrypted by the encryption key ke(1). Therefore,

[0184] 1. To use the accounting object information, the decoding key kd(1) is required. However, the decoding key kd(1) is encrypted into license information such that the decoding key and the license condition are inseparable. Although the license information and the accounting object information can be separated from each other, invalid license information does not contain the decoding key for properly decoding the accounting object information, so substitution of license information is meaningless.

[0185] 2. To obtain the correct decoding key kd(1), valid license information must be decoded. However,

[0186] 3. Only a proper decoder unit having the decoding key kd can perform this decoding.

[0187] 4. The proper decoder unit always refers to the license condition contained in the license information to decide the use enable/disable condition. Therefore,

[0188] 5. In the apparatus including the license information generation section and decoder unit of the present invention, the accounting object information cannot be used under an invalid license condition in principle.

[0189] If the decoder unit 1013 decides that the accounting object information cannot be used and does not output the decoding key kd(1), the license information must be updated or valid license information must be added to use the accounting object information. At this timing, accounting for the user of the information is generated. The user must update the license information or acquire new license information somehow by a shop or vending machine or through the Internet. An apparatus or vending machine set in a shop or a network server holds the decoding key kd and the encryption key ke and therefore can decode the license information and rewrite and reencrypt the information so as to update the license information.

[0190] If the user wants to update the license information (or obtain new license information), (one of) the license information added to the accounting object information must be sent to an apparatus having a license information update function.

[0191] 1. Only a proper apparatus having the decoding key kd and the encryption key ke can decode/separate the decoding key kd(1) and the license condition of the accounting object information.

[0192] 2. Only a proper apparatus having the decoding key kd and the encryption key ke can reencrypt the license information after the rewrite of the license condition.

[0193] The updated license information is output from the license information update apparatus (a license information update client section 403 shown in FIG. 26, a license information update unit 603 shown in FIG. 38, a license information update unit 702 shown in FIG. 41, or a license information update unit 804 shown in FIG. 47) and returned to the user's medium. The license information is kept encrypted outside the license information update apparatus.

[0194] 3. Since the license information has undergone encryption as a characteristic feature of the present invention, the license condition cannot be inadequately changed.

[0195] Generally, to transmit a decoding key through a network, the decoding key is often reencrypted using another key. However, as the characteristic feature of the present invention, the decoding key kd(1) for decoding the encrypted accounting object information is merged with the license condition and then encrypted. This provides a significant effect in protection and charge for accounting object information such as a work, as described above.

[0196] The arrangements and operations of the information recording apparatus, the information reproducing apparatus, and the accounting apparatus of the present invention will be described below in detail.

[0197] (1) Information Recording Apparatus

[0198] (1-1) First Example of Information Recording Apparatus

[0199] FIG. 1 shows the first arrangement of an information recording apparatus according to the present invention. More specifically, FIG. 1 shows an arrangement of an information recording apparatus which encrypts contents information (to be referred to as accounting object information hereinafter) as an accounting object such as a digitized work, encrypts the license condition of the accounting object information and a decoding key for decoding the encrypted accounting object information to generate license information, and records the encrypted accounting object information and license information on a predetermined recording medium.

[0200] The information recording apparatus roughly comprises an accounting object information input section 2, a license information generation section 3, and a recording section 8.

[0201] Accounting object information is encrypted in advance using the encryption key ke(1) and input to the accounting object information input section 2. A decoding key corresponding to the encryption key ke(1) is the decoding key kd(1). Encryption of information X using an encryption key K will often be expressed as X k hereinafter, as needed.

[0202] The license information generation section 3 is constituted by a license condition input section 4, a decoding key input section 5, a key holder section 6, and an encryption section 7.

[0203] The encryption key ke is stored in the key holder section 6 in advance. This encryption key ke does not always agree with the encryption key ke(1).

[0204] A license condition is input to the license condition input section 4. The license condition includes at least one of the expiration date of the accounting object information, the license information write time, the contents ID, the medium ID, and the decoder unit ID.

[0205] The decoding key kd(1) corresponding to the encryption key ke(1), which is used to decode the encrypted accounting object information, is input to the decoding key input section 5.

[0206] The license condition and the decoding key kd(1) are input to the encryption section 7 respectively through the license condition input section 4 and the decoding key input section 5. The license condition and the decoding key kd(1) are merged.

[0207] After this, the merged license condition and decoding key kd(1) are encrypted using the encryption key ke stored in the key holder section 6. Generally, encryption schema are roughly classified into a public key scheme and a secret key scheme, and either can be employed. The encrypted data is called-license information. As the characteristic feature of the encryption section 7, the license condition and the encryption key ke(1) are inseparably combined by merging and encryption. Therefore, an apparatus capable of decoding data encrypted using the encryption key ke, i.e., an apparatus having the decoding key kd corresponding to the encryption key ke can exclusively separate the license condition from the encryption key ke(1). The decoding key kd(1) is a key for decoding the encrypted accounting object information, so the accounting object information and the license condition are inseparably combined. The accounting object information and the license information as data can be always separated. However, without valid license information, the accounting object information cannot be decoded to use the contents.

[0208] The recording section 8 writes the license information in an information storage section 9 and then writes the encrypted accounting object information subsequent to the license condition.

[0209] The information storage section 9 may be a recording medium such as a DVD-ROM, a DVD-RAM, or a hard disk. Such a recording medium having information is set in a predetermined reproducing apparatus to reproduce the information. Alternatively, the information may be transferred from the information storage section 9 to another recording medium through a network such as the Internet or by broadcasting and reproduced by a predetermined reproducing apparatus.

[0210] FIG. 2 is a flow chart for explaining the operation of an information recording apparatus 1 shown in FIG. 1. First, the encrypted accounting object information ke(1) is input to the accounting object information input section 2 (step S1), the license condition is input to the license condition input section 4 (step S2), and the decoding key kd(1) is input to the decoding key input section 5 (step S3). The encrypted accounting object information is transferred from the accounting object information input section 2 to the recording section 8 (step S4), the license condition is transferred from the license condition input section 4 to the encryption section 7 (step S5), and the decoding key kd(1) is transferred from the decoding key input section 5 to the encryption section 7 (step S6). The encryption key ke held in the key holder section 6 in advance is transferred to the encryption section 7 (step S7). The encryption section 7 merges the license condition and the decoding key kd(1) and then performs encryption using the encryption key ke to generate license information (step S8). The generated license information is transferred to the recording section 8 (step S9). The recording section 8 merges the encrypted accounting object information and license information and records them on the information storage section 9 (step S10).

[0211] (1-2) Second Example of Information Recording Apparatus

[0212] FIG. 3 shows the second arrangement of an information recording apparatus according to the present invention. More specifically, FIG. 3 shows an arrangement of an information recording apparatus which encrypts part of accounting object information as an accounting object such as a digitized work together with a license condition to generate license information and records the remaining portion of the accounting object information and license information in a predetermined recording medium. As in the first arrangement shown in FIG. 1, part of accounting object information is encrypted together with a license condition to inseparately combine the accounting object information with the license condition.

[0213] The information recording apparatus roughly comprises a data separation section 12, a license information generation section 13, and a recording section 18.

[0214] The data separation section 12 divides accounting object information into two parts. FIGS. 5A, 5B, 6A, and 6B show examples of data separation by the data separation section. For the descriptive convenience, a still picture will be exemplified, though this method can be used for a motion picture and the like.

[0215] As shown in FIG. 5A, part (face regions in FIG. 5A) of a still picture may be extracted, and the face regions as shown in FIG. 5B may be encrypted as part of license information. In this case, the image can be seen without decoding the license information (i.e., without paying the fee) although the image is partially omitted. As shown in FIG. 6A, an image is subjected to Fourier transformation to extract a frequency component. A high-frequency component as shown in FIG. 6B may be encrypted as part of license information. In this case, unless the license information cannot be decoded (i.e., unless the fee is paid), no clear image can be obtained by reproducing the image with the frequency component shown in FIG. 6A.

[0216] The license information generation section 13 is constituted by a license condition input section 14, an encryption section 17, and a key holder section 16.

[0217] The key holder section 16 stores the encryption key ke in advance. The license condition input section 14 receives a license condition. The license condition includes at least one of the expiration date of the accounting object information, the license information write time, the contents ID, the medium ID, and the decoder unit ID. The license condition is input to the encryption section 17 through the license condition input section 14. Part of accounting object information, which is obtained by dividing the accounting object information into two parts, is also input from the data separation section 12 to the encryption section 17. The license condition and part of the accounting object information are merged and then encrypted using the encryption key ke stored in the key holder section 16 to generate license information.

[0218] The recording section 18 writes the license information in an information storage section 19 and then writes the remaining part of the accounting object information, which is obtained by dividing the accounting object information into two parts by the data separation section 12, subsequent to the license information.

[0219] The information storage section 19 may be a recording medium such as a DVD-ROM, a DVD-RAM, or a hard disk. Such a recording medium having information is set in a predetermined reproducing apparatus to reproduce the information. Alternatively, the information may be transferred from the information storage section 19 to another recording medium through a network such as the Internet or by broadcasting and reproduced by a predetermined reproducing apparatus.

[0220] FIG. 4 is a flow chart for explaining the operation of an information recording apparatus 11 shown in FIG. 3. Accounting object information is input to the data separation section 12 (step S21), and the license condition is input to the license condition input section 14 (step S22). The data separation section 12 divides the input accounting object information into two parts (step S23), transfers one part of the accounting object information to the encryption section 17 (step S24), and transfers the remaining part of the accounting object information to the recording section 18 (step S25). The license condition is transferred from the license condition input section 14 to the encryption section 17 (step S26). The encryption key ke is transferred from the key holder section 16 to the encryption section 17 (step S27). The encryption section 17 merges the license condition and the part of the accounting object information transferred from the data separation section 12 and then encrypts them to generate license information (step S28). The generated license information is transferred to the recording section 18 (step S29). The recording section 18 merges the part of the accounting object information transferred from the data separation section 12 and the license information and records them on the information storage section 19 (step S30).