JP2002268951A - Recording medium and medium access controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording medium capable of preventing unauthorized use of recorded contents exceeding the expiration data by inexpensive structure. SOLUTION: In the recording medium 10 to record the contents with the set expiration data, it is provided at least with an oscillator 13, a counter 14 to be driven by rectangular waves to be generated by the oscillator, a power source 12 to supply drive current to the oscillator and the counter and a data holding means 15 to hold computerized data and computerized data of the expiration date in which the expiration data of the contents is expressed by a value of the counter and computerized data of the contents are stored in the data holding means. When the contents are read from the recording medium, the computerized data of the expiration date is compared with the current counter value of the counter in the recording medium, when the current counter value does not exceed the expiration date, the contents are outputted to the outside and when the current counter value exceeds the expiration date, the contents are not outputted to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium such as a memory card and a media access control device for accessing the recording medium, and more particularly, to setting an expiration date for contents recorded on the recording medium. Things.

[0002]

2. Description of the Related Art Conventionally, small memory cards of various shapes have been developed by various companies and sold under various trade names. Such recording media have begun to be used in many devices such as digital cameras and mobile phones as storage media having excellent portability. In addition, content such as distribution music is recorded on a recording medium, and the recording medium is mounted on a reproducing device to reproduce the content.

[0003] Further, from the viewpoint of copyright protection and the like, there has conventionally been an idea of setting an expiration date of content to be recorded on a recording medium and limiting a reproduction period of the content. A method has been considered in which a clock that measures time is installed, and the expiration date of recorded content is measured using the clock.

[0004]

However, when a clock that measures real time is installed on a recording medium, the following problem occurs.

[0005] While this timepiece measures the time until the expiration date, there is a possibility that a difference may occur between the time measured by the timepiece and the real time. The time must be able to be modified by an external operation. However, the fact that the measured time of the clock can be manipulated from the outside implies a risk that the clock is illegally operated and the content is reproduced without regard to the expiration date.

In order to avoid such a danger, if a high-precision timepiece with a measurement error close to zero is installed on a recording medium, the cost of the recording medium will increase significantly.

SUMMARY OF THE INVENTION The present invention solves such a conventional problem, and provides a recording medium with an inexpensive configuration capable of preventing unauthorized use of a recorded content beyond its expiration date. It is an object of the present invention to provide a media access control device.

[0008]

Therefore, according to the present invention, in a recording medium for recording content whose expiration date has been set, at least an oscillator, a counter driven by a rectangular wave generated by the oscillator, and an oscillator and a counter are provided. A power supply for supplying driving power and data holding means for holding digitized data are provided.

In a media access control device for accessing the recording medium and outputting contents to the outside, media interface means for exchanging digitized data with the recording medium, and exchanging digitized data with the outside External interface means for performing
Data read control means for controlling reading of digitized data of the content from the recording medium, wherein the data read control means reads digitized data of the content specified from the outside from the recording medium, A check is made to see if the validity period of the content expressed by the value of the counter is present in the data holding means of the recording medium, and if not, the computerized data of the content read from the recording medium is determined. Is output to the outside via the external interface means, and when there is digitized data of the expiration date, the digitized data of the expiration date and the current counter value of the counter in the recording medium are read and compared. ,
If the current counter value does not exceed the expiration date, output the digitized data of the content read from the recording medium to the outside via the external interface unit.If the current counter value has exceeded the expiration date, , So that the digitized data of the content is not output to the outside.

[0010] Therefore, since the expiration date of the content is managed using the counter in the media which cannot be accessed by the user or the application, it has a high fraud prevention effect. Further, since the oscillator for driving this counter does not require a high precision like a clock, the recording medium can be configured at low cost.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) In a first embodiment, a basic configuration of a recording medium and a media access control device of the present invention will be described.

As shown in FIG. 1, the recording medium includes an oscillator 13 and a counter 14 driven by a rectangular wave generated by the oscillator 13.
And a power supply for supplying driving power to the oscillator 13 and the counter 14.
12, a data holding means 15 for holding digitized data, and an external interface means 11 comprising a connector for contacting the media access control device.

The power supply 12 comprises a button battery that cannot be charged, a rechargeable battery or a capacitor that can be charged by external power supply. The counter 14 receives the square wave generated by the oscillator 13 and keeps counting forever. This counter 14 may be an up counter or a down counter.
The counter value of the counter 14 can be read from outside, but it is impossible to set the counter value or operate the counter 14 from outside. In other words, this recording medium 10
Does not have a setting circuit for the counter 14. Therefore, after the recording medium 10 is shipped from the factory, the counter 14 continues counting until the power supply stops.

The data holding means 15 includes digitized data of the content written through the media access control device and digitized data expressing the expiration date of the content by the value of the counter 14 (“digitized data of expiration date”). ) Is held. The digitized data of the content and the digitized data of the expiration date are encrypted and stored in the data holding unit 15. There are several methods for this encryption, the details of which will be described in the third and subsequent embodiments.

The media access control device is provided with only a function of reading content from the recording medium 10. The user access device is, as shown in FIG. 2, media interface means for exchanging digitized data with the recording medium 10. 31, external interface means 33 for exchanging digitized data with the outside, and data reading control means 32 for controlling reading of digitized data of the content held in the data holding means 15 of the recording medium 10 to the outside. ing.

FIG. 3 shows a hardware configuration of the data read control means 32, a program holding unit 53 for holding a program, a CPU 51 for performing data read control processing according to the program, and a work used by the CPU 51 as a work area. A memory 52 is provided.

Further, as shown in FIG. 4, a media access control device used by a maker having a function of writing contents to the recording medium 10 has a structure shown in FIG.
A data writing control means 34 for recording a content with an expiration date set in the data holding means 15 of the recording medium 10 upon receiving a write request with the digitized data of the content and the digitized data of the validity period from the outside. And clock means 35 for measuring real time.

FIG. 5 shows a hardware configuration of the data writing control means 34, a program holding unit 56 for holding a program, a CPU 54 for performing data writing control processing according to the program, and a work used by the CPU 54 as a work area. And a memory 55.

The media access control device 40 shown in FIG.
In each of the data read control means 32 and the data write control means 34, a CPU, a working memory, and a program holding unit may be individually provided, or a single set of a CPU, a working memory, and a program holding unit may be provided. The program holding unit may hold a program that describes both procedures of the data read control process and the data write control process.

The media access control devices 30 and 40 are connected to external devices such as a personal computer (PC), a mobile phone, and a printer via the external interface means 33. Further, the media access control devices 30 and 40 may be incorporated in an external device to constitute a slot for receiving a recording medium.

FIG. 6 shows the CP of the data write control means 34.
U54 shows the procedure of the data writing process performed based on the program. Step 1: When a write request to the recording medium 10 is issued from the external device together with the digitized data of the content and the digitized data of the valid period (T), Step 2: Through the media interface means 31,
The counter value of the counter 14 of the recording medium 10 is checked, and a change amount (Cnt_u) of the counter value while the clock means 35 measures a certain time (t) is measured. The clock means 35 measures real time by a clock signal of an external device, for example.

Step 3: Content validity period (T)
Is calculated by Cnt_u * T / t. Step 4: This is calculated as the current counter value (Cn
t_c) to calculate a counter value (Cnt_l = (Cnt_u * T / t) + Cnt_c) of the counter 14 corresponding to the expiration date.

Step 5: The digitized data of the content received from the outside and the digitized data (Cnt_l) of the expiration date calculated in step 4 are sent to the recording medium 10 via the media interface means 31, and these electronic data are sent. The data is written in the data holding unit 15 in association with the encrypted data.

Note that, as shown in FIG.
By assigning the same file name to the digitized data of the content stored in 15 and the digitized data of the expiration date and changing only the extension, these digitized data can be associated with each other.

FIG. 8 shows the data read control means 32.
3 shows a procedure of a data reading process performed by the CPU 51 based on a program. Step 10: When a content is specified from an external device and the output of the digitized data is requested, Step 11: Digitized data indicating the expiration date of the specified content exists in the data holding unit 15 of the recording medium 10. Find out if you want to. If there is, read it. Step 12: Read the current counter value of the counter 14 of the recording medium 10. Step 13: Check whether the current counter value exceeds the expiration date specified by the value of the counter 14. Check whether or not.

If the expiration date of the content does not exist in step 11, and if the current counter value does not exceed the expiration date in step 13, step 14: read the digitized data of the designated content Output to an external device via the external interface means 33.

If it is determined in step 13 that the current counter value has exceeded the expiration date, step 15: an error signal is output to an external device via the external interface means 33, and the content data is output. Is not performed.

It is to be noted that the error signal is output in such a manner that even when the specified content does not exist in the data holding means 15 of the recording medium 10, the error content can be distinguished from when the content has expired. Constitute.

In step 15, the electronic data of the content whose expiration date has passed is automatically recorded on a recording medium.
The data may be deleted from the ten data holding means 15.

When an external device requests a list of contents stored in the recording medium 10, the data reading control means 32 operates to read the counter of the recording medium 10.
Only contents whose current counter value in 14 does not exceed the expiration date are selected, and the identification IDs or file names of those contents are output to the external device via the external interface means 33.

In this case, the data read control means
32 may be configured to output the content that does not exceed the expiration date by distinguishing between the content that does not exceed the expiration date and the external device to display them in different colors so that the user can distinguish them at a glance.

As described above, by providing the counter on the recording medium and defining the expiration date of the content by the value of the counter, it is possible to set the expiration date of the content with an inexpensive configuration.

(Second Embodiment) As shown in FIG. 9, a recording medium 10 according to a second embodiment includes a unique count value ROM 16 in which a change amount of a counter value of a counter 14 per unit time is recorded. I have.

As the data stored in the unique count value ROM 16, when the recording medium 10 is shipped from the factory, the counter value per unit time of the counter 14 is measured and the value is written.

When writing the digitized data of the content to the recording medium 10,
The data is read from the unique count value ROM 16 of the recording medium 10, and a counter value corresponding to the validity period of the content is calculated using the value. Therefore, the media access control device does not require the clock means 35 of FIG.

The data write processing procedure of the data write control means 34 in this case is the same as that of step 2 in the flowchart of FIG.
Is changed. That is, when a write request to the recording medium 10 is issued from the external device together with the digitized data of the content and the digitized data of the valid period (T) (step 1), step 2: the data writing control unit 34 The data of the amount of change in the counter value of the counter 14 per unit time is read from the unique count value ROM 16 of the recording medium 10 via the media interface means 31.

The amount of change in the counter value per unit time corresponds to (Cnt_u / t). Subsequent processing is the same as in FIG. 6, and using this change amount, a counter value corresponding to the content validity period (T) is calculated (step 3).
The counter value (Cnt_l = (Cnt_u * T / t) + Cnt_c) of the counter 14 corresponding to the expiration date of the content is calculated (step 4). Next, the digitized data of the content received from the outside and the digitized data of the expiration date (Cnt_
l) is sent to the recording medium 10 via the media interface means 31, and these digitized data are associated with each other and written to the data holding means 15.

By providing the unique count value ROM 16 on the recording medium in this way, the prevention of fraud can be enhanced. When the real time is measured using the clock of an external device such as a PC as in the first embodiment,
Although there is a possibility that the unit time is illegally changed by falsifying a timer circuit or the like of the external device, such a possibility is eliminated when the amount of change in the counter value in the unit time is recorded in the unique count value ROM 16.

(Third Embodiment) In the third embodiment,
A method of encrypting digitized data stored in a recording medium will be described.

In the method of the third embodiment, as shown in FIG. 10, the digitized data of the content and the digitized data of the expiration date are encrypted as one data, and this is encrypted by the data holding means 15 of the recording medium. keeping.

As shown in FIG. 11, the data writing control means 34 of the media access control device 40 in this case includes an encryption key ROM 36 for holding an encryption key used for encrypting digitized data.

When a write request to the recording medium is received from the external device, the data writing control means 34 converts the digitized data of the content and the digitized data of the expiration date generated in the procedure of FIG. 6 into one data. The data is synthesized, encrypted with the encryption key obtained from the encryption key ROM 36, and the encrypted digitized data is written to the data holding unit 15 of the recording medium via the media interface unit 31.

On the other hand, as shown in FIGS. 12 and 11, the data read control means 32 of the media access control devices 30 and 40 has a decryption key for holding a decryption key used for decrypting the encrypted electronic data. A key ROM 37 is provided.

When the data reading control means 32 acquires the encrypted digitized data corresponding to the content designated from the external device from the data holding means 15 of the recording medium via the media interface means 31,
Using the decryption key obtained from the decryption key ROM 37, the digitized data is decrypted to separate the digitized data of the content and the digitized data of the expiration date. Next, the expiration date of the content is checked according to the procedure of FIG. 8, and if the expiration date has not expired, the digitized data of the content is output to the external device via the external interface means 33.

It is also possible to obtain an encryption key and a decryption key from an external device without having an encryption key ROM and a decryption key ROM.

In this case, the data write control means 34
When a write request to the recording medium is received from the external device, the digitized data of the content and the digitized data of the expiration date are combined into one data, which is encrypted with an encryption key obtained from the external device, and encrypted. The digitized data is written to the data holding unit 15 of the recording medium via the media interface unit 31.

The data read control means 32 obtains the encrypted digitized data corresponding to the content designated by the external device from the data holding means 15 of the recording medium via the media interface means 31. Using the decryption key obtained from the external device, the digitalized data is decrypted to separate the digitalized data of the content from the digitalized data of the expiration date. Subsequent processing is the same.

When the media access control device determines that the encryption key RO
When the M or decryption key ROM is provided, once the secret of the encryption key and the decryption key is leaked, the subsequent secret cannot be maintained. When the key is obtained, even if the secret of the key is leaked, the key can be changed at any time, so that the secret can be restored and the security is improved.

As described above, by encrypting the digitized data stored in the recording medium, illegal use of the content can be prevented. Further, in this encryption method, since the digitized data of the content and the digitized data of the expiration date are collectively encrypted, the correspondence between the digitized data of the content and the digitized data of the expiration date can be easily obtained. be able to.

(Fourth Embodiment) In the encryption system of the fourth embodiment, as shown in FIG. 13, the digitized data of the content and the digitized data of the expiration date are encrypted with different encryption keys. Is held by the data holding means 15 of the recording medium.

As shown in FIG. 14, the data write control means 34 of the media access control device 40 in this case includes a content encryption key ROM 61 for holding a content encryption key used for encrypting the digitized data of the content, An expiration date encryption key ROM 62 that holds an expiration date encryption key used for encrypting the expiration date electronic data is provided.

When receiving a request to write data to the recording medium, the data write control means 34 converts the digitized data of the content received from the external device into a content encryption key RO.
Encrypts with the encryption key obtained from M61, and converts the expiration date electronic data related to this content into an expiration date encryption key ROM.
The digitized data encrypted with the encryption key obtained from 62 is written to the data holding unit 18 of the recording medium via the media interface unit 31.

On the other hand, the data read control means 32 of the media access control devices 30 and 40 holds a content decryption key used for decrypting the digitized data of the encrypted content as shown in FIGS. A content decryption key ROM 63 and an expiration date decryption key ROM 64 that stores an expiration date decryption key used for decrypting the encrypted expiration date digitized data.

When the data reading control means 32 obtains the encrypted electronic data of the expiration date corresponding to the content designated from the external device from the data holding means 15 of the recording medium via the media interface means, The expiration date is decrypted using the expiration date decryption key obtained from the expiration date decryption key ROM 64, and the expiration date of the content is checked in the procedure shown in FIG. If the expiration date has not expired, digitized data of the encrypted content stored in the data storage unit 15 of the recording medium is obtained via the media interface unit 31 and the content decryption key ROM
After decrypting using the content decryption key obtained from 63,
Output to external device.

Also, in this case, the media access control device is configured to execute at least one of the content encryption key, the expiration date encryption key, the content decryption key, or the expiration date decryption key.
One of them can be obtained not from the ROM but from an external device to encrypt or decrypt the digitized data.

As described above, in this encryption method, the expiration date can be checked only by decrypting the encrypted electronic data of the expiration date. Can be quickly determined.

(Fifth Embodiment) In the encryption method of the fifth embodiment, as shown in FIG. 16, the digitized data of the encrypted content, its decryption key, and the As one data, which is encrypted with a key different from the encryption key of the digitized data of the content.

As shown in FIG. 17, the data write control means 34 of the media access control device 40 in this case includes a content encryption key ROM 61 for holding a content encryption key used for encrypting digitized data of the content, A content decryption key ROM 63 that holds a content decryption key used for decrypting encrypted content, digitized data of the encrypted content, digitized data of the expiration date, and a content decryption key are combined into one. A combined data encryption key ROM 65 for holding a combined data encryption key used for encrypting the combined data.

When the data writing control means 34 receives the request for writing to the recording medium, the data writing control means 34 encrypts the digitized data of the content received from the external device with the encryption key obtained from the content encryption key ROM 61 and performs the encryption. The digitized data of the content, the digitized data of the expiration date, and the content decryption key obtained from the content decryption key ROM 63 are combined into one data, and the data is combined with the encryption key obtained from the combined data encryption key ROM 65. The data is encrypted and written to the data holding unit 15 of the recording medium via the media interface unit 31.

On the other hand, as shown in FIG. 18 and FIG. 17, the data read control means 32 of the media access control devices 30 and 40 converts the digitized data of the encrypted content, the digitized data of the expiration date, A decryption key ROM 66 for storing a decryption key used for decrypting encrypted data by converting a decrypted content into a piece of composite data with a decryption key for decrypting the content is provided.

The data read control means 32 obtains the encrypted composite data corresponding to the content designated from the external device from the data holding means 15 of the recording medium, and obtains the decryption key obtained from the decryption key ROM 66. And decrypt it. Then, using the electronic data of the expiration date obtained by this decryption, the expiration date of the content is checked in the procedure of FIG. If the expiration date has not expired, the encrypted content digitized data is decrypted using the content decryption key obtained by decryption, and output to an external device.

The data writing control means 34 may receive at least one of a content encryption key, a content decryption key, and a composite data encryption key from an external device. Further, the data read control means 32 may receive the decryption key from an external device.

Further, here, the combined data is generated by combining the digitized data of the encrypted content, the digitized data of the expiration date, and the content decryption key into one, and this is encrypted. Instead of including the digitized data of the content, the composite data may be generated by using the digitized data of the expiration date and the content decryption key, and this may be encrypted.

In this encryption method, it is sufficient to prepare one decryption key when reading data, so that the configuration of a read-only media access control device can be simplified. (Sixth Embodiment) In the encryption method of the sixth embodiment,
As shown in FIG. 19, data holding means of the recording medium 10
The electronic data is stored separately in the general data holding unit 17 and the secret data holding unit 18 in FIG.

The general data holding unit 17 reads / writes data in a generally disclosed procedure, but the data reading / writing procedure to the secret data holding unit 18 is not disclosed to the public. Therefore, only the media access control device that knows the secret procedure is the secret data holding unit.
Data can be read / written from / to 18.

In the encryption system of this embodiment, as shown in FIG. 20, the digitized data of the encrypted content is stored in the general data holding unit 17 of the data holding unit 15, and the secret data is stored in the secret data holding unit 18. The decryption key and the electronic data of the expiration date are stored.

In this case, as shown in FIG. 21, the data write control means 34 of the media access control device 40 includes an encryption key ROM 36 for storing an encryption key used for encrypting the digitized data, and an encryption key ROM 36 for storing the encryption key. And a decryption key ROM 37 for storing a decryption key for decrypting the digitized data encrypted by the encryption key.

The data writing control means 34 converts the digitized data of the content received from the external device into an encryption key ROM.
The data is encrypted with the encryption key obtained from 36, written into the general data holding unit 17 of the data holding means 15 of the recording medium 10 by a publicly available writing procedure, and the electronic key of the decryption key obtained from the decryption key ROM 37 is written. The encrypted data and the digitized data of the expiration date are written to the secret data holding unit 18 of the data holding means 15 by a secret writing procedure that is not made public.

On the other hand, the data read control means 32
As shown in FIG. 2 and FIG. 21, there is no need to prepare a decryption key. The data read control unit 32 acquires the digitized data of the encrypted content stored in the general data storage unit 17 of the data storage unit 15 of the recording medium 10 by a publicly disclosed read procedure, and Means 15
The decryption key of the content and the electronic data of the expiration date stored in the secret data holding unit 18 are obtained by a secret reading procedure that is not generally disclosed.

Using the digitized data of the expiration date, the expiration date of the content is checked according to the procedure shown in FIG. 8, and if the expiration date has not expired, the decryption key read from the secret data holding unit 18 is checked. Is used to decrypt the digitized data of the encrypted content and output it to an external device.

The data writing control means 34 may receive at least one of a content encryption key and a content decryption key from an external device.

In this encryption method, it is not necessary to prepare a decryption key when reading data from a recording medium. Therefore, the configuration of the read-only media access control device can be simplified.

In this case, the electronic data of the expiration date is written in the secret data holding unit 18 without being encrypted, but it may be written in an encrypted form just in case.

The counter of the recording medium can be used as an up counter whose value increases or a down counter whose value decreases.

[0075]

As is apparent from the above description, the recording medium of the present invention manages the expiration date of the content by using the counter in the medium which cannot be accessed by the user or the application, and therefore has a high fraud prevention effect. have. Also, the oscillator that drives this counter does not require a high precision like a clock. Therefore, the recording medium can be configured at low cost.

Further, the media access control device of the present invention can record a content having an expiration date on this recording medium, and can read the content while keeping the expiration date.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a recording medium according to a first embodiment,

FIG. 2 is a configuration diagram of a read-only media access control device according to the first embodiment;

FIG. 3 is a hardware configuration diagram of a data read control unit according to the first embodiment;

FIG. 4 is a configuration diagram of a read / write medium access control device according to the first embodiment;

FIG. 5 is a hardware configuration diagram of a data write control unit according to the first embodiment;

FIG. 6 is a flowchart showing a processing procedure of a data write control unit according to the first embodiment;

FIG. 7 is a diagram showing how data is held by a data holding unit according to the first embodiment;

FIG. 8 is a flowchart showing a processing procedure of a data read control unit according to the first embodiment;

FIG. 9 is a configuration diagram of a recording medium according to a second embodiment;

FIG. 10 is a diagram showing how data is held by a data holding unit according to the third embodiment;

FIG. 11 is a configuration diagram of a read / write medium access control device according to a third embodiment;

FIG. 12 is a configuration diagram of a read-only media access control device according to a third embodiment;

FIG. 13 is a diagram illustrating how data is held by a data holding unit according to a fourth embodiment;

FIG. 14 is a configuration diagram of a read / write medium access control device according to a fourth embodiment;

FIG. 15 is a configuration diagram of a read-only media access control device according to a fourth embodiment;

FIG. 16 is a diagram illustrating how data is held by a data holding unit according to a fifth embodiment;

FIG. 17 is a configuration diagram of a read / write medium access control device according to a fifth embodiment;

FIG. 18 is a configuration diagram of a read-only media access control device according to a fifth embodiment;

FIG. 19 is a configuration diagram of a recording medium according to a sixth embodiment;

FIG. 20 is a diagram showing how data is held by a data holding unit according to the sixth embodiment;

FIG. 21 is a configuration diagram of a read / write medium access control device according to a sixth embodiment;

FIG. 22 is a configuration diagram of a read-only media access control device according to a sixth embodiment.

[Explanation of symbols]

 10 Recording media 11 External interface unit 12 Power supply 13 Oscillator 14 Counter 15 Data holding unit 16 Unique count value ROM 17 General data holding unit 18 Secret data holding unit 30 Read-only media access control unit 31 Media interface unit 32 Data read control unit 33 External Interface means 34 Data writing control means 35 Clock means 36 Encryption key ROM 37 Decryption key ROM 40 Read / write media access control device 51, 54 CPU 52, 55 Work memory 53, 56 Program holding unit 61 Content encryption key ROM 62 Expiration date encryption key ROM 63 Content decryption key ROM 64 Expiration date decryption key ROM 65 Synthetic data encryption key ROM 66 Decryption key ROM

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) H04L 9/08 H04L 9/00 601B F-term (Reference) 5B017 AA03 BA07 BB10 CA15 CA16 5B035 AA13 BB09 BC00 CA11 CA12 CA38 5B058 CA27 KA02 KA04 KA31 KA35 YA12 5B065 BA09 CA12 CA40 CC08 PA04 PA11 PA16 5J104 NA02 PA14

Claims (34)

[Claims] 1. A recording medium for recording content whose expiration date has been set, comprising: at least an oscillator; a counter driven by a rectangular wave generated by the oscillator; a power supply for supplying drive power to the oscillator and the counter; A recording medium, comprising: data holding means for holding data. 2. The apparatus according to claim 1, wherein the counter value of the counter can be read from the outside, but the counter value of the counter cannot be set or the counter cannot be operated from the outside. Recording media. 3. The recording medium according to claim 1, wherein the power supply is a non-rechargeable battery. 4. The recording medium according to claim 1, wherein the power supply is a battery or a capacitor that can be charged by external power supply. 5. The method according to claim 1, wherein the data holding unit holds the digitized data of the content and the digitized data of the expiration date expressing the expiration date of the content by the value of the counter. 4. The recording medium according to any one of 4. 6. The recording medium according to claim 5, wherein the digitized data of the content and the digitized data of the expiration date are put together and encrypted. 7. The recording medium according to claim 5, wherein the digitized data of the content and the digitized data of the expiration date are respectively encrypted with different encryption keys. 8. The computerized data of the content is encrypted, and its decryption key and the computerized data of the expiration date are combined into one, which is different from the encryption key of the computerized data of the content. 6. The recording medium according to claim 5, wherein the recording medium is encrypted with a key. 9. The data holding unit comprises: a general data holding unit for reading and writing data in a generally disclosed procedure; and a secret data holding unit for reading and writing data in a procedure not to be disclosed to the public. Wherein the encrypted electronic data of the content is held in the general data holding unit, and the decryption key of the content and the electronic data of the expiration date are held in the secret data holding unit. The recording medium according to claim 5, wherein 10. The recording medium according to claim 1, further comprising a unique count value ROM that holds a value that the counter driven by the oscillator counts for a predetermined time. 11. A media access control device for accessing a recording medium for recording content whose expiration date has been set and outputting the content to the outside, wherein the recording medium comprises at least an oscillator and a rectangular wave generated by the oscillator. A counter to be driven, a power supply for supplying drive power to the oscillator and the counter, and a data holding unit for holding digitized data, wherein the data holding unit includes digitized data of a content including a program and data; A media interface unit for exchanging the digitized data with the recording medium, wherein the media access control device holds the expiration date of the content expressed by the value of the counter; And an external interface for exchanging digitized data with the outside And data reading control means for controlling reading of digitized data of the content from the recording medium, wherein the data reading control means reads the digitized data of the content specified from the outside from the recording medium. First, it is checked whether or not electronic data of the expiration date expressing the expiration date of the content by the value of the counter exists in the data holding unit of the recording medium. Outputting the digitized data to the outside via the external interface means, and reading out the expiration date digitized data and the current counter value of the counter in the recording medium when the expiration date exists. Compare
If the current counter value does not exceed the expiration date, output the digitized data of the content read from the recording medium to the outside via the external interface means, and if the current counter value has exceeded the expiration date, And a media access control device that does not output digitized data of the content to the outside. 12. The external interface unit has an error signal line, and the data read control unit detects that the current counter value has exceeded the expiration date, and when the electronic counter of the designated content is detected. When detecting that the digitized data does not exist in the data holding unit of the recording medium, digitized data representing different errors is generated and output to the outside via the error signal line. 12. The media access control device according to item 11. 13. The data reading control means according to claim 1, wherein when a list of contents in said recording medium is designated from outside, a content of a counter in said recording medium whose current counter value does not exceed said expiration date is set. 12. The media access control according to claim 11, wherein only the selected content is obtained, an identification ID or a file name in the recording medium of the digitized data of the content is obtained, and output to the outside via the external interface means. apparatus. 14. The data reading control means according to claim 1, wherein when a list of contents in said recording medium is designated from outside, a content of a counter in said recording medium whose current counter value does not exceed said expiration date is specified. And the content exceeding the expiration date is obtained by acquiring the identification ID or the file name of the digitized data of the content in the recording medium, via the external interface means. 12. The media access control device according to claim 11, wherein the identification ID or the file name is output to the outside so that the identification ID or the file name of the content whose expiration date is exceeded can be distinguished. 15. The data reading control means, when detecting a content whose current counter value of the counter in the recording medium exceeds the expiration date, digitizes the content and the expiration date of the content. 15. The media access control device according to claim 11, wherein data and data are deleted from the data holding unit of a recording medium. 16. A recording apparatus comprising: clock means for acquiring the current actual time as digitized data; and data writing control means for recording content having an expiration date set on the recording medium. A write request to the recording medium with the digitized data of the content and the digitized data of the valid period is received, and the count value of the counter in the recording medium is acquired while the clock means detects a certain time. Calculating the count value of the counter corresponding to the validity period of the content, adding the calculated count value to the current counter value to create electronic data of the expiration date, and receiving the content received from the outside. By associating the digitized data with the digitized data of the expiration date, via the media interface means. 16. The medium access control device according to claim 11, wherein the data is written in a data holding unit of a recording medium. 17. A data writing control means for recording content with an expiration date set on the recording medium, wherein the data writing control means externally attaches digitized data of the content and digitized data of the validity period. Received a write request to the recording medium, and obtains, via the media interface means, a value of a unique count value ROM that holds the value counted by the counter in a certain period of time provided in the recording medium, and obtains a value of the content. Calculate the count value of the counter corresponding to the validity period, create the digitized data of the expiration date by adding the calculated count value to the current counter value, and digitize the data of the content received from outside with the Linking the media interface means with the electronic data of the expiration date; And writing the data to a data holding unit of the recording medium via the storage medium.
6. The media access control device according to any one of 5. 18. A storage medium, comprising: a decryption key ROM for storing a decryption key used for decrypting encrypted electronic data; wherein the data read control means corresponds to an externally designated content. Acquiring the encrypted digitized data held by the data holding means via the media interface means, and decrypting the digitized data using a decryption key obtained from the decryption key ROM; The media access control device according to claim 11, wherein the computerized data of the content in the computerized data is output to the outside via the external interface unit. 19. The data read control unit obtains, via the media interface unit, encrypted electronic data corresponding to content specified from the outside and stored in the data storage unit of the recording medium. And decrypting the digitized data using a decryption key obtained from outside via the external interface means,
The media access control device according to claim 11, wherein the computerized data of the content in the computerized data is output to the outside via the external interface unit. 20. An encryption key ROM for storing an encryption key used for encrypting digitized data, wherein the data writing control means digitizes the content when receiving a write request to the recording medium. The data and the expiration date electronic data are combined into one data and encrypted with an encryption key obtained from the encryption key ROM, and the encrypted electronic data is recorded via the media interface means. 18. The medium access control device according to claim 16, wherein the data is written in a data holding unit of the medium. 21. The data writing control means, when receiving a write request to the recording medium, combines the digitized data of the content and the digitized data of the expiration date into one data, and Encrypted with an encryption key obtained from outside via the interface means,
18. The media access control device according to claim 16, wherein the encrypted digitized data is written to data holding means of the recording medium via the media interface means. 22. A content decryption key ROM for holding a content decryption key used for decrypting the encrypted electronic data of the content, and used for decrypting the encrypted electronic data of the expiration date. An expiration date decryption key ROM for holding an expiration date decryption key, wherein the data read control unit corresponds to an externally designated content and is encrypted and held in the data storage unit of the recording medium. The electronic data of the validity period is obtained through the media interface unit, and is decrypted using the validity period decryption key obtained from the validity period decryption key ROM, and is stored in the data storage unit of the recording medium. The encrypted electronic content data of the content is obtained through the media interface means, and the content is decrypted. 2. The decryption using a content decryption key obtained from an encryption key ROM.
2. The media access control device according to 1. 23. The data reading control means, wherein the validity term decryption key for decrypting the encrypted validity term electronic data or the encrypted content electronic data is decrypted. At least one of the content decryption keys to be obtained is obtained from the outside via the external interface means, and the encrypted electronic data of the expiration date corresponding to the content specified from the outside is stored in the recording medium. Means for decrypting the content using the expiration date decryption key, and obtaining the encrypted electronic data of the content from the data holding means of the recording medium and decrypting the content using the content decryption key. The media access control device according to claim 11, wherein: 24. A content encryption key ROM for holding a content encryption key used for encrypting the digitized data of the content, and an expiration date encryption key used for encrypting the digitized data of the expiration date. An expiration date encryption key ROM, wherein the data writing control means, when receiving a write request to the recording medium, encrypts digitized data of the content received from outside from the content encryption key ROM. Encrypted with the encryption key,
The electronic data of the expiration date relating to the content is encrypted with an encryption key obtained from the expiration date encryption key ROM, and the encrypted electronic data is transferred to a data holding unit of the recording medium via a media interface unit. 18. The media access control device according to claim 16, wherein writing is performed. 25. The data writing control means includes a content encryption key for encrypting digitized data of the content or at least one of an expiration date encryption key for encrypting the expiration date digitized data. When externally obtained via the external interface means and a write request to the recording medium is received, digitized data of the content received from the outside is encrypted with a content encryption key, and the expiration date for the content is obtained. 18. The method according to claim 16, wherein the digitized data is encrypted with an expiration date encryption key, and the encrypted digitized data is written to a data holding unit of the recording medium.
2. The media access control device according to claim 1. 26. A decryption key used for decrypting encrypted data by converting the electronic data of the expiration date and the digitalized data of a decryption key for decrypting the encrypted content into one composite data. A decryption key ROM for storing the data, and the data readout control means transmits the encrypted synthetic data stored in the data storage means of the recording medium corresponding to the content designated from the outside to the media interface means. And decrypting the content using a decryption key obtained from the decryption key ROM, and separating the content into a decryption key for decrypting the content and digitized data of the expiration date. Acquiring, via the media interface means, digitized data of the specified content, which is stored in the 12. The media access control device according to claim 11, wherein the decryption is performed using a decryption key for decrypting. 27. The data reading control means according to claim 1, wherein said data read control means is an encrypted composite data of electronic data of an expiration date corresponding to the content designated from outside and a content decryption key for decrypting said encrypted content. From the data holding unit of the recording medium, and decrypted using a decryption key obtained from the outside via the external interface unit, and converts the synthesized data into a content decryption key and electronic data of an expiration date. 12. The media access control according to claim 11, wherein the encrypted digitized data of the content obtained from the data holding unit of the recording medium is separated and decrypted using the content decryption key. apparatus. 28. A content encryption key ROM holding a content encryption key used for encrypting digitized data of a content, and a content decryption key holding a content decryption key used for decrypting the encrypted content RO
M and a combined data encryption key ROM for holding a combined data encryption key used for encrypting the combined data obtained by combining the expiration date of the digitized data and the content decryption key into one,
The data writing control means, when receiving a write request to the recording medium, encrypts the digitized data of the content received from the outside with an encryption key obtained from the content encryption key ROM, and The digitized data and the decryption key obtained from the content decryption key ROM are combined into one data and encrypted with the encryption key obtained from the composite data encryption key ROM. 18. The media access control device according to claim 16, wherein writing is performed. 29. The data writing control means includes: a content encryption key for encrypting digitized data of a content; a content decryption key used for decrypting the encrypted content; When obtaining at least one of the combined data encryption keys used for encrypting the combined data obtained by combining the decryption key with one from the outside via the external interface means, and receiving a write request to the recording medium, Encrypting the digitized data of the content received from the outside with a content encryption key, synthesizing the digitized data of the expiration date and the content decryption key into one data, and encrypting the data with a composite data encryption key; 17. The method according to claim 16, wherein the encrypted digitized data is written to a data holding unit of the recording medium. 8. The media access control device according to 7. 30. The data read control unit, when outputting a content designated from the outside to the outside, stores the encrypted content stored in a general data holding unit of the data holding unit of the recording medium via the media interface unit. Obtain the digitized data of the converted content by a publicly available readout procedure, and obtain the decryption key of the content and the digitized data of the expiration date stored in the secret data holding unit of the data holding unit. Obtained by a non-disclosed readout procedure that is not generally disclosed, and decrypts the encrypted digitized data of the content obtained from the general data holding unit with a decryption key obtained from the secret data holding unit. The digitalized data is output to the outside via an external interface means. Media access control device. 31. An encryption key ROM for holding an encryption key used for encrypting digitized data, and a decryption key for holding a decryption key for decrypting digitized data encrypted with the encryption key. And a data write control unit, when receiving a write request to the recording medium, encrypts the digitized data of the content received from the outside with an encryption key obtained from the encryption key ROM. The storage medium of the storage medium is written in a general data holding unit of the data holding unit by a writing procedure that is publicly disclosed. 18. The media according to claim 16 or 17, wherein the data is written into the secret data holding unit of the data holding means by a non-public writing procedure that is not generally made public. Access control device. 32. The data writing control means stores at least one of an encryption key used for encrypting digitized data or a decryption key for decrypting digitized data encrypted with the encryption key. When externally obtained via an external interface means and a write request to the recording medium is received, digitized data of the content received from the outside is encrypted with the encryption key, and the data holding means of the recording medium is stored. The storage medium writes the digitized data of the decryption key and the digitized data of the expiration date, which are written in a general data holding unit by a generally disclosed writing procedure, and which decrypts the digitized data encrypted with the encryption key. 17. The method according to claim 16, wherein the data is written into the secret data holding unit of the data holding means by a secret writing procedure that is not generally made public. 8. The media access control device according to 7. 33. A program for performing a data read control process of a media access control device for accessing a recording medium for recording a content whose expiration date has been set and outputting the content to the outside, the program comprising: A step of checking whether or not the expiration date digitized data expressing the expiration date of the content by the value of the counter exists in the recording medium; and a step of, if the expiration date digitization data does not exist, reading the content read out from the recording medium. Outputting the digitized data to the outside, and, when there is the digitized data of the expiration date, reading and comparing the digitized data of the expiration date and the current counter value of the counter in the recording medium. If the current counter value does not exceed the expiration date, read from the recording medium. Outputs electronic data of the content to the outside, if it exceeds the expiration date, a program for executing the procedures to avoid outputting digitized data of the content to the outside. 34. A program for performing a data writing control process of a media access control device for accessing a recording medium for recording content whose expiration date has been set and writing the content to the recording medium, comprising: Receiving a write request to the recording medium with the digitized data and the digitized data of its validity period; acquiring a count value per unit time of a counter in the recording medium; and Calculating the count value of the counter corresponding to the validity period of the content based on the per-count value; and Procedures for creating and electronic data of the content received from outside And writing the data to the recording medium in association with the data of the expiration date.