JP4620136B2 - Information recording device - Google Patents

Description

  The present invention relates to a recording / reproducing apparatus for contents such as images and sounds.

Digital content playback devices such as CD players have good sound quality,
There are many users because there is little deterioration in sound quality due to long-term use.

However, although the content is digital, it is possible to copy without deterioration by faithfully copying the original bit by bit, and such devices are actually sold. The existence of such a copy device is a great advantage for the content user, but it is not preferable because it greatly affects the sales of the content from the content supplier. For this reason, content suppliers counter this by not supplying content to new digital devices (and media).

However, this situation has become a major obstacle to the spread of new electronic devices, and not only can most people enjoy the convenience, but also content providers have lost business opportunities.

On the other hand, private duplication for private use is a right recognized by the Copyright Act. In fact, many electronic devices up to now have restrictions on duplication methods (such as restrictions on analog recording). There have been recognized. However, if digital recording becomes mainstream in the future, it will be difficult to distinguish between private reproduction and public reproduction, and at the same time it will be difficult to distinguish private use.

Here, private reproduction means copying by a person who does not have the sales right of the source, and public copying means copying by a person who has the sales right of the source. That is, public copying can be obtained only by means equivalent to conventional content sales, and includes sales from electronic stores on the Internet.

In view of the above problems, the present invention switches the playback method of the content depending on whether the content is a public copy or a private copy, and the public copy allows an advantageous form of use over the private copy. Information reproducing apparatus, information recording apparatus, and information reproducing apparatus that can increase the demand for public duplication on official sales channels and build an information distribution mechanism that is of interest to content suppliers, content users, and electronic equipment suppliers An object is to provide an information sales apparatus, an information purchase apparatus, and an information vending machine.

In the present invention, in order to solve the above-described problem, the use of encrypted content is controlled by the license information corresponding to the encrypted content, and at the same time, content sales are permitted for the license information corresponding to the encrypted content that is a public copy. By signing with a private key of public key cryptosystem known only by the content sales server that is being used, the public copy and private copy are discriminated by the presence or absence of a digital signature,
Based on the determination result, the reproduction means of the content is changed, and a system in which the public reproduction can be reproduced by the reproduction means more advantageous than the private reproduction is realized.

(1) An information reproducing apparatus according to the present invention is an information reproducing apparatus that reproduces content information based on license information necessary for reproducing the content information added to the content information. The discriminating means for discriminating whether it is publicly duplicated content information or privately duplicated content information based on the contents of the license information, and the content information discriminated as privately duplicated content information by this discriminating means is the publicly duplicated content And reproducing means for reproducing the data with restrictions stricter than information.

Further, based on verification information for verifying that it is a public copy included in the license information, it is determined whether it is public copy content information or private copy content information.

In addition, regarding the use conditions of the content information included in the license information, private copy content information is more restricted than public copy content information.

The license information added to the content information is encrypted and decrypted with key information created based on information depending on the identifier of the recording medium on which the content information is recorded.

The determining means determines whether the content information is original content information based on the content of the license information. When the content information is determined to be original content information, the content information is reproduced indefinitely. 2 reproduction means.

According to the information reproducing apparatus of the present invention, there is a structural difference in the reproduction method between the privately copied content, the publicly copied content, and the original content, thereby preventing the expansion of private use while allowing private copying, and copyright. And protecting content suppliers.

In addition, when the content is illegally transferred to another recording medium, that is, copied, the license information depends on the recording medium. For example, the license information cannot be decrypted, and as a result, the content cannot be decrypted. Therefore, whether it is a private copy or a public copy, the license information must be recreated for copying, and only a valid recording device (for example, knowing the function f) can do so. Therefore, unauthorized use can be prevented because the number of copying can be surely restricted.

  (2) An information recording apparatus according to an embodiment of the present invention is an information recording apparatus for recording content information and license information necessary for reproducing the content information on a recording medium. And the type of the content information indicated by the license information when the type of the content information indicated by the license information is publicly copied content information copied by a sales rights holder Is modified to privately copied content information copied by a person who does not have a sales right, and recording means for recording the input content information on the recording medium together with the license information corrected by the correcting means It is characterized by comprising.

The information recording apparatus of the present invention includes content information (which may be encrypted or not encrypted) and license information (encryption) required for reproducing the content information added to the content information. In a recording medium, a discriminating unit for discriminating the type of the input content information, the type discriminated by the discriminating unit, and the above-mentioned Creating means for creating the license information based on information dependent on the identifier of the recording medium and use conditions of the content information; and recording means for recording the content information on the recording medium together with the license information created by the creating means; It has.

In the information recording apparatus, content information to be recorded may be limited to an analog signal.

According to the information recording apparatus of the present invention, by determining the type of content and providing an environment that can be copied only with stricter restrictions than the source content,
Differentiate publicly replicated content and privately replicated content on official sales channels, and contribute to the expansion of the market for publicly replicated content by relatively increasing the value of publicly replicated content.

In addition, when the content is illegally transferred to another medium, that is, copied, the license information is dependent on the media. For example, the license information cannot be decrypted, and as a result, the content cannot be decrypted. Whether it is a private copy or a public copy, the license information must be recreated for copying, and only a valid recording device (for example, knowing the function f) can do so. Unauthorized use can be prevented because the number of times can be reliably limited.

In addition, by limiting the source content to be recorded to analog only, when recording digital content, it can cause qualitative degradation of the content each time it is duplicated, which serves as a deterrent to duplication and publicly duplicated content It is possible to more reliably increase the value of and secure the sales market for publicly reproduced content.

(3) The information recording apparatus of the present invention is an information recording apparatus for recording content information and license information necessary for reproducing the content information added to the content information on a recording medium. Creating means for creating the license information including verification information for verifying that the information is dependent on the content information and a usage condition of the content information, and the content information together with the license information created by the creating means Recording means for recording information on the recording medium.

This information recording apparatus can be used particularly for a content sales apparatus and a content purchase apparatus for selling and purchasing publicly copied content.

In addition, since the license information creates license information depending on the recording medium, it is necessary to recreate the license information for copying, whether it is a private copy or a public copy. Since this is only a valid recording device (for example, knowing the function f), it is possible to reliably limit the number of copies and prevent unauthorized use.

As described above, according to the present invention, content copied through a legitimate route (
(Publicly copied content) can be distributed in a more advantageous form than content copied without legitimate authority. As a result, it is possible to increase the demand for publicly replicated content and provide an information distribution mechanism that is of interest to content suppliers, content users, and electronic device suppliers.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, terms used in the following description will be described.

The license information includes information embedded in the content itself and external information associated with the encrypted content as additional information. Here, the former is realized by an analog layer using a digital watermark technique, and is referred to as analog license information here. Since the latter is realized by a digital layer, it is called digital license information. Furthermore, both are collectively referred to as license information.

There are three types of content input to the content recording / playback apparatus of the present invention: original content, publicly copied content, and privately copied content.

The original content is self-produced content or content that is copy-free and has no specific usage restrictions. For this reason, it is assumed that the original content is not encrypted, and digital license information including only a license header described later is added.

Publicly copied content refers to content copied by a person who has the right to sell the content. The publicly copied content is attached with digital license information to which a digital signature is added to prove the sales right at the same time that the content is encrypted.

Privately copied content refers to content copied by a person who does not have the right to sell the content. The privately copied content is attached with digital license information to which the content is encrypted and at the same time a digital signature is not added.

Next, a specific structure of the digital license information will be described. As shown in FIG. 1, the digital license information Lo includes a license header (LH), a content key (Kc), a content usage condition (U), an authenticator (MAC), and a digital signature.

As shown in FIG. 3, the license header is fixed-length data including license information length, content identifier (ID), copy information, and content key length. The length of the license information indicates the entire length of the license information and is used when extracting the license. The copy information is information for distinguishing whether the content is original content, public copy content, or private copy content.

The length of the content key indicates the length of the content key included in the license information.

The content use condition U in the digital license information indicates the use condition of the content corresponding to the digital license information, and is configured as shown in FIG. In FIG. 4, when the digital output flag Fe is “1”, digital output of the content is permitted, and when it is “0”, it is not permitted. The expiration date information indicates the expiration date of the content. Similarly, the effective count specifies the number of times the content can be used. These are all fixed length data defined by the system.

The digital license information shown here is only an example, and can be changed variously depending on the application form.

The authenticator is data for checking whether the content key and content usage conditions included in the digital license information are correct, and has the effect of error detection and falsification prevention.

As shown in FIG. 6, the digital signature is composed of a digital signature header and a digital signature. As shown in FIG. 7, the digital signature header is composed of the overall length (bit length) of the digital signature, the type of the digital signature, and the signature verification key number.

Since the digital license information Lo includes the content key Kc, it must be encrypted. However, on the other hand, if all the digital license information is encrypted, it must be decrypted even for the purpose of obtaining duplicate information, or even the original contents that do not need to be encrypted are encrypted. Need arises. In order to avoid this, in the present embodiment, as shown in FIG. 2, a configuration is shown in which the range of encryption is limited to the content key, the content use condition, and the authenticator. As shown in Figure 2,
Hereinafter, data obtained by encrypting the information I with the key K will be expressed as I [K] or [K] I. Also, it is assumed that common key encryption is used for digital license information and content encryption. Common key encryption is an encryption method in which an encryption key and a decryption key match. In the following embodiments, there is a description of encryption with a decryption key or decryption with an encryption key in context, but this is not contradictory for the above-described reason.

The encrypted digital license information has a structure as shown in FIG. 2, and a portion excluding the license header and the digital signature is encrypted with a license key described in detail later.

Next, analog license information will be described. The analog license information is embedded in the content itself as a digital watermark, and is embedded in the reproduced analog content. Therefore, even if the copyright protection of the content by encryption is broken, it is still effective. But on the other hand, because information is embedded in the content itself,
There is a drawback that embedding takes time.

Therefore, in the present embodiment, a structure as shown in FIG. 5 is considered as analog license information. That is, the analog license information 1 includes copy number limit information and copy information. The copy number limit information represents the upper limit (including unlimited) of the copy number of the content, and the copy information is included in the license header LH of FIG. Contains the same information as the copied information.

(First embodiment)
In the first embodiment, a content playback apparatus that determines whether input content is original content, private copy content, or public copy content based on the license information and changes the content playback method accordingly is described. To do.

FIG. 8 shows an overall configuration diagram of the content reproduction apparatus according to the present embodiment, and FIG. 12 shows a flow of processing. Hereinafter, the content reproduction apparatus of FIG. 8 will be described with reference to the flowchart of FIG.

First, in response to a playback instruction from the playback IF unit 3, the content C and the encrypted digital license information L are input to the content input unit 2 (step S1). These pieces of information are sent to the overall control unit 1, and here, referring to the license header of the encrypted digital license information, it is identified whether the content is original content, private copy content, or public copy content (step S2 to step S4), and according to the identification result, the reproduction processing of the original content, the reproduction processing of the private copy content, and the reproduction processing of the public copy content are performed (step S6 to step S8).

Since the contents that do not correspond to these three types of contents are contents that cannot be interpreted by the content reproduction apparatus of the present invention, an error is output and the process is terminated (step S5).

Reproduction processing for each content corresponding to the three types is performed in the respective reproduction units in FIG. Although these specific configurations and processing flows will be described later, it is important to adopt a configuration in which content does not flow from the private copy content reproduction unit 4 to the digital output unit 7. In other words, playback of privately copied content is permitted only for the purpose of private use, and there is a high possibility of deviating from the scope of private use for secondary use such as cutting and pasting part of the content. It is difficult to permit as a content supplier. In view of this point, the present invention provides a structural difference in the reproduction method between privately copied content, publicly copied content, and original content, and prevents the expansion of private use while permitting private copying. Protects content suppliers.

FIG. 9 shows a configuration diagram of the original content reproduction unit 6 in FIG. 8, and FIG. 13 shows a flow of the processing. As described above, original content refers to content that is not encrypted. Regarding license information, in this embodiment, digital license information is set only for the license header, and analog license information is set with an unlimited number of copies.

The original content playback unit 6 in FIG. 9 will be described below with reference to the flowchart in FIG.

The original content is input to the content input unit 6c (step S21).
Then, the data decompression unit 6f decompresses the compression format such as MPEG (step S22).
The digital content C output as a result is converted from a digital signal to an analog signal (D / A conversion) by the D / A converter 6g (step S23). When the analog license information detection unit 6d detects the analog license information embedded in the content (step S24), the control unit 6a refers to the copy information in the content, so that the content is the original content. Whether or not (step S25). If it is not the original content, an error is output at that point and the process is terminated (step S29). If it is an original content, if an instruction for digital output has been received (step S26), digital output is made via the digital output unit 6e (step S30), otherwise,
The digital content C is converted from a digital signal to an analog signal by the D / A conversion unit 6g and output via the analog output unit 6h (steps S27 to S28).
).

FIG. 10 shows a configuration diagram of the privately copied content playback unit 4 in FIG. 8, and FIG. 14 shows the processing flow. Private copy content refers to content that is encrypted and does not have a digital signature (certifying that it is a public copy) in the digital license information, as described above.

Hereinafter, the privately copied content reproduction unit 4 in FIG. 10 will be described with reference to the flowchart in FIG.

The privately copied content is input to the encrypted content input unit 4b together with the encrypted digital license information L (step S31). These pieces of information are sent to the encrypted content decrypting unit 4c, where the encrypted digital license information is decrypted by a process described in detail later (step S32), and the encrypted content is converted using the content key Kc included in the digital license information. Decrypt. Further, the use condition U is extracted from the digital license information (steps S33 to S35).

The control unit 4a checks the use condition U (step S36), and if it is determined that the use is not possible, an error is output and the process ends (step S42). If it can be used, it is further checked whether or not the condition described in the use condition deviates from the range (upper limit value) permitted for the privately copied content. If there is a deviation, the condition is set to the upper limit value, and the process proceeds to step S37. In this way, the system can cope with forgery of license information.

The control unit 4a sends the decrypted content C to the data decompression unit 4d, and MPEG
And the like, and the digital content Cd is output (step S37).
). After the digital content Cd is converted from a digital signal to an analog signal by the D / A converter 4e (step S38), the analog license information detector 4
f detects analog license information embedded in the content (step S).
39). Then, the control unit 4a determines whether or not the content is a private copy content by referring to the copy information in the analog license information (step S40). If it is not a private copy content, an error is output at that point and the process is terminated (step S43). D / A for privately replicated content
The converter 4e performs D / A conversion, and performs analog output via the analog output unit 4g (step S41). Note that digital output is not performed even if an instruction for digital output is received.

FIG. 11 shows a configuration diagram of the publicly duplicated content playback unit 5 in FIG. 8, and FIG. 15 shows the flow of the processing. As described above, the publicly copied content is encrypted and refers to content in which a digital signature (certifying that the copy is public) is added to the digital license information.

Hereinafter, the publicly copied content reproduction unit 5 of FIG. 11 will be described with reference to the flowchart of FIG.

The publicly copied content is input together with the encrypted digital license information to the encrypted content input unit 5b (step S51). These pieces of information are sent to the encrypted content decrypting unit 5c, where it is verified whether a digital signature is added to the encrypted digital license information by a process described in detail later, and if added, a digital signature verification key is used. The digital signature is used to verify the public copy (step S52 to step S53). Step S
If the digital signature has not been added in step 52, or if the digital signature cannot be verified in step S53, an error is output and the process ends (steps S64 to S65).

If the digital signature can be verified in step S53, the encrypted digital license information is decrypted by a process described in detail later (step S54), and the encrypted content is decrypted using the content key Kc included in the digital license information. Further, the use condition U is extracted from the digital license information (steps S55 to S55).
Step S57).

The control unit 5a checks the use conditions (step S58), and if it is determined that the use is not possible, an error is output and the process ends (step S66). If it can be used, it is further checked whether or not the condition described in the use condition deviates from the range (upper limit value) permitted for the privately copied content. If there is a deviation, the condition is set to the upper limit value, and the process proceeds to step S59. In this way, the system can cope with forgery of license information.

The control unit 5a sends the decrypted content C to the data decompression unit 5d, and MPEG
And the like, and the digital content Cd is output (step S59).
). After D / A conversion is performed on the digital content Cd by the D / A conversion unit 5e (step S60), the analog license information detection unit 5f detects an analog license embedded in the content. Then, the control unit 5a determines whether or not the content is a publicly copied content by referring to the copy information in the analog license information (step S61). If it is not a publicly copied content, an error is output at that point and the process ends (step S67). If it is a publicly copied content, if a digital output instruction has been received (step S6)
2) Digital output is performed via the digital output unit 5i (step S68). Otherwise, D / A conversion is performed by the D / A conversion unit 5e, and analog output is performed via the analog output unit 5g (step S63).

Next, the encrypted content decrypting unit will be described. This component is present in the private copy content playback unit 4 and the public copy content playback unit 5, both of which are similar in configuration. First, the encrypted content decrypting unit 5c of the publicly duplicated content playback unit 5 will be described, and only the difference between the encrypted content decrypting unit 4c of the privately replicated content playback unit 4 and the encrypted content decrypting unit 5c will be described. .

A configuration example of the encrypted content decrypting unit 5c is shown in FIG. 16, and a flow of the processing is shown in FIG. Hereinafter, the encrypted content decrypting unit 5c will be described with reference to the flowchart of FIG.

When the encrypted content Kc [C] and the encrypted digital license information L are input to the encrypted license decryption unit 5c (step S71), the encrypted license decryption unit 5c includes a media ID extraction unit (public duplicate content reproduction unit 5). In the case of the media ID extraction unit 5h, and in the case of the private copy content playback unit 4, the media ID that is the identifier of the medium M on which the content is recorded is acquired through the media ID extraction unit 4h) (step S72). . Using the media ID, a license decryption key w is created by means described in detail later, and the decrypted digital license information is output (step S73).

Among the digital license information shown in FIG. 1, an authenticator is calculated from the content key Kc and the content usage condition U (step S75). The authenticator is, for example, information obtained by connecting a content key and a content usage condition as a value output as an input of a one-way function.

The role of the authenticator here is a role of error detection that prevents the wrong content decryption key and usage conditions from being output because the license key w is wrong. The generation of the MAC is realized by a one-way function. The one-way function is realized by a hash function or a cryptographic function, and refers to a function in which an input value cannot be estimated from an output value.

The MAC verification unit 102 includes an authenticator calculated from the output from the encrypted license decryption unit 101, and an authenticator MAC included in the digital license information of FIG. (Step S76), and if the content matches, the output content decryption key Kc can be trusted (step S77), and the content decrypting unit 103 decrypts the encrypted content using this Kc (step S78). ). If the authenticators do not match, an error is output and the process ends (step S81).

If the authenticator is collated and the encrypted content can be decrypted, the content C and the usage rule U are output, and the processing of the encrypted content decrypting unit is terminated (step S79).

Next, the encrypted license decryption unit 10 which is a component of the encrypted content decryption unit.
1 will be described in detail. FIG. 17 shows the configuration, and FIG. 19 shows the processing flow.

Hereinafter, with reference to the flowchart shown in FIG.
1 will be described.

When the encrypted digital license information L is input (step S91), first, the digital signature detection unit 101a detects the digital signature (step S).
92). That is, digital signature detection uses data in the license header,
For example, the start address of the digital signature is calculated using the following equation.

Start address of digital signature = Start address of encrypted digital license information + (License header length + Content key length + Content usage condition length + Authentication length)
The digital signature verification key acquisition unit 101b acquires a fixed-length digital signature header from the head address of the digital signature (see FIGS. 6 and 7), and the total length of the digital signature, the type of signature, The signature algorithm and its verification key can be specified from the number of the signature verification key. When the signature type and signature verification key number are obtained, the digital signature verification key holding unit 101f is searched based on the signature type and the signature algorithm and verification key corresponding to the signature type and signature verification key number. get(
Step S94).

If the digital signature (header) cannot be detected, an error is output and the process ends (steps S93 and S101).

If the digital signature is detected, the digital signature verification unit 101c next verifies the detected digital signature using the signature algorithm specified by the digital signature header and the signature verification key of the signature verification key number (step). S95).

The digital signature here is based on public key cryptography. That is, only an authorized server or a store having a signature creation key (secret key) can create a license file corresponding to publicly copied content. Even if the other person owns the playback device, only the signature verification key (public key) is in it, and it is difficult to obtain the private key from the public key. Therefore, if sufficiently secure public key cryptography is used, a third party who does not know the secret key cannot create a digital signature corresponding to the license. This leads to an authorized merchant being able to create a license for publicly copied content. However, public key cryptography is not always safe due to the development of attack methods (decryption methods). In view of this point, the configuration is such that the signature algorithm and signature verification key are designated in the header of the digital signature and can be changed at any time on the server side.

If the digital signature verification unit 101c determines that the signature verification result is NG, an error is output (step S96, step S102). Otherwise, the license key generation unit 101d acquires the media ID (MID) of the media on which the encrypted content is recorded (step S97), and uses this function that is secretly stored in the playback device. And
w = f (MID)
The license key w depending on the medium is obtained from (step S98).

This is because when the content is transferred to another medium, that is, copied, only the license key w depending on the media can be obtained, so that the encrypted digital license information cannot be decrypted, and as a result, the content cannot be decrypted. It is a mechanism.

Thus, whether it is a private copy or a public copy, the encrypted digital license information must be recreated for copying, and only a valid recording device that knows the function f can do so. Therefore, unauthorized use can be prevented because the number of copying can be surely restricted. In this sense, it is desirable that the hardware or firmware for realizing the function f exists in a tamper-resistant LSI.

The license decryption unit 101e decrypts the encrypted digital license information using the license key w created in this way (step S99), obtains the digital license information Lo, and outputs it (step S100).

The above is the description of the encrypted content decrypting unit 5c of the publicly copied content reproduction unit 5 and the encrypted license decrypting unit 101 that is a component thereof. Note that the encrypted license decryption unit 10 of the encrypted content decryption unit 4c of the private copy content playback unit 4
1 is a digital signature detection unit 101c and a digital signature verification key acquisition unit 101 in FIG.
b, the digital signature verification key holding unit 101f and the digital signature verification unit 101c are not necessarily required as components, and their processing is not necessary.

Next, some variations on the content reproduction apparatus described above will be described.

First, in the overall configuration of FIG. 8, a form in which the playback unit is completely separated depending on the type of content is shown, but this is not always necessary. In practice, it is divided according to the type of license file, and there are many parts that are similar in processing as described above. For this reason, the circuit scale can be reduced by making the same processing portion into one circuit. On the other hand, even if the circuit has the same function, safety can be improved by changing the specifications for each playback unit. For example, in the data decompression unit (4d, 5d, 6f) of each playback unit, it is more difficult to fake the content type by the license information by using different algorithms for each content type.

  A configuration of a playback device that does not have an original content playback unit is also conceivable.

In this case, the original content cannot be played back on the playback device side, and the content is limited to two of publicly copied content and privately copied content.

By doing so, there is a problem that even self-made content is regarded as privately copied content. On the other hand, problems such as dubbing content from radio and television that are not self-produced content and recorded as original content can be avoided.

Further, in addition to adding the digital signature in the form of FIG. 1, as shown in FIG. 20, after encryption with the license key w, re-encryption with the signature generation key Ks may be performed. In this way, it can be configured such that it cannot be correctly decrypted even if it is encrypted with a different signature generation key or decrypted with a correct signature verification key. Whether or not the decryption has been correctly performed can be reliably determined by the authenticator MAC. By doing so, the data size for the digital signature can be reduced.

(Second Embodiment)
Here, a content recording apparatus capable of producing original content or privately copied content from self-made content and privately copied content from publicly copied content will be described.

The present embodiment is a recording apparatus corresponding to the playback apparatus of the first embodiment described above, and can be integrated with the playback apparatus to constitute a content recording / playback apparatus.

The overall configuration of the content recording apparatus according to the present embodiment is shown in FIG. 21, and the processing flow is shown in the flowchart of FIG. Hereinafter, the content reproduction apparatus of FIG. 21 will be described with reference to the flowchart of FIG.

In the content input unit 202, content encrypted as content (K
c [C]) or unencrypted content C is encrypted license information L
It is input together (step S201).

The overall control unit 201 refers to the license header of the encrypted digital license information and if the content is a publicly copied content (step S202),
These data are sent to the private duplicate content creation unit 204, and the process proceeds to the private duplicate content creation process (step S203).

If the content is a private copy content (step S204), these data are sent to the private copy content creation unit 204, and the process proceeds to the private copy content creation processing (step S205).

If the content is the original content (step S206), these data are sent to the original content creation unit 205, and the original content creation process is started (step S207).

In this way, by changing the recording means depending on the type of content and providing an environment where the recording device can only perform private copying at most, differentiated publicly copied content and privately copied content on the official sales channel, By relatively increasing the value of publicly replicated content, it contributes to the expansion of the market for publicly replicated content.

Next, the private copy content creation unit 204 of the content recording apparatus in FIG. 21 will be described in detail. FIG. 22 shows a configuration example of the private copy content creation unit 204, and FIGS.

Hereinafter, the private copy content creation unit 204 will be described with reference to the flowcharts shown in FIGS.

When copying privately copied content, first, the encrypted content Kc [C], the encrypted digital license information L, and the copy form information Q are input from the content input unit 204b, and the process is started (step S211). ).

The copy form information Q has a structure shown in FIG. That is, the copy form information Q
Describes the content type after duplication (duplication content type) and the usage conditions (usage condition information) of the duplicate content.

Here, the usage condition information has the configuration shown in FIG. 31, and includes a digital output flag, expiration date information, effective usage count information, and copy count limit information, which are described in the digital license information and analog license information, respectively. It is information to embed in existing information.

As will be clear from the following processing, depending on the content type after copying,
Such information is not necessarily reflected as it is. As will be described later, this is because each upper limit value is defined by the content type after copying, and it is not allowed to set the upper limit value. In this way, a private copy content, a public copy content, and an original content are distinguished from each other in use, and a system that is in the interest of the content supplier is realized.

The inputted encrypted content Kc [C], the encrypted digital license information L, and the copy form information Q are sent to the control unit 204a, and the encrypted content Kc [L] and the encrypted digital license information are sent. L is sent to the content decryption unit 204e.

The content decrypting unit 204e decrypts the encrypted content in the same manner as the content playback of the content playback device of the first embodiment. That is, a media ID (MID) is acquired from the source-side media M via the media ID acquisition unit 206 (step S212), and the media ID and the secret function f are used,
w = f (MID)
The license key w is created from the relational expression (step S213), and the encrypted digital license information L is decrypted (step S214). The content decryption key Kc is extracted from the decrypted digital license information (step S215). Further, the authenticator is extracted from the digital license information and checked to confirm that there is no error in the content decryption key Kc (step S216). Then, the encrypted content is decrypted using the content decryption key Kc to obtain the content C (step S218).

The content C decrypted by the content decryption unit 204e is sent to the analog license detection / correction unit 204f via the control unit 204a. Here, first of all
The content C is sent to the data decompression unit 204g, the compression of the content C is decompressed (step S219), D / A conversion is performed on the decompressed digital content C (step S220), and the analog content Ca is obtained. Analog license information is extracted from the analog content Ca (step S221), and the type of the content is specified based on the copy information of the analog license information.

When the content of the source is publicly copied content (step S22)
2) The copy information of the analog license information as shown in FIG. 5 is corrected to the private copy content (step S226), and the copy number limit information of the analog license information is also set to the upper limit allowed for the private copy content. (Step S227
).

On the other hand, if the content of the source is a private copy content (step S2
23), the copy number limit information of the analog license information as shown in FIG.
Is subtracted (step S224).

If the source content is neither publicly copied content nor privately copied content, an error is output (step S228).

The analog license information currently recorded is deleted from the analog license information created by the above processing, and is embedded in the analog content (step S22).
5). Further, after A / D conversion and conversion into digital content Cd (step S229), the data is sent to the data compression unit 204h for compression processing (step S23).
0) New content C is obtained.

The new content C is transferred from the analog license information detection / correction unit 204f to the content encryption unit 204d via the control unit 204a.
Sent with.

The content encryption unit 204d encrypts the input content C with the input content decryption key Kc, and obtains the encrypted content Kc [C] (step S231).

On the other hand, the control unit 204a refers to the digital output flag, the expiration date information, and the effective use frequency limit described in the use condition information of the copy form information Q, and these conditions deviate from the scope of the private copy content. Make sure there is no. If the content has deviated, the content usage condition U included in the digital license information is created within the range permitted for the privately copied content (step S232).

Next, an authenticator (MAC) is obtained from the content decryption key Kc and the content usage condition U.
Is calculated (step S233). The calculation method is the same as the calculation performed for authenticator confirmation in the content reproduction apparatus of the first embodiment described above.

Further, information indicating that the content is a private copy content and the like are calculated and stored in the copy information portion of the license header, and the digital license information of the content is completed.

Next, in order to encrypt the digital license information, a media ID (MID) is acquired from the target side (recording side) medium M ′ through the media ID acquisition unit 206 (step S235). From the acquired media ID (MID) w = f (MID)
To generate a license key w (step S236). This generation method is the same as the license key creation method created for the encrypted digital license information L described in the processing section of the content decryption unit 204e. However, since the MID is different from the former case, a different license key is generated.

By changing the data of the encrypted digital license information before and after copying in this way, unauthorized copying can be prevented.

Using the license key w obtained in step S236, the digital license information Lo is encrypted to obtain encrypted digital license information L (step S237).
.

All the data to be recorded is thus completed, and the encrypted content Kc [C] and the encrypted digital license information L are recorded on the target-side medium M ′ through the content recording unit 208 and the license recording unit 207, respectively (step S2).
38-step S239).

Next, the original content creation unit 205 in the content recording apparatus of FIG.
Will be described in detail. The configuration of the original content creation unit 205 is shown in FIG. 23, and the processing flow is shown in FIGS.

The original content creation unit 205 in FIG. 23 will be described below with reference to the flowcharts shown in FIGS.

When copying the original content, first, the content C and the copy form information Q are input from the content input unit 205b, and the process is started (step S241).
).

The content C is sent to the analog license information detection / correction unit 205d via the control unit 205a, and the content is decompressed by the processing of the data decompression unit 205g (step S242).

D / A conversion is performed on the decompressed digital content Cd to detect analog license information (steps S243 to S244). If it is the original content, it should not be detected, but if the content is falsified as the original content by falsifying a part of the data, an error is output here, and the process ends ( Step S245 to Step S246).

If it is the original content, it is determined from the copy content type of the copy form information Q whether the copy destination is the original content or the private copy content (step S247).

Since the original content is copyrighted content for the user as defined above, the original content can be copied to original content that is not encrypted or privately copied content. Naturally, it can be reproduced under more advantageous conditions if it is copied to the original content. However, if the author himself wants to place some restrictions on the usage form at the copy destination, the purpose is realized by recording it as a private copy content.

If it is desired to duplicate as privately duplicated content, it is necessary to proceed to step S248 and record analog license information in the content. For this reason, analog license information is created, the copy information is privately copied, and the copy number limit exceeds the upper limit of the number of copies permitted for privately copied content. Set within a range, the analog license information is embedded in the content C, A / D converted, and further compressed by the data compression unit 205h to obtain new content C (steps S248 to S25).
2).

On the other hand, when copying as original content, the process proceeds from step S247 to step S251, A / D conversion is performed without modifying analog license information, and compression processing is performed to obtain content C (step S25).
1-step S252).

The content C created by the above processing is the analog license information detection / correction unit 2.
05d is sent to the control unit 205a, and the processing procedure is changed depending on whether the control unit 205a refers to the copy form information Q and copies it to the private copy content or the original content (step S253).

First of all, if you are copying to the original content, you do not need to encrypt it,
The license generation unit 205c creates only the license header for the digital license information, sets the copy information in the license header as “original content” (step S264), and records the digital license information on the target side media through the license recording unit 207. (Step S262). Here, since the digital license information in the case of the original content has only the license header, there is no encrypted part and it is not necessary to create a license key. Content C
Since it does not need to be encrypted, the content is recorded on the target medium through the content recording unit 208 as it is (step S263).

Next, processing for recording as privately copied content will be described. When recording as privately copied content (step S253), the content C must be encrypted, and the encrypted digital license information L including the content decryption key Kc corresponding to the content must be created and recorded on the medium. Don't be. The procedure will be described sequentially.

The control unit 205a sends the content C to the content encryption unit 205e, and the content encryption unit 20e issues a command to the content decryption key generation unit 205f to generate the content key Kc (step S254). The content C is encrypted with the created content decryption key Kc (step S255), and the encrypted content Kc
[C] is obtained. The encrypted content Kc [C] is transferred to the content recording unit 208 and recorded on the target-side medium (step S263).

On the other hand, the content decryption key Kc is once transferred to the control unit 205a and then to the license generation unit 205c. In the license generation unit 205c, the media ID
The media ID (MID) of the target side media is acquired from the acquisition unit 206 (
Step S256),
w = f (MID)
Thus, the license key w is created (step S257).

Further, the content usage condition U included in the digital license information is determined within the range permitted for the private copy content with reference to the usage condition information of the copy form information Q (step S258).

Next, an authenticator (MAC) is generated from the content key Kc and the usage rule U (step S259). Thus, the digital license information Lo is generated (step S260), and the digital license information is encrypted using the previously generated license key w to obtain the encrypted digital license information L (step S261).

The obtained encrypted digital license information L is recorded on the target-side medium by the license recording unit 207 (step S262).

  This is the end of the description of the content recording apparatus.

Next, some modified examples (third to sixth embodiments) of the second embodiment will be described.

(Third embodiment)
When copying non-original content (especially publicly copied content)
In the private copy content creation unit 204, it is desirable to moderately degrade the content. This is because the expectation for duplication is reduced due to deterioration, and sales of publicly duplicated content on the official sales channel are promoted. In this sense, the analog license information detection / correction unit 204f may be configured to realize this depending on whether noise is added to the content or the compression rate in data compression is increased. For this purpose, a method of adjusting the compression rate of the data compression unit 204h so as to cause deterioration, or a method of extremely embedding when embedding analog license information to a level where deterioration of content occurs can be considered. Particularly in the latter case, there is an advantage that the analog license information is difficult to peel off.

(Fourth embodiment)
A recording device (or recording / reproducing device) that does not accept original content as a content type is also conceivable. For example, such an apparatus may omit the original content creation unit 205 in the configuration of FIG. 21 and omit the processing related to input of the original content and copying of the original content in the above description.

Conversely, at least when input of original content is permitted, a method of limiting input terminals permitted as original content is conceivable. According to this method,
For example, audio input from a microphone terminal can be recorded as original content, but audio input from a radio terminal can be recorded as private copy content, and the type of copy content is determined by the input medium. It is possible not only to record even if it is not input in the format of the recording apparatus, but also to distinguish whether the copy is from the original content or not.

(Fifth embodiment)
Although the content playback apparatus of the first embodiment and the content recording apparatus of the second embodiment have independent mechanisms, it is also possible to consider an integrated form of the recording / playback apparatus. In this case, it is possible to share a media ID acquisition unit, a data compression unit, a data decompression unit, and the like, which are components having the same function.

(Sixth embodiment)
There is a form in which the source content to be recorded is limited to analog only and can only be copied to privately copied content. In this way, when recording digital content, the quality of the content can be degraded by going through the analog layer once, and the same level of quality degradation as conventional private copying is realized, Private reproduction on the quality of content can be realized.

FIG. 32 shows the configuration of such a content recording apparatus, and FIG.
As shown in FIG.

The content recording apparatus in FIG. 32 will be described below with reference to the flowcharts shown in FIGS.

Analog content Ca is input from the content input unit 301 (step S301). The input analog content Ca is sent to the analog license information detection / correction unit 302, where the analog license information is extracted (step S302), and it is confirmed that the copy number limit included in the analog license information is “1” or more. (Step S303). If not, no more copies can be generated and an error is output (step S304).

Hereinafter, it is assumed that the analog license information does not exist or the copy number limit is “1” or more. When there is no analog license information, the copy number limit is set to the upper limit of private copy content. If there is, the copy number limit is decremented by "1". In either case, copy information is set to private copy content. After creating the license information and removing the analog license information if it already exists, the newly created analog license information is embedded in the content (step S3).
05 to step S306).

The content Ca in which the analog license information is embedded is the A / D conversion unit 303.
Is converted to digital content Cd (step S307). The digital content Cd is sent to the data compression unit 305 to create the compressed content C (step S308).

The content C is sent to the content encryption unit 307 via the overall control unit 304, and the content encryption unit 307 encrypts the content C using the content decryption key Kc generated by the content key generation unit 309. Encrypted content K
c [C] is created (steps S309 to S310).

On the other hand, the content encryption unit 307 receives the content decryption key Kc from the overall control unit 30.
4 and the license generation unit 30 together with the usage conditions U determined by the overall control unit 304.
Send to 6.

The license generation unit 306 generates an authenticator (MAC) from the content decryption key Kc and the usage rule U, and creates digital license information Lo. The generated digital license information Lo is sent to the license encryption unit 308, and the license encryption unit 308 encrypts the digital license information Lo using the license key w generated by the license key generation unit 310 (step S311). ~ Step S3
14).

Here, a processing flow of the license key generation unit 310 will be described. The license key generation unit 310 acquires the media ID (MID) of the media that records the encrypted content via the media ID acquisition unit 312 (step S312).
w = f (MID)
Thus, the license key w is generated (step S313).

The encrypted digital license L is recorded on the media via the license recording unit 311 (step S315). Similarly, encrypted content Kc [C]
Is also recorded on the medium (step S316).

By integrating the playback apparatus that does not allow the original content described in the first embodiment with the recording apparatus of the present embodiment or using it as a pair, a content recording / playback apparatus with higher security can be created. In other words, when inputting and recording content from other than the recording / reproducing apparatus of the present invention, only analog input is allowed, and recording of digital content is limited to privately copied content. This means that even in the world of digital recording and reproduction, since it goes through analog once, quality improvement over conventional recording and reproduction systems cannot be expected. The value of the publicly duplicated content can be relatively increased, and the sales market for the publicly duplicated content can be secured more reliably.

(Seventh embodiment)
In the present embodiment, a content selling apparatus and a content purchasing apparatus used when purchasing and reproducing digital content will be described. Here, for example, one form of a mechanism for purchasing / selling digital contents via an Internet server or a vending machine is shown.

First, an embodiment of a content sales apparatus will be described. A content sales apparatus refers to a sales apparatus that creates and sells publicly copied content in response to a purchase request. In the present embodiment, it is assumed that the content sales server apparatus is established by an electronic store realized on a network.

35 is an overall configuration diagram of the sales server, and FIG. 36 is a license generation unit 4 in FIG.
FIG.

First, a description will be given with reference to FIGS. 37 and 38 showing the flow of the entire processing of the sales server.

The sales server starts the operation by receiving the content purchase request from the client (step S401). As shown in FIG. 39, the purchase request information includes the ID information of the customer who applied for purchase and the content ID (CI) of the content to be purchased.
D), purchase usage conditions, (Uc), media ID (MID) of the recording medium on which the customer records content, and client address.

Upon receiving the purchase request information, the sales server sends this to the overall control unit 402,
The content ID included in the purchase request information is sent to the content search unit 405,
The content database (DB) 407 is searched to extract the content decryption key Kc and the sales amount P (and possibly the encrypted content Kc [C]) (step S402).

Here, as a condition for extracting the encrypted content Kc [C], for example, if the content ID is expressed by a sufficiently large number of bits and there are redundant bits, one bit of the redundant bits is transmitted as the encrypted content. It can be used as a determination flag for determining whether or not to perform.

Next (or at the same time as the processing in the content search unit 405), the overall control unit 402 uses the customer ID as a key and the customer credit number as a customer database (DB).
A search is made from 408 and a credit inquiry is performed with the searched credit number (step S).
403 Step S404). If payment as a result of the credit inquiry is possible, encrypted digital license information is generated according to the procedure described in detail below, and the encrypted digital license information is output to the client address (steps S405 to S407). If payment is not possible as a result of the credit inquiry, this is notified to the client address. Notification and output may be performed by e-mail, or when a direct network connection is used, the connected network may be used.

Next, the encrypted digital license information generation process of the license generation unit 403 in FIG. 36 will be described with reference to the flowchart shown in FIG.

The license generation unit 403 starts processing upon receiving the input of the content decryption key Kc output from the content DB 407 and the media ID (MID) extracted from the purchase request information (step S411).

First, the usage rule U input by the control unit 403b in the license generation unit 403 is determined, an authentication code (MAC) is generated from the content decryption key Kc and the usage rule U, and digital license information Lo is generated (step S1). S412-step S
413).

Next, from the input media ID (MID), w = f (MID)
To generate a license key w (step S414). The license key generation unit 403c transmits the license key w and the digital license information Lo to the control unit 403b.
The control unit 403b generates encrypted digital license information by encrypting the license information Lo (steps S415 to S416).
).

Further, the key server secret key Ks and the ID (KID) of the secret key are extracted from the server secret key database (DB) 409 (step S417), and the encrypted license information L is digitally signed with the secret key Ks (step S417). S418), the encrypted license L is created by adding this. And the created digital license information L
Is output to end the process (step S419).

Here, the digital signature is created by public key cryptography, and the data shown in FIGS. 6 and 7 is created. The total length of the digital signature included in the digital signature header is the length of the digital signature including the header, the signature type is the identifier of the signature scheme type, and the signature verification key number is the secret key ID (KID). Enter each.

This is the end of the description of the content sales apparatus, that is, the sales server.
The mechanism of the content purchase apparatus corresponding to sales will be described. The content purchase device may be a playback device itself, but is not necessarily required, and may be a device such as a personal computer that can be connected to a network or a dedicated device.

FIG. 40 shows the configuration of the content purchase apparatus, and the content purchase apparatus will be described below with reference to the flowcharts shown in FIGS.

The content purchase apparatus receives the content ID of the content to be purchased through the content selection interface (IF) 501 and sends it to the overall control unit 502 (step S501). The content selection IF 501 may be in a form in which a content ID is input from a keyboard, or may be input by a user searching for and specifying a singer name, composer, or the like with dedicated search software or input software.

In response to the input of the content ID, the overall control unit 502 extracts the media ID (MID) from the media on which the content is recorded (or already recorded) via the media ID extraction unit 504 (step S502). .

Next (or at the same time), from the customer information holding unit 505 (customer's) customer ID,
A customer address is extracted (step S503), and based on the extracted information, FIG.
The purchase request information as shown in FIG. 9 is transmitted to the sales server (steps S504 to S505).

In the present embodiment, customer information is stored in the customer information holding unit 505, but the same processing can be performed even if this part is changed to input from the outside.

Further, according to the purchase request information, the content sales device sends an encrypted license L (if there is no encrypted content on the content purchasing device side, encrypted content Kc [C
] Are recorded on the media from which the media ID is extracted (steps S511 to S512).

This is the end of the description of the configuration of the content purchase apparatus and the flow of processing. It can be seen from the above configuration that the content purchase apparatus can be integrated with the content reproduction apparatus. That is, the configuration of the playback device shown in FIG. 8 is functionally independent of the configuration of the sales client shown in FIG. 40, and a device having both functions can be configured. Similarly, the same relationship holds with the content recording / reproducing apparatus described in the second embodiment.

For this reason, a system in which the content sales apparatus and the content purchase apparatus are integrated is also conceivable. This is a device like a vending machine for content information, and FIG.
The billing unit 404 in the configuration of the content sales apparatus 5 is changed to a coin /
This can be realized by using the bill detection and storage device and recording the created encrypted license L (and encrypted content) on the media via the media recording unit 503 in the configuration of the content purchase device of FIG.

By realizing such a vending machine, a customer can bring media to the vending machine and purchase content and a license. Of course, a vending machine can be configured with a content purchasing apparatus alone. In that case, it must be connected to the content sales apparatus via a telephone line or the like.

The figure which showed an example of the data structure of digital license information. The figure which showed an example of the data structure of encryption digital license information. The figure which showed an example of the data structure of a license header. The figure which showed an example of the data structure of content usage conditions. The figure which showed an example of the data structure of analog license information. The figure which showed an example of the data structure of a digital signature. The figure which showed an example of the data structure of a digital signature header. The figure which showed the structural example of the content reproduction apparatus. The figure which showed the structural example of the original content reproduction part. The figure which showed the structural example of the private reproduction content reproduction part. The figure which showed the structural example of the public reproduction content reproduction | regeneration part. FIG. 9 is a flowchart for explaining a processing operation of the content reproduction apparatus of FIG. 8. The flowchart for demonstrating original content reproduction | regeneration processing operation | movement. The flowchart for demonstrating private reproduction content reproduction | regeneration processing operation | movement. The flowchart for demonstrating public reproduction content reproduction | regeneration processing operation | movement. The figure which showed the structural example of the encryption content decoding part. The figure which showed the structural example of the encryption license decoding part. The flowchart for demonstrating encryption content decoding processing operation. The flowchart for demonstrating encryption license decoding process operation | movement. It is the figure which showed the other example of encryption digital license information, and shows the case where a digital signature is not used. The figure which showed the structural example of the content recording device. The figure which showed the structural example of the private duplication content creation part. The figure which showed the structural example of the original content creation part. The flowchart for demonstrating the processing operation of the content recording device of FIG. The flowchart for demonstrating private copy content creation processing operation. The flowchart for demonstrating private copy content creation processing operation. The flowchart for demonstrating original content creation processing operation. The flowchart for demonstrating original content creation processing operation. The flowchart for demonstrating original content creation processing operation. The figure which showed an example of the data structure of duplication form information. The figure which showed an example of the data structure of the use condition information in duplication form information. The other example of a structure of a content recording device is shown, The case where the content to record is an analog signal is shown. The flowchart for demonstrating the processing operation of the content recording apparatus of FIG. The flowchart for demonstrating the processing operation of the content recording apparatus of FIG. The figure which showed the structural example of the content sales apparatus (sales server). The figure which showed the structural example of the license production | generation part of the content sales apparatus of FIG. The flowchart for demonstrating the processing operation of the content sales apparatus of FIG. The flowchart for demonstrating a license production | generation process operation. The figure which showed an example of the data structure of purchase request information. The figure which showed the structural example of the content purchasing apparatus. 41 is a flowchart for explaining the processing operation of the content purchase apparatus in FIG. 40. 41 is a flowchart for explaining the processing operation of the content purchase apparatus in FIG. 40.

Explanation of symbols

(Content playback device)
DESCRIPTION OF SYMBOLS 1 ... Overall control part 2 ... Content input part 3 ... Playback interface (IF) part 4 ... Private reproduction content reproduction part 5 ... Public reproduction content reproduction part 6 ... Original content reproduction part 7 ... Digital output part 8 ... Analog output part (Content recording device)
DESCRIPTION OF SYMBOLS 201 ... Overall control part 202 ... Content input part 203 ... Recording interface (IF) part 204 ... Private duplicate content creation part 205 ... Original content creation part 206 ... Media ID acquisition part 207 ... License recording part 208 ... Content recording part (content Sales equipment)
401 ... Content purchase acceptance unit 402 ... Overall control unit 403 ... License generation unit 404 ... Billing unit 405 ... Content search unit 406 ... Output unit 407 ... Content database (DB)
408 ... Customer database (DB)
409 ... Server private key database (DB)
(Content purchase device)
501 ... Content selection interface (IF)
502 ... Overall control unit 503 ... Media recording unit 504 ... Media ID extraction unit 505 ... Customer information holding unit 506 ... Content input unit

Claims (6)

In an information recording apparatus for copying content recorded on a first recording medium to a second recording medium,
Reading means for reading out the first digital content in which the first analog license information is embedded by electronic watermarking and the first digital license information for the first digital content from the first recording medium;
The first digital license information includes a digital signature that certifies that the type of the first digital content is publicly copied content, and the first digital copy information included in the first digital license information When the first digital content type indicates publicly copied content copied by a person with sales rights, the digital signature is not included and the content type is copied by a person without sales rights Generating means for generating second digital license information including second digital copy information indicating that the content is a dynamic copy content;
A DA converter that converts the first digital content, which is a digital signal, into first analog content, which is an analog signal;
Extracting means for extracting the first analog license information from the first analog content;
If the first analog copy information included in the first analog license information indicates that the type of the first digital content is a public copy content, a second analog indicating that the content type is a private copy content Second generation means for generating second analog license information including copy information;
An embedding means for embedding the second analog license information in the first analog content and generating second analog content;
An AD converter that converts the second analog content, which is an analog signal, into second digital content, which is a digital signal;
An information recording apparatus comprising: writing means for writing the second digital content and the second digital license information to the second recording medium. The first digital license information includes copy number limit information corresponding to the first digital content,
The second digital license information includes copy number limit information corresponding to the second digital content,
The first analog license information includes copy number limit information corresponding to the first digital content,
The second analog license information includes copy number limit information corresponding to the second digital content,
The first generation means changes the copy number limit information of the first digital license information so as to further limit, and generates copy number limit information of the second digital license information,
The said 2nd production | generation means changes so that the copy number restriction | limiting information of said 1 analog license information may be restrict | limited more, The copy number restriction | limiting information of said 2nd analog license information is produced | generated. The information recording device described. The first digital content is encrypted with a first content key;
The first digital license information further includes the first content key,
Of the first digital license information, the first content key is encrypted with at least the first license key,
The first license key is defined by a secret function f having the first media ID of the first recording medium as input.
Second reading means for reading the first media ID from the first recording medium;
First decryption means for decrypting the first content key using the first license key obtained by using a secret function f having the first media ID as an input;
Second decryption means for decrypting the first digital content using the first content key;
First encryption means for encrypting the second digital content using a second content key;
Third reading means for reading a second media ID from the second recording medium;
Second encryption for encrypting at least the second content key included in the second digital license information using a second license key obtained by using a secret function f having the second media ID as an input The information recording apparatus according to claim 1, further comprising: means. The first digital license information further includes a first use condition information indicating a use condition of the first digital content, a first authenticator for checking whether the first use condition information and the first content key are correct. Including
The first authenticator is defined by a second function that receives the first content key and the first use condition information,
Of the information included in the first digital license information, the first content key, the first use condition information, and the first authenticator are encrypted with the first license key,
After the first content key is decrypted by the first decryption means and before the first digital content is decrypted by the second decryption means, the second content key and the first use condition information are used to determine the second content key. The information recording apparatus according to claim 3, further comprising first calculation means for calculating whether or not the first authenticator can be calculated by a function. In an information recording apparatus for copying content recorded on a first recording medium to a second recording medium,
Reading means for reading out the first digital content and the first digital license information for the first digital content from the first recording medium;
The first digital license information includes a digital signature that certifies that the type of the first digital content is publicly copied content, and the first digital copy information included in the first digital license information When the first digital content type indicates publicly copied content copied by a person with sales rights, the digital signature is not included and the content type is copied by a person without sales rights Generating means for generating second digital license information including second digital copy information indicating that the content is a dynamic copy content;
An information recording apparatus comprising: writing means for writing the first digital content and the second digital license information to the second recording medium. In an information recording apparatus for copying content recorded on a first recording medium to a second recording medium,
Reading means for reading out the first digital content in which the first analog license information is embedded by electronic watermarking and the first digital license information for the first digital content from the first recording medium;
The first digital license information includes a digital signature that certifies that the type of the first digital content is publicly copied content, and the first digital copy information included in the first digital license information When the first digital content type indicates publicly copied content copied by a person with sales rights, the digital signature is not included and the content type is copied by a person without sales rights Generating means for generating second digital license information including second digital copy information indicating that the content is a dynamic copy content;
A DA converter that converts the first digital content, which is a digital signal, into first analog content, which is an analog signal;
Extracting means for extracting the first analog license information from the first analog content;
If the first analog copy information included in the first analog license information indicates that the type of the first digital content is a public copy content, a second analog indicating that the content type is a private copy content Second generation means for generating second analog license information including copy information;
An embedding means for embedding the second analog license information in the first analog content and generating second analog content;
An AD converter that converts the second analog content, which is an analog signal, into second digital content, which is a digital signal;
An information recording apparatus comprising: writing means for writing the second digital content and the second digital license information to the second recording medium.

Images