JPH11224461A - Information processor, information method, providing medium and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain intrincic information in a recording medium by decoding the intrincic information in the recording medium which are read out from the medium and are ciphered with an M series code. SOLUTION: At first, a disk ID encryption decoding circuit 21 receives an EDiscID which is read out from the read-in area of an optical disk 7 and which is an ciphered DiscID. Next, the circuit 21 generates an EDiscID by decoding the EDiscID based on the predetermined M series code which is suppied from an M series code generating circuit 22 to output it to the hash function circuit 25 of an effective master key generating module 23. Moreover, M series codes to be supplied from the circuit 22 are codes which are given when proper licences are granted from copyright holders.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an information processing apparatus, an information processing method, a providing medium, and a recording medium.
The present invention relates to an information processing apparatus, an information processing method, a providing medium, and a recording medium that enable more secure data transfer.

[0002]

2. Description of the Related Art In recent years, recording apparatuses and recording media for digitally recording information have become widespread. These recording devices and recording media, for example, record and reproduce video and music data without deterioration, so that data can be copied many times while maintaining its quality. However, if the copyright holder of the video or music data is concerned, there is a risk that the data for which he or she owns the copyright is illegally copied many times while maintaining its quality, and distributed to the market. Therefore, on the recording device and recording medium side,
It is necessary to prevent illegal copying of copyrighted data.

For example, in a mini disc (MD) (trademark) system, SCMS (Serial Copy Management System) is used.
A method called is used. This is information transmitted along with the music data by the digital interface. This information indicates that the music data is
Indicates whether the data is ree, copy once allowed, or copy prohibited. When the mini disc recorder receives music data from the digital interface, it detects SCMS and this is copy prohibited
If so, copy the music data without recording it on the mini disc.
If once allowed, this is changed to copy prohibited and recorded together with the received music data. If copy free, this is recorded as it is with the received music data.

[0004] In this manner, in the mini-disc system, the use of SCMS is used to prevent unauthorized copying of copyrighted data.

[0005] Another example of preventing unauthorized copying of copyrighted data is Digital Versatile.
There is a content scramble system in a Disk (DVD) (trademark) system. In this system, all the copyrighted data on the disk is encrypted,
Only licensed recording devices are given encryption keys,
Thus, the encrypted data can be decrypted and meaningful data can be obtained. And
When receiving a license, the recording device is designed so as to comply with operation rules such as not to perform unauthorized copying. In this way, in the DVD system, illegal copying of copyrighted data is prevented.

[0006]

However, in the method adopted by the above-mentioned mini disk system, SCMS is not used.
If it is copy once allowed, a recording device that does not comply with the operating rules, such as changing this to copy prohibited and recording it together with the received data, will be illegally manufactured.

The method adopted by the DVD system is effective for ROM media, but is not effective for RAM media on which a user can record data. In the case of RAM media, an unauthorized person can copy all data on the disk even if the encryption cannot be decrypted.
This is because illegally copying to a new disk makes it possible to newly create a disk that operates on a licensed and valid recording device.

The present invention has been made in view of such circumstances. For example, based on a secret key given only to a person who has been properly licensed by a copyright holder, information unique to a recording medium is obtained. By making it accessible, unauthorized copying is prevented.

[0009]

According to the present invention, there is provided an information processing apparatus comprising: a generating means for generating a first secret key; and a unique information of an encrypted recording medium recorded on the recording medium from the recording medium. And receiving means for receiving the first secret key generated by the generating means, decrypting the encrypted unique information of the recording medium received by the receiving means, and generating the unique information of the recording medium by using the first secret key generated by the generating means. It is characterized by having.

[0010] The information processing method according to claim 7 includes a generating step of generating a first secret key, and a receiving step of receiving, from the recording medium, unique information of the encrypted recording medium recorded therein. Generating a unique information of the recording medium by decrypting the encrypted unique information of the recording medium received by the receiving step with the first secret key generated by the generating step. Information processing method.

[0011] The providing medium according to claim 8 includes a generating step of generating a first secret key, a receiving step of receiving, from the recording medium, unique information of an encrypted recording medium recorded therein. The first generated by the generating step
Decrypting the encrypted unique information of the recording medium received in the receiving step with the use of the secret key, and generating the unique information of the recording medium.

A recording medium according to a ninth aspect is characterized in that information unique to a recording medium encrypted with an M-sequence code is recorded.

[0013] The information processing apparatus according to claim 1, and claim 7.
And a providing medium according to claim 8, wherein the first secret key is generated, and the unique information of the encrypted recording medium recorded therein is received from the recording medium, With the generated first secret key, the received unique information of the recording medium is decrypted, and the unique information of the recording medium is generated.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below. In order to clarify the correspondence between each means of the invention described in the claims and the following embodiments, each means is described. When the features of the present invention are described by adding the corresponding embodiment (however, an example) in parentheses after the parentheses, the result is as follows. However, of course, this description does not mean that each means is limited to those described.

The information processing apparatus according to the first aspect of the present invention includes a generator (for example, an M-sequence code generation circuit 22 in FIG. 3) for generating a first secret key (a predetermined M-sequence code), Receiving means for receiving the unique information (EDiscID) of the encrypted recording medium recorded therefrom (for example,
Using the DiscID encryption / decryption circuit 21 shown in FIG. 3) and the first secret key generated by the generating means, the unique information of the encrypted recording medium received by the receiving means is decrypted, and the unique information (DiscID) of the recording medium is decoded. ) (For example,
And a DiscID encryption / decryption circuit 21) shown in FIG.

The information processing apparatus according to the second aspect includes a random number generation means (for example, a random number generation circuit 10 in FIG. 3) for generating a random number when the encrypted unique information of the recording medium cannot be received from the recording medium. Recording means (for example, the DiscID encryption / decryption circuit 21 in FIG. 3) for encrypting a random number with the first secret key as unique information of the recording medium and recording it on the recording medium
Is further provided.

According to a third aspect of the present invention, a third secret key (effective master key Kem) is obtained based on the unique information of the recording medium generated by the generating means and the second secret key (master key Km). (For example, the hash function circuit 25 in FIG. 3) for calculating the predetermined information, and a recording means (for example, for encrypting predetermined information corresponding to the third secret key calculated by the calculating means and recording the information on a recording medium) , Kd in FIG.
And an encryption / decryption circuit 26).

In the information processing apparatus according to the present invention, the fourth secret key (encrypted disk key EKd) unique to the recording medium reproduced from the recording medium is encrypted by the third secret key. Decoding means (for example, the Kd encryption / decryption circuit 26 in FIG. 3) for decoding is further provided. The recording means encrypts and records predetermined information using the decrypted fourth secret key (master key Kd). It is characterized by recording on a medium.

An information processing apparatus according to claim 6, wherein the first decryption means decrypts the encrypted fourth secret key unique to the recording medium reproduced from the recording medium using the third secret key. (For example, the EKd decryption circuit 56 in FIG. 4) and second decryption means (for example, FIG. 4) for decrypting the encrypted data supplied from the recording medium using the decrypted fourth secret key. 4 EKs encryption circuit 57 and content data decryption circuit 58).

FIG. 1 shows a configuration example of an optical disk recording / reproducing apparatus to which the present invention is applied. The input unit 1 includes buttons,
It is composed of switches, remote controllers, etc.
When an input operation is performed by the user, a signal corresponding to the input operation is output. The control circuit 2 controls the entire apparatus according to a stored predetermined computer program.

The recording / reproducing circuit 3 includes an encryption unit 4 and a decryption unit 5
The decoding unit 5 decodes the data reproduced from the optical disk 7 by the pickup 6 and outputs the data to the outside as a reproduction signal. Upon receiving the supply of the recording signal from the outside, the encryption unit 4 encrypts the signal, supplies it to the pickup 6, and records it on the optical disk 7.

The pickup 6 records and reproduces data by irradiating the optical disk 7 with a laser beam. The spindle motor 9 is controlled by the servo circuit 8,
The optical disk 7 is rotated.

The servo circuit 8 drives the spindle motor 9 to rotate the optical disk 7 at a predetermined speed (for example, at a constant linear speed). The servo circuit 8 also controls a thread servo in addition to tracking and focusing of the pickup 6. The random number generation circuit 10
Under the control of the control circuit 2, a predetermined random number is generated.

On the optical disk 7, data having a structure as shown in FIG. 2 is recorded. In the lead-in area of the optical disk 7, there is provided an EDiscI in which the ID of the optical disk (hereinafter referred to as DiscID) is encrypted with a predetermined M-sequence code.
D, an encrypted disk key EKd obtained by encrypting the disk key Kd with the effective master key Kem is recorded.

The M-sequence code has "0" and "
The binary of 1 "is a pseudo-random binary signal (a kind of pseudo-random number) appearing at random, and DiscID is, for example, TOC (Table Of Contents) such as file name and directory information.
The data is encrypted by being embedded based on a predetermined M-sequence code set in advance. That is, DiscID
Is recorded as the time lag of the edge of the TOC data.
When such encryption is performed, the TOC data can be read without the M-sequence code (the TOC data is not encrypted), but the DiscID cannot be read (decoded) without the M-sequence code. . The present applicant has previously proposed a technique relating to such M-sequence code-based encryption as Japanese Patent Application No. 09-288960. The predetermined M-sequence code is given to a licensee together with a master key Km to be described later when a proper license is received from a copyright holder.

The effective master key Kem is calculated by applying the hash function to the combination of the master key Km and the DiscID according to equation (1). Effective master key Kem = hash (master key Km + DiscID) (1) Here, the master key Km is a secret key given only to a person (optical disk recording / reproducing apparatus) properly licensed from a copyright holder or the like. Here, for example, A and B
Means that when each is 32 bits, B is connected after A to form 64-bit data.

Each sector Si in the data area of the optical disk 7
(i = 1, 2,...) is composed of a header and a main data part, and the header includes an encrypted sector key EKsi (i = 1, 2,...) obtained by encrypting the sector key Ksi with the disk key Kd. (Here, i of Ksi indicates the number of the sector, and since the sector key is different for each sector, it is described as Ksi, but it is also described as Ks when there is no particular need to distinguish it.) The main data section stores encrypted content data obtained by encrypting the content data with the sector key Ksi.

FIG. 3 shows a configuration example of the encryption unit 4. The DiscID encryption / decryption circuit 21 decodes the EDiscID read from the optical disc 7 based on the M-sequence code supplied from the M-sequence code generation circuit 22 to generate a DiscID. The DiscID encryption / decryption circuit 21 also includes a random number generation circuit 1
A random number generated from 0 is received as a DiscID, and based on the M-sequence code supplied from the M-sequence code generation circuit 22, as described above, it is encrypted so as to be embedded in the input TOC information, and an EDiscID is generated. Is recorded on the optical disk 7.

The M-sequence code generation circuit 22 is composed of, for example, a plurality of flip-flops connected in series and an exclusive OR circuit, and generates a predetermined M-sequence code. Alternatively, it can be constituted by ROM, EEPROM, or the like.

The Km memory 24 of the Kem generation module 23
Stores the master key Km. Kem generation module 23
The hash function circuit 25 generates a combination of the master key Km and the DiscID, and calculates the effective master key Kem by applying the hash function to the combination.

The Kd encryption / decryption circuit 26 decrypts the encrypted disk key EKd read from the optical disk 7 with the effective master key Kem to generate a disk key Kd. The Kd encryption / decryption circuit 26 also includes the random number generation circuit 10
Receives the random number generated from as the disk key Kd,
Encrypted with the effective master key Kem to generate an encrypted disk key EKd, which is recorded on the optical disk 7.

The Ks encryption circuit 27 receives the random number generated from the random number generation circuit 10 as the sector key Ks, encrypts the random number with the disk key Kd, generates an encrypted sector key EKs, and records it on the optical disk 7. The content data encryption circuit 28 encrypts the content data with the sector key Ks and records the content data on the optical disc 7.

Next, FIG. 4 shows a configuration example of the decoding unit 5.
The EDiscID decoding circuit 51 decodes the EDiscID read from the optical disk 7 based on the M-sequence code supplied from the M-sequence code generation circuit 52 to generate a DiscID. M
The sequence code generation circuit 52 has the same configuration as that of the M sequence code circuit 22, and is configured to generate the same M sequence code as that of the M sequence code generation circuit 22.

Km memory 54 of Kem generation module 53
Stores the master key Km. Kem generation module 53
The hash function circuit 55 generates a combination of the master key Km and the DiscID, and applies the hash function to the combination to calculate the effective master key Kem. This Kem generation module 53
The configuration may be the same as that of the Kem generation module 23, and both may be used.

The EKd decryption circuit 56 decrypts the encrypted disk key EKd read from the optical disk 7 with the effective master key Kem to calculate the disk key Kd. The EKs decoding circuit 57 reads each sector Si from the optical disc 7.
Read out the encrypted sector key EKs recorded in the header of, and decrypt with the disk key Kd to calculate the sector key Ks. The content data decoding circuit 58
Decrypts the encrypted content data read out from the storage device with the sector key Ks.

Next, a processing procedure in the encryption unit 4 when user data is recorded on the optical disk 7 will be described with reference to a flowchart of FIG. In the case of this example, it is assumed that the DiscID is written on the optical disc 7 when the optical disc 7 is manufactured.

First, in step S31, DiscID
The encryption / decryption circuit 21 outputs the ED, which is the encrypted DiscID, read from the lead-in area of the optical disc 7.
Receives iscID. The DiscID encryption / decryption circuit 21 further includes an M-sequence code generation circuit 22 in step S32.
EDiscID based on the predetermined M-sequence code supplied from
To generate a DiscID, and the Kem generation module 23
To the hash function circuit 25. The M-sequence code supplied by the M-sequence code circuit 22 is given when a proper license is received from the copyright holder.

In step S33, the hash function circuit 25 of the Kem generation module 23
The master key Km is read from the third Km memory 24. Kem
In step S34, the hash function circuit 25 of the generation module 23 further stores the data of the optical disk 7 according to the above-described equation (1).
The hash function is applied to the combination of the DiscID and the master key Km to calculate an effective master key Kem, which is supplied to the Kd encryption / decryption circuit 26.

Next, in step S35, the Kd encryption / decryption circuit 26 receives the encrypted disk key EKd read from the lead-in area of the optical disk 7. The Kd encryption / decryption circuit 26 determines in step S36 that the optical disk 7
It is determined whether or not the encrypted disk key EKd has been written in the lead-in area (i.e., whether or not the encrypted disk key EKd has been received). If it is determined that the encrypted disk key EKd has not been written, the process proceeds to step S37, where the random number generation circuit 10 generates a 40-bit random number and outputs it to the Kd encryption / decryption circuit 26 as the disk key Kd.

Next, in step S38, the Kd encryption / decryption circuit 26 encrypts the disk key Kd supplied from the random number generation circuit 10 with the effective master key Kem received from the hash function circuit 25, and EKd is generated and recorded in the lead-in area of the optical disc 7.

In step S36, the encrypted disk key EK
If it is determined that d has been written, step S3
9 and the Kd encryption / decryption circuit 26
The encrypted disk key EKd read from the hash function circuit 25 as an effective master key Kem.
To obtain the disk key Kd. The Kd encryption / decryption circuit 26 outputs the disk key Kd to the Ks encryption circuit 27.

After the processing in step S38 or S39,
In step S40, the random number generation circuit 10 generates a 40-bit random number and uses it as the sector key Ks.
7 and the content data encryption circuit 28. In step S41, the Ks encryption circuit 27 determines whether the Kd encryption / decryption circuit 26 (the encrypted disk key EKd is
) Or the disk key Kd received from the random number generation circuit 10 (when the encrypted disk key EKd is not recorded on the optical disk 7), and encrypts the sector key Ks received from the random number generation circuit 10. , And generates an encrypted sector key EKs. The Ks encryption circuit 27 also records the encrypted sector key EKs in a sector header in the data area of the optical disk 7.

Next, in step S42, the content data encryption circuit 28 encrypts the content data with the sector key Ks (received from the random number generation circuit 10 in step S40) and stores the encrypted content data in the main data portion of the data area of the optical disk 7. Record.

In step S43, each circuit of the encryption unit 4 determines whether or not all the content data has been recorded. If it is determined that all the content data has not been recorded yet, the process proceeds to step 44, where each circuit of the encryption unit 4 accesses a sector of the optical disc 7 on which data has not been recorded, and returns to step S40. Hereinafter, the same processing is repeated. When it is determined in step S43 that all content data has been recorded, each circuit of the encryption unit 4 ends all recording processing.

As described above, when a proper license is received from the copyright holder, the encrypted DiscID is decrypted with the given predetermined M-sequence code, and the DiscID is obtained. Is recorded on the recording medium.

Next, a description will be given of a processing procedure in the encryption unit 4 when recording user data on the optical disc 7 on which no DiscID is recorded at the time of manufacturing, with reference to the flowchart of FIG.

First, in step S51, DiscID
The encryption / decryption circuit 21 receives the EDiscID read from the lead-in area of the optical disk 7, and the Kd encryption / decryption circuit 26 receives the encrypted disk key EKd read from the lead-in area of the optical disk 7.

Next, in step S52, the DiscID encryption / decryption circuit 21 determines whether or not EDiscID has been written in the lead-in area of the optical disk 7 (whether or not EDiscID has been received). The Kd encryption / decryption circuit 26 determines whether or not the encrypted disk key EKd has been written in the lead-in area of the optical disk 7 (whether or not the encrypted disk key EKd has been received). If it is determined that both the EDiscID and the encrypted disc key EKd have not been written, the process proceeds to step S53, where the random number generation circuit 10 generates a 128-bit random number and outputs it as a DiscID to the DiscID encryption / decryption circuit 21. .

Next, in step S54, the DiscID encryption / decryption circuit 21 receives the data supplied from the random number generation circuit 10.
Based on the M-sequence code supplied from the M-sequence code generation circuit 22, the DiscID is encrypted so as to be embedded in the TOC information, as described above, to generate an EDiscID, and recorded in the lead-in area of the optical disk 7. I do.

Next, in step S55, the hash function circuit 25 of the Kem generation module 23 reads the master key Km from the Km memory 24 of the Kem generation module 23. In step S56, the hash function circuit 25 of the Kem generation module 23 uses the optical disk 7 according to the above-described equation (1).
The hash function is applied to the combination of the DiscID and the master key Km read from the Km memory 24 to calculate an effective master key Kem, and supplies the result to the Kd encryption / decryption circuit 26.

Next, in step S57, the random number generation circuit 10 generates a 40-bit random number,
It outputs to the Kd encryption / decryption circuit 26 as Kd. In step S58, the Kd encryption / decryption circuit 26 encrypts the disk key Kd supplied from the random number generation circuit 10 with the effective master key Kem received from the hash function circuit 25 to generate an encrypted disk key EKd. 7 is recorded in the lead-in area.

If it is determined in step S52 that the EDiscID and the encrypted disk key EKd have been written, the process proceeds to step S59, where the DiscID encryption / decryption circuit 21 converts the EDiscID read from this optical disk into an M-sequence. Decoding with the M-sequence code supplied from the coding circuit 22
Generate

In step S60, the hash function circuit 25 of the Kem generation module 23
The master key Km is read from the third Km memory 24. Kem
The hash function circuit 25 of the generation module 23
At 61, the DiscID of the optical disk 7 is calculated according to the above-described equation (1).
The hash function is applied to the combination of the master key Km and the effective master key Kem, and the Kd encryption / decryption circuit 26 is calculated.
To supply.

Next, in step S62, the Kd encryption / decryption circuit 26 decrypts the encrypted disk key EKd read from the optical disk 7 with the effective master key Kem received from the hash function circuit 25, and Get Kd. The Kd encryption / decryption circuit 26 outputs the disk key Kd to the Ks encryption circuit 27.

After the processing in step S58 or S62, the process proceeds to step S63, but in steps S63 to S6.
The processing performed in step S7 corresponds to steps S40 to S44 in FIG.
Is the same as the processing performed in step (1). If it is determined that all the content data have been recorded, all the recording processing ends.

As described above, the DiscID is generated and recorded on the recording medium, and the encrypted content data corresponding to the generated DiscID and the master key Km is recorded on the recording medium. For this reason, for example, content data copied on an existing recording medium (recording medium on which DiscID is not recorded) can be reproduced as meaningful information by a person who has not been properly licensed from the copyright holder. Can not.

Next, referring to the flowchart of FIG.
The reproduction process of the user data performed by the decoding unit 5 will be described. First, in step S81, the EDiscID decoding circuit 51 receives an EDiscID, which is an encrypted DiscID, read from the lead-in area of the optical disc 7. The EDiscID decoding circuit 51 further performs step S82
In step (1), based on the M-sequence code supplied from the M-sequence code generation circuit 52, the EDiscID is decoded to generate a DiscID and output to the hash function circuit 55 of the Kem generation module 53.

Next, in step S83, the hash function circuit 55 of the Kem generation module 53 receives the DiscID output from the EDiscID decoding circuit 51, reads the master key Km from the Km memory 54, and obtains the above equation (1).
In accordance with the above, the combination of the Disc ID of the optical disc 7 and the master key Km
An effective master key Kem is calculated by applying the hash function, and supplied to the EKd decryption circuit 56.

In step S84, the EKd decoding circuit 5
6 receives the encrypted disk key EKd read from the lead-in area of the optical disk 7. EKd decoding circuit 56
Decrypts the read encrypted disk key EKd with the effective master key Kem received from the hash function circuit 55 to calculate a disk key Kd and outputs it to the EKs decryption circuit 57 in step S85.

Next, in step S86, the EKs decryption circuit 57 receives the encrypted sector key EKsi (i = 1, 2,...) Of each sector read from the data area of the optical disk 7. In step S87, the EKs decryption circuit 57 decrypts the read encrypted sector key EKsi with the disk key Kd received from the EKd decryption circuit 56, calculates the sector key Ksi, and outputs the calculated sector key Ksi to the content data decryption circuit 58. .

In step S88, the content data decryption circuit 58 receives the encrypted content data read from the optical disk 7. In step S89, the content data decryption circuit 58 decrypts the read encrypted content data using the sector key Ksi received from the EKs decryption circuit 57 and outputs the decrypted content data as a reproduction signal.

Next, in step S90, the decoding unit 5
Each circuit determines whether or not all the content data has been read from the data area of the optical disk 7. If it is determined that all the content data have not been read yet, the process proceeds to step S91, and each circuit of the decoding unit 5 receives the supply of the data of the next sector of the optical disk 7 that has not been read yet. The processing after step S86 is repeated. When it is determined that all content data has been read, each circuit of the decoding unit 5 ends all the reproduction processing.

As described above, the ID of the recording medium is generated, encrypted with a predetermined M-sequence code, and recorded on the recording medium.
Make the recording medium accessible.

The present invention is also applicable to the case where data is recorded or reproduced on a recording medium other than an optical disk.

In the present specification, a providing medium for providing a user with a computer program for executing the above processing includes an information recording medium such as a magnetic disk and a CD-ROM, and a network such as the Internet and a digital satellite. Transmission media is also included.

[0066]

According to the information processing apparatus according to the first aspect, the information processing method according to the seventh aspect, and the providing medium according to the eighth aspect, the information is recorded on the recording medium by the first secret key. Decrypt the unique information of the encrypted recording medium,
Since the unique information of the recording medium is generated, for example, it is difficult for a person who does not have a predetermined M-sequence code to access the recording medium.

According to the information processing apparatus of the second aspect,
When it is not possible to receive the encrypted unique information of the recording medium from the recording medium, the random number is encrypted as the unique information of the recording medium and recorded on the recording medium. Those who do not can not reproduce the information recorded on the recording medium where the unique information of the recording medium is not recorded.

According to the information processing apparatus of the third aspect,
The unique information of the recording medium generated by the generating means;
The third secret key is calculated based on the third secret key, and predetermined information is encrypted and recorded on the recording medium in accordance with the calculated third secret key. This makes it more difficult for a person who does not have the M-sequence code to access the recording medium.

According to the recording medium of the ninth aspect, the information unique to the recording medium encrypted with the M-sequence code is recorded, so that the information unique to the recording medium can be provided to the information processing apparatus. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of an optical disk recording / reproducing apparatus to which the present invention is applied.

FIG. 2 is a diagram illustrating data recorded on an optical disc.

FIG. 3 is a diagram showing an internal configuration of an encryption unit 4 of FIG. 1;

FIG. 4 is a diagram showing an internal configuration of a decoding unit 5 of FIG.

FIG. 5 is a flowchart illustrating an operation of the encryption unit 4 of FIG. 1;

FIG. 6 is a flowchart illustrating another operation of the encryption unit 4 of FIG. 1;

FIG. 7 is a flowchart illustrating an operation of the decoding unit 5 of FIG. 1;

[Explanation of symbols]

Reference Signs List 1 input section, 2 control circuit, 3 recording / reproducing circuit, 4 encryption section, 5 decoding section, 6 pickup, 7 optical disk, 8 servo circuit, 9 spindle motor, 10 random number generation circuit, 21 DiscID encryption / decryption circuit, 22 M Sequence code generation circuit, 23 Kem generation module, 24 Km
Memory, 25 hash function circuit, 26 Kd encryption / decryption circuit, 27 Ks encryption circuit, 28 content data encryption circuit, 51 EDiscID decryption circuit, 52 M-sequence code generation circuit, 53 Kem generation module, 54 Km memory,
55 hash function circuit, 56 EKd decoding circuit, 57 EKs decoding circuit, 58 content data decoding circuit

Claims (9)

[Claims] 1. An information processing apparatus for recording or reproducing information on a removable recording medium, comprising: a generating means for generating a first secret key; and the encrypted recording recorded on the recording medium from the recording medium. Receiving means for receiving the unique information of the medium; and a first secret key generated by the generating means,
An information processing apparatus comprising: a generating unit configured to decrypt the encrypted unique information of the recording medium received by the receiving unit and generate unique information of the recording medium. 2. When the encrypted unique information of the recording medium cannot be received from the recording medium, a random number generating means for generating a random number; and the first secret key converts the random number into the unique information of the recording medium. The information processing apparatus according to claim 1, further comprising: a recording unit configured to encrypt the information and record the encrypted information on the recording medium. 3. A calculating means for calculating a third secret key based on the unique information of the recording medium generated by the generating means and a second secret key, and the third secret key calculated by the calculating means. 3. A recording unit for encrypting predetermined information corresponding to the secret key of No. 3 and recording the encrypted information on the recording medium.
An information processing apparatus according to claim 1. 4. The information processing apparatus according to claim 3, wherein the predetermined information is a secret key unique to the recording medium. 5. The recording device according to claim 3, further comprising: a decryption unit that decrypts an encrypted fourth secret key unique to the recording medium reproduced from the recording medium using the third secret key. The information processing apparatus according to claim 3, wherein predetermined information is encrypted using the decrypted fourth secret key, and the encrypted information is recorded on the recording medium. 6. A first decryption means for decrypting an encrypted fourth secret key unique to the recording medium reproduced from the recording medium using the third secret key; and 4. The information processing apparatus according to claim 3, further comprising a second decryption unit that decrypts the encrypted data supplied from the recording medium using a fourth secret key. 7. An information processing method for an information processing apparatus for recording or reproducing information on a removable recording medium, comprising: a generating step of generating a first secret key; and an encryption function recorded on the recording medium from the recording medium. Receiving the received unique information of the recording medium, and decrypting the encrypted unique information of the recording medium received in the receiving step by the first secret key generated in the generating step, A generating step of generating unique information of the recording medium. 8. A computer program for use in an information processing apparatus for recording or reproducing information on a removable recording medium, comprising: a generating step for generating a first secret key; Receiving the encrypted unique information of the recording medium, and decrypting the encrypted unique information of the recording medium received by the receiving step with the first secret key generated by the generating step. And a generating step of generating unique information of the recording medium. 9. A recording medium mounted on an information processing apparatus and recording or reproducing information, wherein information unique to the recording medium encrypted with an M-sequence code is recorded.