JP2000242563A - Recording medium, and recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device capable of making the unauthorized use of the enciphered information difficult and easily using a software without impairing convenience. SOLUTION: A recording medium includes a reproduction-only part where the enciphered information is recorded and a rewrite part where the medium common key information that is converted into the decoding key information and the algorithm selection information that selects an algorithm to generate the decoding key information are recorded. A recording/reproducing device includes a control part 204 which performs the control to read out the enciphered information, algorithm selection information and medium common key information on the basis of the designated information, a rewrite area recording/reproducing part 202 which reads out the information on the rewrite part, a reproduction part reproducing processing part 203 which reads the information on the reproduction-only part, an algorithm database part 205 which stores the algorithm, a transposition converting part 206 which converts the medium common key information into the decoding key information by means of the algorithm and an enciphered information decoding part 207 which decodes the enciphered information by means of the decoding key information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a recording medium on which music, video, computer programs, etc. are recorded, and a reproducing apparatus for reproducing the recording medium.

[0002]

2. Description of the Related Art With the spread of recording media capable of recording a large amount of information, information such as music, video, computer programs, etc. can be stored in a compact disk (CD: Compact Disc) or a compact disk-read only memory (CD). C
It is common to record on a recording medium such as a D-ROM (Compact Disc-Read Only Memory) and distribute and sell it inexpensively and in large quantities.

[0003] Recording media such as CDs and CD-ROMs have digitized information recorded thereon and can be used without deteriorating the quality of the information. Since information recorded on a recording medium such as a CD or a CD-ROM can be easily copied by a personal computer, information recorded on a recording medium such as a CD or a CD-ROM is illegally copied. There is a fear.

For example, a computer program recorded on a CD-ROM is read by a personal computer, stored in a storage unit such as a hard disk drive of the personal computer, and the computer program stored in the storage unit is executed and used. . CD-RO
The computer program recorded in M can be stored in the hard disk drives of a plurality of personal computers and used illegally. Also, by using a personal computer to read a computer program recorded on a CD-ROM and recording the computer program on another recording medium, the computer program recorded on the CD-ROM can be illegally copied. Can be. The copied computer program can be used on another personal computer, and the copied computer program can be further copied on another recording medium.

[0005] As means for protecting a computer program that can be executed using a personal computer, information necessary for using the computer program (such as key information and a password) is checked. For example, there is a method in which a computer program can be used only by a computer, or a method in which a computer program itself is encrypted by some method and the computer program is decrypted and used by inputting decryption information. Even if these methods are used, there is a possibility that the computer program is illegally copied and used by copying the information necessary for using the computer program and the decoding information for decoding the data.

As means for solving the above-mentioned problem, there is a software right management control method disclosed in Japanese Patent Application Laid-Open No. 64-68835. In this method, an encrypted computer program is decrypted using a dedicated decryption device and used. The decryption device calculates the usage frequency every time the decryption process is performed, and transmits the calculated usage frequency to the distribution center as needed. The distribution center charges a fee according to the frequency of use, and collects a fee from the user of the computer program. Even if an encrypted computer program is copied using a dedicated decryption device, the copied computer program cannot be used unless it is decrypted by a dedicated decryption device. Because you will be charged each time you use a dedicated decryption device,
You must still pay for using illegally duplicated computer programs.

Further, in the software management system disclosed in Japanese Patent Application Laid-Open No. H5-298085, a non-rewritable recording medium having a rewritable rewritable area and a non-rewritable storage area is used. The encrypted software is recorded in the possible storage area, and the number of times or the time of use of the software is encrypted and recorded in the rewritable area together with the decryption information for decrypting the software. In a reproducing apparatus for reproducing the recording medium, use of the software is prohibited if the number of times or the time of use exceeds the number of contracts or the contract time.

[0008]

The above-described software right management control method and software management system include a computer program that can be executed using a personal computer and a computer program other than the computer program, such as music and video. It is difficult to prevent illegal duplication and use of information without impairing its convenience.

The above-mentioned software right management control method achieves sufficient security against illegally duplicating and using a computer program. However, for example, a predetermined fee is paid for information such as music and video. When a recording medium on which is recorded is purchased, there is a problem that a fee is charged every time a dedicated decoding device for reproducing information such as music and video is used. In the above-described software management system, the number of times and the time of use for information such as music and video are limited, so that there is a problem that convenience is impaired.

In the above-mentioned software right management control method, the encrypted information is falsified so that the encrypted information can be decrypted using a device other than a dedicated decryption device. As a result, the information can be illegally copied and used. In the above-mentioned software management system, the information recorded on the recording medium is falsified by falsifying the information on the number of times and time of use of the software, and the information recorded on the recording medium can be freely decrypted and illegally copied and used can do.

An object of the present invention is to provide a recording medium and a reproducing apparatus which make it difficult to falsify information and illegally copy and use it, and which can easily use information without impairing convenience. Aim.

[0012]

According to a first aspect of the present invention, there is provided a reproduction-only section in which a plurality of encrypted pieces of encrypted information are recorded, and a plurality of decryption keys for decrypting the plurality of pieces of encrypted information. A rewriting section in which medium common key information to be converted into information and algorithm selection information for selecting an algorithm for generating a plurality of decryption key information corresponding to each piece of encryption information from the medium common key information are recorded. Features.

According to a second aspect of the present invention, there is provided a playback-only section in which a plurality of encrypted pieces of encrypted information are recorded, and a medium converted into a plurality of pieces of decryption key information for decrypting the plurality of pieces of encrypted information. A recording / reproducing unit for recording / reproducing a recording medium provided with a rewrite unit in which common key information and algorithm selection information for selecting an algorithm for generating a plurality of decryption key information corresponding to each piece of encryption information from medium common key information are recorded. In the reproducing apparatus, a rewritable unit recording / reproducing processing unit for reading out algorithm selection information and recording medium common key information, a reproducing unit reproducing processing unit for reading out encrypted information, and a rewritable unit recording / reproducing process based on designated information input from the outside A control unit for controlling the reproduction processing unit, an algorithm database unit in which algorithms are stored, and an algorithm data base based on algorithm selection information. A transposition converter for converting the medium common key information to the decrypting key information using an algorithm read by selected from database unit rewriter recording and reproduction processing unit,
And an encryption information decryption unit that decrypts the encryption information using the decryption key information and converts the information into information.

According to a third aspect of the present invention, there is provided a reproduction-only section in which a plurality of encrypted pieces of encrypted information are recorded, and a medium converted into a plurality of pieces of decryption key information for decrypting the plurality of pieces of encrypted information. An algorithm selection information for selecting an algorithm for generating a plurality of decryption key information corresponding to each piece of encryption information from the common key information and the medium common key information, and a key hash generated based on the key information converted to the medium common key information And a rewriting section in which the value information is recorded.

According to a fourth aspect of the present invention, there is provided a playback-only section in which a plurality of encrypted pieces of encrypted information are recorded, and a medium converted into a plurality of pieces of decryption key information for decrypting the plurality of pieces of encrypted information. An algorithm selection information for selecting an algorithm for generating a plurality of decryption key information corresponding to each piece of encryption information from the common key information and the medium common key information, and a key hash generated based on the key information converted to the medium common key information A recording / reproducing apparatus for recording / reproducing a recording medium provided with a rewriting section for recording value information and a first hash value generating section for generating first hash value information based on algorithm selection information input from outside An encryption unit that encrypts key information input from the outside using the first hash value information and converts it into medium common key information, and a third unit that generates key hash value information based on the key information. A rewriting unit for recording the algorithm selection information, the medium common key information, and the key hash value information in the rewriting unit when the algorithm selection information and the key information are input from the outside. Features.

According to a fifth aspect of the present invention, there is provided a reproduction-only section in which a plurality of encrypted pieces of encrypted information are recorded, and a medium converted into a plurality of pieces of decryption key information for decrypting the plurality of pieces of encrypted information. An algorithm selection information for selecting an algorithm for generating a plurality of decryption key information corresponding to each piece of encryption information from the common key information and the medium common key information, and a key hash generated based on the key information converted to the medium common key information In a recording / reproducing apparatus for recording / reproducing a recording medium having a rewriting section in which value information is recorded, when a new algorithm selection information is input from outside, the medium common key information recorded in the rewriting section is read out A rewriting unit that reads and rewrites algorithm selection information together with a recording / reproducing processing unit, and is read from the rewriting unit when new algorithm selection information is input from outside. To generate a first hash value information based on the algorithm selection information, and the first hash value generation unit that generates a first hash value information new based on new algorithm selection information and algorithm selection information,
An encryption / decryption unit that converts the medium common key information read from the rewriting unit into the key information using the first hash value information, and converts the key information using the new first hash value information into new medium common key information And an encryption unit for converting the data into a character string.

According to a sixth aspect of the present invention, there is provided a read-only section in which a plurality of encrypted pieces of encrypted information are recorded, and a medium for converting the plurality of pieces of encrypted information into a plurality of pieces of decryption key information. An algorithm selection information for selecting an algorithm for generating a plurality of decryption key information corresponding to each piece of encryption information from the key information and the medium common key information, and a key hash value generated based on the key information converted into the medium common key information A recording / reproducing apparatus for recording / reproducing a recording medium having a rewriting section on which information is recorded, a rewriting section recording / reproducing processing section for reading out algorithm selection information, medium common key information, and key hash value information; A reproduction-dedicated-part reproduction processing unit that reads out, a control unit that controls the rewrite-unit recording / reproduction processing unit and the reproduction-dedicated-part reproduction processing unit based on designated information input from the outside, and a rewriting unit. A first hash value generation unit that generates first hash value information based on the extracted algorithm selection information, an encryption / decryption unit that converts medium common key information into key information using the first hash value information, Second to information
A second hash value generation unit for generating a hash value, and comparing the key hash value information read from the rewriting unit with the second hash value information generated by the second hash value generation unit to obtain two hash values A comparison unit that outputs a processing execution signal when the same is the same, an algorithm database unit that stores the algorithm, and an algorithm that is selected from the algorithm database unit based on the algorithm selection information based on the processing execution signal that is output from the comparison unit A transposition conversion unit that converts the medium common key information read from the rewriting unit into decryption key information using the decryption unit, and decrypts the encrypted information read from the playback-only unit using the decryption key information and converts it into information And an encryption information decryption unit that performs the encryption.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first example of a recording medium according to the present invention.
It is a schematic diagram which shows the schematic structure of an Example. In FIG.
The recording medium 101 includes a rewriting area (rewriting section) 102 and a reproduction-only area (reproduction-only section) 103. In the present embodiment, a description will be given assuming that the rewritable area 102 and the read-only area 103 are formed on the recording medium 101, but the present invention is not limited to this. The recording medium may include a read-only unit that reads information using light and a rewritable unit (for example, a rewritable memory) that can read and rewrite information in a non-contact manner by radio waves or the like.

The rewriting area 102 records medium common key information and algorithm selection information. In addition, medium-specific information indicating the manufacturing number (serial number) and manufacturing date of the manufacturer that manufactured the recording medium, and user information that is information on the user are recorded.

The medium common key information is converted into decryption key information used for decrypting a plurality of pieces of encrypted information recorded in the reproduction-only area 103 by a reproducing apparatus described later.
The medium common key information is information for generating respective decryption key information of all pieces of encryption information recorded in the reproduction-only area 103. One medium common key information is recorded on one recording medium 101. I have. The medium common key information is generated based on the key information input by the software provider when the user purchases the recording medium, and is recorded in the rewriting area 102. The key information input by the software provider is information used to determine whether the information on the recording medium 101 has been falsified.

The algorithm selection information generates decryption key information for decrypting the encryption information selected by the user from among a plurality of different algorithms stored in an algorithm database provided in the recording / reproducing apparatus described later. Information for selecting an algorithm for use. Since a plurality of decryption key information corresponding to each piece of encryption information recorded in the reproduction-only area 103 is converted from one medium common key information, an algorithm corresponding to the plurality of decryption key information is stored in the rewrite area 102. A plurality of algorithm selection information for selection is recorded.

The algorithm selection information is recorded when a user purchases a recording medium. Algorithm selection information corresponding to the encryption information selected by the user is recorded in the rewriting area 102 of the recording medium 101 by the software provider. When the user additionally purchases the encryption information recorded on the recording medium 101, the software provider additionally records the algorithm selection information corresponding to the additionally purchased encryption information in the rewriting area 102.

To reproduce the encrypted information recorded on the recording medium 101, when a user specifies a music number, for example, an algorithm database of a recording / reproducing apparatus described later is used according to algorithm selection information corresponding to the specified encrypted information. The algorithm stored in the section is selected, the medium common key information is converted into decryption key information by the algorithm, and the encryption information recorded in the read-only area 103 is decrypted by the decryption key information.

In the reproduction-only area 103, a plurality of pieces of encrypted information (music,
Information such as video and computer programs). The encryption information is information that is decrypted using the decryption key information, in other words, information that has been subjected to encryption processing using information corresponding to the decryption key information. For example, the first encryption information is the music information of the first music piece that is encrypted and decrypted by the first decryption key information, and the second encryption information is the music information of the second music piece that is decrypted by the second decryption key information. Music information. In this embodiment, all pieces of encryption information recorded in the reproduction-only area 103 are music information, but the present invention is not limited to this. For example, encrypted information of music information and encrypted information of video information may be mixedly recorded in the reproduction-only area 103.

A recording / reproducing apparatus for reproducing the recording medium 101 will be described. FIG. 2 is a schematic diagram showing a schematic configuration of the first embodiment of the recording / reproducing apparatus of the present invention. The recording / reproducing apparatus 201 includes a rewritable area recording / reproducing processing section (rewriting section recording / reproducing processing section) 202, a reproducing area reproducing processing section (reproducing-only section reproducing processing section) 203, a control section 204, an algorithm database section 205, and a transposition converting section 206. , An encryption information decryption unit 207.

The rewriting area recording / reproducing processing section 202 reads out the designated algorithm selection information from the rewriting area 102 of the recording medium 101 under the control of the control section 204, which will be described later, and outputs it to the algorithm database section 205.
Further, it reads the medium common key information from the rewriting area 102 of the recording medium 101 and outputs it to the transposition conversion unit 206.

The reproduction area reproduction processing unit 203 reads the encrypted information recorded in the reproduction only area 103 of the recording medium 101 under the control of the control unit 204 described later.

The control unit 204 causes the rewriting area recording / reproducing processing unit 202 to read the designated algorithm selection information from the rewriting area 102 based on the specification information input by the user using an operation unit (not shown). Control and
The playback area playback processing unit 203 controls the read-only area 103 to read the encrypted information specified by the specified information.

The algorithm database unit 205 includes:
A plurality of algorithms for generating decryption key information for decrypting the encrypted information from the medium common key information recorded on the recording medium 101 are stored. A plurality of pieces of encryption information recorded on one recording medium are decrypted with different decryption key information for each piece of encryption information.

The transposition conversion unit 206 converts the medium common key information output from the rewritable area recording / reproducing processing unit 202 into decryption key information using the algorithm output from the algorithm database unit 205.

As a method of converting the medium common key information into the decryption key information in the present embodiment, a method of generating N (M> N) bits of decryption key information from the M bits of medium common key information is described below.
There are a method and a second method of generating L (M <L) bits of decryption key information from M bits of medium common key information. In the present embodiment, M bits are replaced with an 8-bit character data string, N
The bit is a 4-bit character data string, and the L bit is an 11-bit character data string.

FIG. 3 is a schematic diagram for explaining a first method for converting medium common key information into decryption key information in the recording / reproducing apparatus of this embodiment. In FIG. 3, a first common key information for converting medium common key information into first and second decryption key information is shown.
The method will be described. For conversion to the first decryption key information,
The first algorithm selected by the first algorithm selection information is used.
It is converted into (M> N) -bit first decryption key information. As the medium common key information, the first, third, fourth, and seventh character data are used by the first algorithm, and are converted into first decryption key information for first encrypted information.

The conversion into the second decryption key information uses the second algorithm selected by the second algorithm selection information, and converts the M (M> N) bits of the third decryption key from the M-bit medium common key information. Converted to information. As the medium common key information, the second, fourth, sixth, and eighth character data are used by the second algorithm, and are converted into second decryption key information for second encrypted information. The character data of the medium common key information may be used repeatedly.

FIG. 4 is a schematic diagram for explaining a second method for converting medium common key information into decryption key information in the recording / reproducing apparatus of this embodiment. In FIG. 4, a second key for converting medium common key information into first decoding key information and second decoding key information.
The method will be described. For conversion to the first decryption key information,
The first algorithm selected by the first algorithm selection information is used, and L is obtained from the M-bit medium common key information.
It is converted into (M <L) -bit first decryption key information. In the medium common key information, a part of character data is redundantly used by the first algorithm, and is converted into first decryption key information for first encrypted information.

The conversion into the second decryption key information is performed by using the second
The second algorithm selected by the algorithm selection information is used, and L (M <M <
It is converted into L) bits of second decryption key information. In the medium common key information, part of character data is used redundantly by the second algorithm, and is converted into second decryption key information for second encrypted information.

The encryption information decryption unit 207 decrypts the encryption information output from the reproduction area reproduction processing unit 203 using the decryption key information, converts the information into unencrypted information, and outputs it.

The reproduction process of the recording / reproducing apparatus shown in FIG. 2 will be described. The recording medium 101 is placed in the recording / reproducing apparatus 201, and the user inputs, using an operation unit (not shown), designation information (music number to be reproduced) for reproducing desired information.

The control unit 204 controls the rewriting area recording / reproducing processing unit 202 based on the input specification information, and selects an algorithm specified from a plurality of pieces of algorithm selection information recorded in the rewriting area 102 of the recording medium 101. The selection information is read and output to the algorithm database unit 205. Further, the control unit 204 controls the rewriting area recording / reproducing processing unit 202 based on the input specification information, reads out the medium common key information recorded in the rewriting area 102 of the recording medium 101, Output.

The algorithm database unit 205 transposes an algorithm selected from a plurality of recorded algorithms based on the algorithm selection information output from the rewriting area recording / reproducing processing unit 202.
Output to

The transposition conversion unit 206 converts the medium common key information input from the rewritable area recording / reproducing processing unit 202 into decryption key information by using the selected algorithm, and sends it to the encryption information decryption unit 207 as decryption key information. Output.

On the other hand, the control section 204 controls the reproduction area reproduction processing section 203 based on the designated information, and
, The encrypted information specified by the specified information is read out and output to the encrypted information decryption unit 207.

The encryption information decryption unit 207 decrypts the encryption information output from the reproduction area reproduction processing unit 203 using the decryption key information output from the transposition conversion unit 206, converts the information into information, and outputs the information. .

Although a plurality of pieces of encrypted information are recorded on the recording medium 101, the recorded encrypted information cannot be decrypted without using decryption key information corresponding to each piece of encrypted information. . Since the decryption key information differs for each piece of encryption information, even if one piece of decryption key information is illegally generated, only one piece of encryption information recorded on the recording medium 101 can be reproduced. Information cannot be reproduced.

When the user purchases the recording medium 101,
The algorithm selection information for the required encryption information is purchased from a plurality of pieces of encryption information recorded on the recording medium 101. The user pays a fee for the encrypted information recorded on the recording medium 101 in accordance with the number of algorithm selection information corresponding to the encrypted information.

When reproducing the encrypted information,
The decryption key information for decrypting the encrypted information is
01, there is a very low risk that the decryption key information will be illegally decrypted or falsified into decryption key information that can easily decrypt multiple pieces of encrypted information. It is possible to prevent the decryption key information from being illegally copied and used.

FIG. 5 is a schematic diagram showing a schematic configuration of a second embodiment of the recording medium of the present invention. In FIG. 5, a recording medium 301 includes a rewrite area 302 and a read-only area 303. Medium common key information and algorithm selection information recorded in the rewrite area 302, and the read-only area 303
Is the same as in the first embodiment described above, and a description thereof will be omitted.

In the present embodiment, a description will be given assuming that the rewritable area 102 and the read-only area 103 are formed on the recording medium 101, but the present invention is not limited to this. The recording medium may include a read-only unit that reads information using light and a rewritable unit (for example, a rewritable memory) that can read and rewrite information in a non-contact manner by radio waves or the like.

The rewriting area 30 of the recording medium 301 of this embodiment
2 stores key hash value information. The key hash value information is a hash value (third hash value in FIG. 6 described later) generated based on the key information provided by the software provider when the user purchases the recording medium. . The medium common key information is information in which all the algorithm selection information recorded in the rewriting area 302 is a continuous data string, and the data string is encrypted using a hash generation function. In the recording / reproducing apparatus to be described later, it is possible to determine whether the medium common key information has been tampered with by obtaining a hash value from the medium common key information and comparing the hash value with the key hash value information recorded on the recording medium.

The hash value is obtained, for example, by a modulo operation (modulo method) for obtaining a remainder of 2 m.
The hash value obtained by the modulo operation is the same as the hash generation function used to easily generate an appropriate hash value (128 bits to 1024 bits) without having the same value (data string).
There is a Ge Digest 5 (MD5) algorithm. The MD5 is used for detecting the falsification of the contents of the electronic mail and for digital signature for certifying the source.

FIG. 6 is a schematic diagram showing a schematic configuration of a second embodiment of the recording / reproducing apparatus of the present invention. Recording medium 3 described above
01 in the recording / reproducing apparatus 401 used for reproducing the recording medium 301, when the user purchases the recording medium 301,
1, medium common key information, algorithm selection information, and key hash value information are recorded. When adding encryption information to be used, the algorithm selection information and the key hash value information are rewritten.

In FIG. 6, the recording / reproducing apparatus 401 includes a rewritable area recording / reproducing processing unit 402 and a reproducing area reproducing processing unit 40
3, control unit 404, algorithm database unit 40
5, transposition conversion section 406, encrypted information decryption section 407, first
Switching section 408, first hash value generation section 409, second switching section 410, encryption section 411, third hash value generation section 41
2, encryption / decryption unit 413, second hash value generation unit 414,
A comparison unit 415 is provided.

The rewritable area recording / reproducing processing section 402 reads the designated algorithm selection information from the recording medium 301 under the control of the control section 404 described later. Further, it reads out and rewrites algorithm selection information in the rewriting area 302 of the recording medium 301 and reads out key hash value information.

The reproduction area reproduction processing unit 403 reads the encrypted information recorded in the reproduction only area 303 of the recording medium 301 under the control of the control unit 404 described later.

The control unit 404 causes the rewriting area recording / reproducing processing unit 402 to read the specified algorithm selection information from the rewriting area 102 based on the specification information input by the user using the operation unit (not shown). Control and
The reproduction area reproduction processing unit 403 controls to read the encryption information specified by the specification information from the reproduction only area 303.

The algorithm database unit 405 stores an algorithm for converting medium common key information recorded in the rewriting area 303 of the recording medium 301 into decryption key information for decrypting encrypted information. Since the encryption information is decrypted by different decryption key information for each encryption information,
The algorithm database unit 405 stores an algorithm corresponding to the number of the encrypted information.

The transposition conversion unit 406 uses the algorithm output from the algorithm database unit 405 to
The medium common key information output from the rewritable area recording / reproducing processing unit 402 is converted into decryption key information.

The encryption information decryption unit 407 decrypts the encryption information output from the reproduction area reproduction processing unit 403 using the decryption key information, converts the information into unencrypted information, and outputs the information.

The first switching unit 408 switches between all algorithm selection information recorded on the recording medium 301 input from the rewriting area recording / reproducing processing unit 402 and additional algorithm selection information input from the outside. The hash value generation unit 409 is made to input.

The first hash value generation unit 409 generates first hash value information serving as a unique number using a hash generation function based on the N pieces of algorithm selection information recorded in the rewrite area 303 of the recording medium 301. I do.

The second switching unit 410 switches between key information provided by the software provider and medium common key information read from the recording medium 301 and decrypted by the encryption / decryption unit 413, and is input to the encryption unit 411. Let it. The key information is, for example, a password, a password or an ID number.

The encryption unit 411 encrypts the key information input via the second switching unit 410 using the first hash value generated by the first hash value generation unit 409 and converts it into medium common key information. I do. For example, a DES (Data Encryption Standard) algorithm is used as the encryption algorithm.

The third hash value generator 412 generates a third hash value based on key information input from the outside.

The encryption / decryption unit 413 decrypts the medium common key information recorded on the recording medium 301 into key information using the first hash value generated by the first hash value generation unit 409.

The second hash value generation section 414 generates a second hash value for the key information decrypted by the encryption / decryption section 413. The second hash value generator 414 obtains a hash value using the same method as the third hash value generator 412.

The comparing section 415 compares the key hash value information recorded on the recording medium 301 input from the rewriting area recording / reproducing processing section 402 with the second hash value input from the second hash value generating section 414. I do. As a result of comparison, 2
If the two hash values are the same, a signal for executing the process is output to the transposition conversion unit 406. If the two hash values are different, no signal for executing the process is output to the transposition conversion unit 406.

The processing operation of the recording / reproducing apparatus 401 of this embodiment will be described. When purchasing the recording medium 1, the key hash value information obtained from the key information provided by the software provider, the algorithm selection information corresponding to the encryption information required by the user, and the medium common key information Are recorded in the rewriting area 302 of the recording medium 301.

In the recording / reproducing apparatus 401, key information provided by the software provider and all key information corresponding to encryption information selected from a plurality of pieces of encryption information recorded in the reproduction-only area 303 of the recording medium 301. The algorithm selection information is input.

The key information is input to the encryption unit 411 via the second switching unit 410, and the algorithm selection information is
It is input to the first hash value generation unit 409 via the switching unit 408. All algorithm selection information is recorded in the rewriting area 302 of the recording medium 301 by the rewriting area recording / reproducing processing unit 402.

The first hash value generator 409 generates a first hash value based on the algorithm selection information. The encryption unit 411 encrypts the key information using the first hash value to generate medium common key information. The rewritable area recording / reproducing processing unit 402 records the medium common key information in the rewritable area 302 of the recording medium 1.

The third hash value generation section 412 generates a third hash value based on the key information input via the second switching section 410. Rewriting area recording / reproducing processing unit 40
2 indicates that the third hash value is stored in the rewriting area 30 of the recording medium 301.
Record in 2.

With the above processing, the medium common key information and the algorithm selection information are stored in the rewriting area 30 of the recording medium 301 so that only the encryption information required by the user is reproduced.
2 is recorded. When the recording medium 301 is reproduced, the user specifies the algorithm selection information (for example, music number), so that only the selected encryption information is decrypted in the recording and reproduction apparatus 201 of the first embodiment, as described above. , As unencrypted information.

A case where the user newly purchases the encrypted information recorded on the recording medium 301 will be described.
When the user purchases additional encryption information, that is, when additional encryption information is purchased in a state where the algorithm selection information corresponding to the already purchased encryption information is recorded on the recording medium 301, the recording medium 301 In the rewrite area 302, the algorithm selection information corresponding to the newly purchased encryption information is additionally recorded.

Since the medium common key information recorded on the recording medium 301 is information encrypted by the first hash value generated based on all the algorithm selection information recorded on the recording medium 301, When new encryption information is additionally purchased, the medium common key information is also changed.

The algorithm selection information recorded in the rewriting area 302 of the recording medium 301 is read by the rewriting area recording / reproducing processing unit 402 and input to the first hash value generation unit 409 via the first switching unit 408. You. The first hash value generation unit 409 generates a first hash value based on the algorithm selection information.

The medium common key information recorded in the rewritable area 302 of the recording medium 301 is read out by the rewritable area recording / reproducing processing unit 402 and input to the encryption / decryption unit 413. The encryption / decryption unit 413 includes a first hash value generation unit 409
Decrypts the medium common key information using the first hash value generated in step (1) and outputs the decrypted medium common key information. The key information decrypted by the encryption / decryption unit 413 is transmitted to the encryption unit 4 via the second switching unit 410.
11 is input.

On the other hand, when the algorithm selection information to be newly added (additional algorithm) is input to the recording / reproducing device 401, it is input to the first hash value generation unit 409 via the first switching unit 408. All the algorithm selection information recorded on the recording medium 301 is read by the rewritable area recording / reproducing processing unit 402 and input to the first hash value generation unit 409 via the first switching unit 408.

The first hash value generation unit 409 newly generates the first hash value (based on all the algorithm selection information read from the rewriting area 302 of the recording medium 301 and the input additional algorithm selection information). (A new first hash value).

The encryption section 411 encrypts the key information input via the second switching section 410 using the new first hash value to generate new medium common key information. The rewritable area recording / reproducing processing unit 402 records new medium common key information in the rewritable area 302 of the recording medium 301.

According to the above processing, when the algorithm selection information is added, the medium common key information and the algorithm selection information are rewritten, and the user can reproduce the newly purchased encryption information. Become.

In the recording / reproducing apparatus 410 of this embodiment, the second hash value obtained from the key information based on the medium common key information recorded in the rewriting area 302 of the recording medium 301 and the second hash value recorded on the recording medium 301 The comparison unit 415 compares the key hash value information and the second hash value with the key hash value. When the second hash value matches the key hash value, the transposition conversion unit 406 executes processing to decrypt the decryption key information, and Decrypt and output information.

The key hash value information recorded on the recording medium 301 is a hash value generated based on the key information provided by the software provider when the user purchases the recording medium 301, and includes algorithm selection information. Is information that is not changed even if is added.

On the other hand, the second hash value is obtained by decrypting, using the first hash value, the medium common key information obtained by encrypting the key information using the first hash value, using the first hash value. This is a hash value generated based on the information.

The second hash value represents the medium common key information as the first hash value.
This is information decrypted using the hash value, and becomes key information provided by the software provider. The second hash value generated by the second hash value generation unit 414 based on the key information is the same as the key hash value generated by the third hash value generation unit 412 based on the key information and recorded on the recording medium 301.

By comparing the second hash value with the key hash value, it can be determined whether the medium common key information, algorithm selection information or key hash value information recorded on the recording medium 301 has been tampered with. . If the information is tampered with, the encrypted information recorded on the recording medium 301 cannot be reproduced, and the information can be prevented from being illegally copied and used.

As described above, the encryption information recorded on the recording medium is encrypted with different decryption key information for each encryption information, and is reproduced with different decryption key information for each encryption information during reproduction. Further, it is possible to prevent illegally duplicating and using the encrypted information recorded in the read-only area by falsifying the information recorded in the recording medium.

In the recording medium and the recording / reproducing apparatus of the first and second embodiments described above, the algorithm for converting the medium common key information into the decryption key information is different based on one medium common key information. Although the algorithm can generate the decryption key information, the present invention is not limited to this. The encryption information may be decrypted by a different algorithm for each piece of encryption information based on one piece of decryption key information. As such an algorithm, an algorithm of the Data Encryption Standard (DES) can be used.

[0087]

According to the present invention, it is made difficult to falsify information and illegally copy and use the information, and the information can be used easily without impairing the convenience.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a first embodiment of a recording medium of the present invention.

FIG. 2 is a schematic diagram showing a schematic configuration of a first embodiment of the recording / reproducing apparatus of the present invention.

FIG. 3 is a schematic diagram for explaining a first method of converting medium common key information into decryption key information on the recording medium according to the embodiment.

FIG. 4 is a schematic diagram for explaining a second method of converting medium common key information into decryption key information in the recording / reproducing apparatus of the embodiment.

FIG. 5 is a schematic diagram showing a schematic configuration of a second embodiment of the recording medium of the present invention.

FIG. 6 is a schematic diagram showing a schematic configuration of a second embodiment of the recording / reproducing apparatus of the present invention.

[Explanation of symbols]

101 recording medium, 102 rewriting area, 103
Play only area. 201: recording / reproducing device, 202: rewriting area recording / reproducing processing section, 203: reproducing area reproducing processing section, 204: control section, 205: algorithm database section, 206: transposing conversion section, 207: encryption Decryption unit. 301 recording medium, 302 rewriting area,
303: Play-only area. 401 recording / reproducing device, 4
02: rewriting area recording / reproducing processing section, 403: reproducing area reproducing processing section, 404: control section, 405: algorithm database section, 406: transposing conversion section, 407:
An encrypted information decryption unit, 408... A first switching unit, 409.
First hash value generation unit, 410... Second switching unit, 411
..The encryption section, 412, the third hash value generation section, 41
3. an encryption / decryption unit, 414 an second hash value generation unit,
415. The comparison unit.

Claims (6)

[Claims] 1. A reproduction-only section in which a plurality of encrypted pieces of encrypted information are recorded, medium common key information converted into a plurality of pieces of decryption key information for decoding the plurality of pieces of encrypted information, and a common medium for the medium. A rewriting unit that stores algorithm selection information for selecting an algorithm for generating the plurality of decryption key information corresponding to each piece of encryption information from the key information. 2. A read-only section in which a plurality of encrypted pieces of encrypted information are recorded, medium common key information converted into a plurality of pieces of decryption key information for decoding the plurality of pieces of encrypted information, and a common medium for the medium. A recording / reproducing apparatus for recording / reproducing a recording medium including a rewriting section in which algorithm selection information for selecting an algorithm for generating the plurality of decryption key information corresponding to each piece of encryption information from key information is recorded. A rewritable unit recording / playback processing unit that reads algorithm selection information and the storage medium common key information; a playback unit playback processing unit that reads the encrypted information; and the rewritable unit recording / playback processing unit based on designation information input from the outside And a control unit that controls the reproduction-only unit reproduction processing unit, an algorithm database unit in which the algorithm is stored, and the A transposition conversion unit that converts the medium common key information into the decryption key information using the algorithm selected from the algorithm database unit, and a cipher that decrypts the encrypted information and converts the information into information using the decryption key information A recording / reproducing apparatus comprising: a decoding information decoding unit. 3. A reproduction-only section in which a plurality of encrypted pieces of encrypted information are recorded, medium common key information converted into a plurality of decryption key information for decoding the plurality of pieces of encrypted information, and a medium common medium. Algorithm selection information for selecting the algorithm for generating a plurality of decryption key information corresponding to each piece of encryption information from the key information and key hash value information generated based on the key information converted to the medium common key information include: A recording medium, comprising: a recorded rewriting unit. 4. A reproduction-only section in which a plurality of encrypted pieces of encrypted information are recorded, medium common key information converted into a plurality of pieces of decryption key information for decoding the plurality of pieces of encrypted information, and a common medium for the medium. Algorithm selection information for selecting the algorithm for generating a plurality of decryption key information corresponding to each piece of encryption information from the key information and key hash value information generated based on the key information converted to the medium common key information include: In a recording / reproducing apparatus for recording / reproducing a recording medium having a rewriting section to be recorded, a first hash value generating section for generating first hash value information based on algorithm selection information inputted from outside, An encryption unit that encrypts input key information using the first hash value information and converts the encrypted key information into the medium common key information, and a third encryption unit that generates key hash value information based on the key information. And a rewriting unit for recording the algorithm selection information, the medium common key information, and the key hash value information in the rewriting unit when the algorithm selection information and the key information are externally input. A recording / reproducing apparatus comprising: 5. A read-only section in which a plurality of encrypted pieces of encrypted information are recorded, medium common key information converted into a plurality of pieces of decryption key information for decoding the plurality of pieces of encrypted information, and a medium common key. Algorithm selection information for selecting the algorithm for generating a plurality of decryption key information corresponding to each piece of encryption information from the key information and key hash value information generated based on the key information converted to the medium common key information include: In a recording / reproducing apparatus for recording / reproducing a recording medium having a recorded rewriting section, when new algorithm selection information is externally input, the medium common key information recorded in the rewriting section is read and the A rewriting unit that reads and rewrites algorithm selection information; and a rewriting unit that reads and rewrites algorithm selection information from the rewriting unit when new algorithm selection information is input from outside. A first hash value generating unit that generates first hash value information based on the algorithm selection information and generates new first hash value information based on the new algorithm selection information and the algorithm selection information; An encryption / decryption unit that converts the medium common key information read from the rewriting unit into the key information using the first hash value information, and converts the key information into a new key information using the new first hash value information. A recording / reproducing apparatus comprising: an encryption unit that converts the information into medium common key information. 6. A reproduction-only section in which a plurality of encrypted pieces of encrypted information are recorded, medium common key information converted into a plurality of decryption key information for decoding the plurality of pieces of encrypted information, and the medium common key Algorithm selection information for selecting the algorithm for generating a plurality of decryption key information corresponding to each piece of encryption information from information and key hash value information generated based on the key information converted to the medium common key information are recorded. A recording / reproducing apparatus for recording / reproducing a recording medium having a rewritten section, wherein the rewriting section recording / reproducing processing section for reading out the algorithm selection information, the medium common key information, and the key hash value information; A read-only unit read processing unit to be read, a control unit that controls the rewritable unit recording / playback processing unit and the read-only unit playback processing unit based on designation information input from the outside, A first hash value generation unit that generates first hash value information based on the algorithm selection information read from the conversion unit, and converts the medium common key information into the key information using the first hash value information. An encryption / decryption unit, a second hash value generation unit for generating a second hash value for the key information, and comparing the key hash value information read from the rewriting unit with the second hash value information A comparison unit that outputs a processing execution signal when the two hash values are the same, an algorithm database unit storing the algorithm, and the algorithm selection information based on the processing execution signal output from the comparison unit. Transforms the medium common key information read from the rewriting unit into decryption key information using the algorithm selected from the algorithm database unit. Recording / reproduction, comprising: a transposition conversion unit that performs decoding; and an encryption information decryption unit that decrypts the encryption information read from the read-only unit using the decryption key information and converts the encrypted information into information. apparatus.