JP2002204229A - Device and method for ciphering, device and method for deciphering cipher, and ciphering system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a ciphered object from easily being deciphered by a 3rd party. SOLUTION: Each time respective raw materials are inputted, UMID(unique material identifier) data D11 specifying the respective raw materials are generated and the UMID data D11 corresponding to the respective raw materials are converted under mathematical conditions of a cipher key D10 to generate raw material specifying cipher keys D13 intrinsic to the respective raw materials; and mutually different data arrangement patterns (shuffling table data D14 and interleaving table data D15) corresponding to the raw materials are ciphered respectively with the raw material specifying cipher keys D13 to generate ciphered data D16 and D17 corresponding to the raw materials, thereby generating the raw material specifying cipher keys D13 which disables a 3rd party to decipher the data without knowing all of the algorithm of the cipher key D10, the conversion patterns for conversion to the raw material specifying cipher keys D13 based upon the UMID data D11 specified by the raw materials, and the UMID data D11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encryption device, an encryption method, an encryption / decryption device, an encryption / decryption method, and an encryption system, for example, an encryption system constructed by a digital video camera recorder and a digital video tape recorder. It is suitable for application to a system.

[0002]

2. Description of the Related Art Conventionally, a digital video tape recorder (hereinafter, referred to as a video tape recorder) is provided on a magnetic tape of a video cassette by a digital video camera recorder (hereinafter, referred to as a video camera) by operation of a photographer. By reproducing the recorded image data, a reproduced video is displayed on an external monitor.

However, in a video tape recorder, even when a playback operation is performed by an unintended third party by a photographer, the playback image is displayed on an external monitor. Had been seen.

[0004] One method for solving such a problem is to perform a video data recording process on a magnetic tape of a video cassette after performing an encryption process based on a predetermined encryption algorithm on image data obtained by imaging. It is conceivable to construct an encryption system with a camera and a video tape recorder that restores the original image data by performing a decryption process based on the same encryption algorithm as that of the video camera when playing the video cassette. Can be

[0005]

In such an encryption system, since the video camera always performs the encryption process based on the same encryption algorithm,
When the encryption algorithm is decrypted by an unintended third party, there is a problem that all the reproduced images of the video cassette captured by the video camera are visually recognized via the video tape recorder.

The present invention has been made in view of the above points, and is an encryption apparatus, an encryption method, an encryption / decryption apparatus, and an encryption apparatus capable of preventing a third party from easily decrypting an object to be encrypted. It proposes a decryption method and an encryption system.

[0007]

According to the present invention, in order to solve the above-mentioned problems, unique information for specifying each material is generated each time each material is input, and unique information corresponding to each material is generated. The information is converted in accordance with a predetermined method to generate a unique encryption key for each material, and each material or predetermined information corresponding to each material is encrypted with the encryption key, so that it is difficult to guess by analogy. Unless all the information is known, a third party can generate an encryption key for each unique material that cannot be decrypted at all, thus preventing the third party from easily decrypting the encryption target I can do it.

[0008] Further, as predetermined information corresponding to each material, a data rearrangement pattern for rearranging each material in a predetermined data amount unit each time each material is input is encrypted. Thus, the data can be encrypted with a much smaller amount of data than when the material itself is encrypted.

In order to solve this problem, according to the present invention, each time a material is input, unique information generated for identifying the material is generated, and unique information is generated for each material based on the unique information. Each material or predetermined information corresponding to each material is encrypted with an encryption key, and encrypted data generated is obtained from an encryption device, and unique information corresponding to each material is converted according to a predetermined method. By generating a decryption key for decrypting the encrypted data respectively, decrypting the encrypted data with the decryption key and restoring each material or predetermined information corresponding to each material, the analogy is made. A decryption key can be generated by acquiring difficult unique information and an encryption key for each unique material that cannot be decrypted by a third party because it is generated based on the unique information. In may reliably and accurately recover the predetermined information corresponding to each element or each material.

In order to further solve the above-mentioned problem, in the present invention, each time a material is input, unique information for specifying the material is generated, and the unique information corresponding to each material is converted into a predetermined format. Generates a unique encryption key for each material, encrypts each material or predetermined information corresponding to each material with the encryption key to generate encrypted data, and generates a unique encrypted key. An encryption device for transmitting information, and decryption for receiving the encrypted data and the unique information, converting the unique information corresponding to each material according to a predetermined method, and decrypting the encrypted data. By generating a key and decrypting the encrypted data with the decryption key, respectively, and constructing an encryption / decryption device for restoring each material or predetermined information corresponding to each material, the encryption device Unless all of the unique information that is difficult to guess is unknown, it is possible to generate an encryption key for each unique material that cannot be decrypted at all by a third party, so that the encryption target can be easily decrypted by the third party. The encryption / decryption device uses unique information that is difficult to guess through transmission means and unique material that cannot be decrypted by a third party because it is generated based on the unique information. Since a decryption key can be generated by receiving an encryption key for each material, each material or predetermined information corresponding to each material can be reliably and accurately restored.

In order to further solve the above-mentioned problem, in the present invention, each time each material is input, unique information for specifying each material is generated, and the unique information corresponding to each material is converted into a predetermined format. Generates a unique encryption key for each material, encrypts each material or predetermined information corresponding to each material with the encryption key to generate encrypted data, and generates a unique encrypted key. An encryption device that stores information in a predetermined storage medium, reads the encrypted data and unique information from the storage medium, converts the unique information corresponding to each material according to a predetermined method, and converts the encrypted data. An encryption / decryption device that generates a decryption key for each decryption, decrypts the encrypted data with the decryption key, and restores each material or predetermined information corresponding to each material. By constructing the encryption device, the encryption device can generate an encryption key for each unique material that cannot be decrypted by a third party unless all of the unique information that is difficult to guess is known. The decryption device can prevent the decryption target from being easily decrypted by the user, and the encryption / decryption device uses the unique information read from the storage means that is difficult to guess and the third party because the unique information is generated based on the unique information. It is possible to receive the encryption key for each unique material that cannot be decrypted at all and generate the decryption key, so that it is possible to reliably and accurately restore each material or each piece of predetermined information corresponding to each material. obtain.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

(1) Network-Compatible Encryption System In FIG. 1, reference numeral 1 denotes a network-compatible encryption system as a whole according to the present invention, which includes a digital video camera recorder (hereinafter referred to as a video camera) 2 and
A digital video tape recorder (hereinafter referred to as a video tape recorder) 3 is connected to the Internet 4 via a personal computer (not shown).
, So that various kinds of information can be exchanged between the digital video camera 2 and the video tape recorder 3.

This network-compatible encryption system 1
In, a video cassette 5 in which image data, which is a material obtained by imaging with a video camera 2, is subjected to predetermined processing and recorded is loaded into a video tape recorder 3 and played.

(2) Encryption Processing Procedure in Video Camera An encryption processing procedure in the present embodiment will be described using the video camera 2 having a circuit configuration as shown in FIG.

The video camera 2 has a CPU (Central P
(Processing Unit) 10, IEEE (Institute of Electrical and Electronical System) for exchanging various information with other devices (personal computer in this embodiment)
cs Engineers) 1394 Interface (I / F) 1
1, a memory 12, an input unit 13 provided with various operation buttons (not shown), and a display unit 14 composed of a liquid crystal display
And an encryption unit 26 are connected to each other via a data bus BUS. The CPU 10 performs predetermined processing in accordance with various programs read from the memory 12 to control the video camera 2 as a whole, and 27, the magnetic tape 2 of the video cassette 5 (FIG. 1)
0 is recorded.

In practice, in FIG. 3, the CPU 10 proceeds from the start step of the encryption processing procedure according to the routine RT1 to step SP1.

In step SP1, the CPU 10 first sends the video data from the video tape recorder 3 to the Internet 4.
An encryption key D10 according to RSA, which is an asymmetric encryption method, transmitted via (FIG. 1) is acquired in advance via the IEEE1394 interface 11, stored in the memory 12, and proceeds to the next step SP2.

In step SP2, the CPU 10 determines whether or not the recording button of the input unit 13 has been pressed by the photographer. If a negative result is obtained here, the CPU 1
0 waits until the record button is pressed. On the other hand, if a positive result is obtained, the CPU 10 moves to the next step SP3.

In step SP3, the CPU 10
A UMID (Uniqud) for specifying materials such as image data and audio data based on various information stored in the memory 12 and a system clock by the MID generation unit 21.
e Material IDentifier), and a part of the UMID is extracted as UMID data D11.
The information is transmitted to the MID encryption unit 22 and the material identification encryption key generation unit 23, and proceeds to the next step SP4.

Here, the data structure of the UMID will be described. In FIG. 4, the UMID is composed of 64 [bytes] of the basic UMID and the extended UMID.
Is a universal label of 12 [bytes] indicating the UMID, etc., a data length of 1 [byte] indicating the data length, an instrument number of 3 [bytes] indicating the number of dubbing times, and the video camera 2 or its video camera. It consists of a total of 32 [bytes] including a 16 [byte] material number generated as unique information by multiplying the serial number unique to the chip in 2 by a random number.

The extended UMID represents a date and time based on the system clock in the video camera 2.
In the case of a video camera having a GPS (Global Positioning System) function, the date and time of the location, 12 [byte] position information indicating the location of the video camera, and 4 [byte] indicating the country
It consists of a total of 32 [bytes] including the country code, 4 [byte] organization code representing the organization, and 4 [byte] user name representing the user.

In the case of this embodiment, the CPU 10 extracts the basic UMID including the material number, which is unique information, from the UMID as the UMID data D11, and can specify the material by the material number. It has been made like that.

As described above, the CPU 10 generates new UMID data D11 for specifying a material every time the recording button is pressed by the photographer.

In step SP4, the CPU 10 sends the encryption key D10 stored in the memory 12 to the UMID encryption unit 22 and the material-specific encryption key generation unit 23,
Move to the next step SP5.

In step SP5, the CPU 10 converts the UMID data D11 for specifying the material in accordance with the mathematical condition based on the encryption key D10 by the material specifying encryption key generating unit 23, thereby obtaining the encryption unique to the material. A material-specific encryption key D13, which is an encryption key, is generated.

The CPU 10 also includes a UMID encryption unit 22
The UMID data D11 necessary for decrypting the material identification encryption key D13 in the video tape recorder 3 is subjected to an encryption process with the encryption key D10 transmitted from the video tape recorder 3, and the encrypted UMID data By generating D12, it is possible to prevent decryption by a third party when transmitting to the video tape recorder 3 via the Internet 4.

Then, the CPU 10 sends the material-specific encryption key D
13 to the table encryption unit 25 and the cipher U
After temporarily storing the MID data D12 in the memory 12, the process proceeds to the next step SP6.

In step SP6, the CPU 10 displays, for example, a pattern determination screen 14A as shown in FIG. 5 on the display unit 14, and the data rearrangement pattern when the shuffling unit 16 and the interleave unit 18 rearrange the data sequence. To the photographer to make the decision.

Then, the CPU 10 sets the pattern determination screen 1
First pattern (shuffling) item 14 via 4A
When a desired pattern number is selected and operated from the input unit 13 by the photographer from the B and second pattern (interleave) items 14C, a shuffling table which is a data rearrangement pattern corresponding to each of the selected pattern numbers. The data D14 and the interleave table data D15 are converted into, for example, 16 Modull
o It is arbitrarily generated according to the function of 4, and the next step SP7
Move on to

Incidentally, the CPU 10 allows the photographer to select a data rearrangement pattern each time the recording button is pressed, similarly to the UMID data D11 newly generated each time the recording button is pressed. New shuffling table data D14 and interleave table data D15 are generated.

In step SP7, the CPU 10 stores the shuffling table data D14 in the shuffling section 16.
And the interleaving table data D15 is sent to the interleaving section 18 to set a data rearrangement pattern for the shuffling section 16 and the interleaving section 18, respectively, and to set the shuffling table data D14 and the interleaving table data D15. From the table generation unit 24 to the table encryption unit 25
And proceeds to the next step SP8.

In step SP8, the CPU 10 causes the table encryption unit 25 to execute the material identification encryption key generation unit 23 on the shuffling table data D14 and the interleave table data D15 set by the shuffling unit 16 and the interleave unit 18, respectively. Material-specific encryption key D, which is a material-specific encryption key supplied from
By performing the encryption processing at 13, the Internet 4
The encrypted data D16 and D17 are generated so as not to be decrypted by a third party when transmitted to the video tape recorder 3 via (FIG. 1). Move to step SP9.

In step SP9, the CPU 10 performs the MPM processing on the image data, which is the material obtained by imaging when the recording button is pressed in step SP2.
An elementary stream D1 that has been subjected to compression coding processing of the EG2 (Moving Picture Experts Group-layer 2) method
Through the input terminal 15 to the shuffling unit 16 of the recording unit 27.
To enter.

The shuffling unit 16 performs the above-described step S
According to the data rearrangement pattern of the shuffling table data D14 set in P7, shuffling for rearranging each macroblock for one frame of the elementary stream D1 is performed.

The main purpose of this shuffling is as follows.
By dispersing the recording positions of the macroblocks on the magnetic tape, it is possible to make the reproduced video as easy as possible when an error that cannot be corrected occurs at the time of variable speed reproduction that reproduces at a tape speed different from the recording time. is there.

Incidentally, a macroblock is an MPEG2
In the data structure of (4), four Y (luminance) signal blocks of 16 lines × 16 pixels and a C _r (R (red) component of 16 lines × 16 pixels corresponding to the four Y signal blocks and Y
Refers to the color difference component) signals and C _b (B (blue) color difference components between the component and the Y component) signal unit formed from the one block of the components. Since the macroblock is variable-length coded, the length of each data is not uniform.

The shuffling process actually performed by the shuffling unit 16 will be schematically described with reference to FIGS. However, for simplicity, 9 frames per frame
Assume that only macroblocks are included.

In FIG. 6, the shuffling unit 16 randomly assigns each of the macro blocks MB1 to MB9 arranged in the scanning order to a memory map of an internal memory designated in advance according to the shuffling table data D14 supplied from the table generating unit 24. Is shuffled.

At this time, as shown in FIG. 7, the shuffling unit 16 stores each macro block, which is variable length data, into a fixed length frame (hereinafter referred to as a sync block) which is a unit when recording on the magnetic tape 20. ), And each overflow section MB5 ′, M
B2 'and MB3' are buffered once, and the macroblock M less than the sync block (the area with free space)
Each of the overflow blocks MB5 ', MB2', and MB3 'is sequentially packed after B8, MB1, MB7, and MB6, so that each of the fixed-length sync blocks SK1 to SK is packed.
9 is generated.

The shuffling section 16 reads out the respective sync blocks SK1 to SK9 in order from the upper or lower address, and reads them out in VLC (Variable Length Code) data D2.
To the ECC (Error Correctig Code) unit 17 (FIG. 2).

As shown in FIG. 8, the ECC unit 17 arranges the sync blocks SK1 to SK9 of the VLC data D2 supplied from the shuffling unit 16 two-dimensionally, and first operates in the vertical direction to execute the Reed-Solomon code. PB1 to PB3 (hereinafter, referred to as outer code data) are generated, and then operated in the horizontal direction to generate Reed-Solomon codes (hereinafter, referred to as inner code data) PB4 to PB7.

The ECC unit 17 outputs the outer code data PB
1 to PB3 and the inner code data PB4 to PB7 are added to the VLC data D2 to generate error correction code additional data D3, which is sent to the interleave unit 18 (FIG. 2).

The interleave unit 18 interleaves the interleave table data D1 set in step SP7.
5, each of the sync blocks SK1 to SK9, the outer code data PB1 to PB3, and the inner code data PB4 to PB7 of the error correction code ancillary data D3 supplied from the ECC unit 17 are stored in the internal memory designated in advance. Interleaving is performed by randomly writing to the memory map.

The main purpose of this interleaving is to disperse the effects of burst errors so that the error correction capability approaches the correction capability of random errors as much as possible, and to provide accurate error correction (for errors that cannot be corrected). Concealment).

Incidentally, a burst error is an error that occurs intensively without being independent for each bit, and a random error is an error that occurs irregularly for each bit. Further, error correction (concealment) is to perform an interpolation process using an error-free pixel near a visually degraded portion on a screen due to an error that cannot be corrected.

In the interleaved state, the interleaving section 18 randomly writes each of the sync blocks SK1 to SK9 and the outer code data PB1 to PB3
And the inner code data PB4 to PB7 are read out in order from the upper or lower address, and are recorded on the magnetic tape 20 via the magnetic head 19 as recording image data D4.

Thus, the CPU 10 proceeds to step S
The recording process in P9 is executed, and the next step SP10
Move on to

In step SP10, the CPU 10
It is determined whether the stop button of the input unit 13 has been pressed. If a negative result is obtained here, the CPU 10 returns to step SP9 and continues the recording process.

On the other hand, if a positive result is obtained, the CP
U10 stops the recording process and moves to the next step SP11.

In this case, in order for the video tape recorder 3 to reproduce the recorded image data D4 recorded on the magnetic tape 20, the data rearrangement pattern (shuffling table data D14 and It is necessary to recognize the interleave table data D15) and perform data rearrangement using a data rearrangement pattern opposite to the data rearrangement pattern.

Therefore, the CPU 10 executes the above-described step SP
5, the encrypted UMID data D1 once stored in the memory 12
2 and the encrypted data D16 and D17 once stored in the memory 12 in step SP8 described above must be transmitted to the video tape recorder 3.

In step SP11, the CPU 10
The encrypted UMID data D1 once stored in the memory 12
2. Read the encrypted data D16 and D17 from the memory 12 and read them from the IEEE 1394 interface 1.
1 to the video tape recorder 3 via the personal computer (not shown) and the Internet 4 (FIG. 1) sequentially, and then the process goes to step SP2 again to repeat the above processing.

As described above, the video camera 2 repeats the above-described encryption processing procedure of the routine RT1 every time the recording button of the input unit 13 is pressed, so that the recording button is pressed as shown in FIG. The recording image data D4 (D4A to D4A to D4A) generated by rearranging the data strings with different data rearranging patterns for each input material each time
D4N) are sequentially recorded on the magnetic tape 20.

Further, each time the recording button is pressed, the CPU 10 encrypts the UMID data D11 for specifying each input material with the encryption key D10, thereby encrypting the UMID data D12 (D12A to D12).
N) and converting the UMID data D11 to match the mathematical condition of the encryption key D10 to generate a material-specific encryption key D13 unique to each material,
By encrypting the corresponding data rearrangement pattern with the material specifying encryption key D13, the encrypted data D1 is obtained.
6 (D16A to D16N), D17 (D17A to D17)
N) can be generated.

As described above, the CPU 10 controls the recording image data D4 (D4A to D4N) recorded on the magnetic tape 20.
UMID data D12 (D12A to D12N) and encrypted data D16 (D16A to D16N), D17 (D1
7A to D17N) to the recording image data D4 (D4A to D4A).
D4N) and temporarily store them in the memory 12
After the recording process is completed, the data is transmitted to the video tape recorder 3 via the personal computer and the Internet 4 (FIG. 1).

Thus, the CPU 10 sets the recording image data D
4 (D4A to D4N), the data rearrangement pattern (shuffling table data D14 and interleave table data D15) corresponding to the encrypted data rearrangement pattern cannot be recognized by the video tape recorder 3. As long as it cannot be restored to the original material and cannot be reproduced, it is possible to encrypt each material as a result.

(3) Decoding procedure in video tape recorder Video tape recorder 3 having a circuit configuration as shown in FIG.
The decoding processing procedure according to the present embodiment will be described with reference to FIG.

This video tape recorder 3 has a CPU 3
0, IEEE139 for exchanging various information with another device (a personal computer in this embodiment)
4 interface 31, memory 32, HDD (hard disk drive) 33, various operation buttons (not shown)
And the like, and an encryption key D10 for transmitting to the video camera 2 and a key generation unit 40 for generating a decryption key D20 corresponding to the encryption key D10 via the data bus BUS. The CPU 30 performs predetermined processing in accordance with various programs read from the HDD 33 by the CPU 30 to control the video tape recorder 3 overall, and reproduces the loaded video cassette 5 via the reproducing unit 45. It has been made like that.

The key generation unit 40 generates a decryption key D20 corresponding to the encryption key D10 transmitted to the video camera 2, and records this in the HDD 33 in advance.

In practice, the CPU 30 proceeds from the start step of the decoding processing procedure according to the routine RT2 to the next step SP12.

At step SP12, the CPU 30
The encrypted UMID data D12A to D12N and the encrypted data D16A to D16N and D17A to D17N transmitted from the video camera 2 via the Internet 4 are IE
H obtained through the EE1394 interface 31
The data is stored in the DD 33, and the process proceeds to the next step SP13.

At step SP13, the CPU 30
It is determined whether the play button of the input unit 34 has been pressed. Here, if a negative result is obtained, the CPU 30 waits until the play button is pressed. On the other hand, when a positive result is obtained, the CPU 30 proceeds to the next step SP14.

At step SP14, the CPU 30
The decryption key D20 stored in the HDD 33 in advance is stored in the UM
The ID is transmitted to the ID decryption unit 41 and the material identification decryption key generation unit 42.

Then, the CPU 30 sends the encrypted UMID data D12A corresponding to the recorded image data D4A which is the material to be reproduced first among the encrypted UMID data D12A to D12N stored in the HDD 33 to the UMID decryption unit 41 and encrypts the data. The data D16A and D17A are sent to the material specifying decryption key generation unit 42, and the next step SP
Move to 15.

At step SP15, the CPU 30
The UMID decryption unit 41 uses the encrypted UMID data D12
A is decrypted with the decryption key D20 supplied from the HDD 33 so that the original UMID data D1
1 is restored and sent to the material specifying decryption key generation unit 42, and the routine goes to the next step SP16.

At step SP16, the CPU 30
The UMID data D1 is generated by the material identification decryption key generation unit 42.
1 in accordance with the mathematical condition based on the decryption key D20, the material identification decryption key D2 corresponding to the material identification encryption key D13 generated in the video camera 2.
1 is transmitted to the table decoding unit 43, and the process proceeds to the next step SP17.

At step SP17, the CPU 30
The encrypted data D16A and D17A are decrypted by the table decryption unit 43 using the material-specific decryption key D21 supplied from the material-specific decryption key generation unit 42, respectively. The ring table data D14 and the interleave table data D15 are restored, and the routine goes to the next step SP18.

At step SP18, the CPU 30
The de-shuffling table data D22 and the de-interleave table data D23, which are data reversion patterns respectively corresponding to the shuffling table data D14 and the interleave table data D15, are read from the HDD 33.

The CPU 30 sends the deshuffling table data D22 to the deshuffling unit 36 and sends the deinterleaving table data D23 to the deinterleaving unit 38, so that the deshuffling unit 36 and the deinterleaving unit 38 The data reversion pattern is set, and the routine goes to step SP19.

At step SP19, the CPU 30
When the reproduction button is pressed, the first recorded image data D4A reproduced from the magnetic tape 20 of the video cassette 5 (FIG. 1) via the magnetic head 39 is input to the deinterleave section 38.

The deinterleaving section 38 performs deinterleaving on the recording image data D4A in accordance with the deinterleaving table data D23 set in the above-mentioned step SP18 so as to have a pattern opposite to the interleaving, thereby obtaining the original error correction code added data D3. Is restored and sent to the ECC unit 37.

The ECC unit 37 includes a deinterleave unit 38
After performing the error correction process using the inner code data PB4 to PB7 (FIG. 8) of the error correction code additional data D3 supplied from, the error correction process using the outer code data PB1 to PB3 (FIG. 8) is also performed. The original VLC data D2 is restored and sent to the deshuffling unit 36.

The deshuffling unit 36 converts the VLC data D2 supplied from the ECC unit 37 into the above-mentioned step SP1.
In accordance with the deshuffling table data D22 set in step S8, the original elementary stream D1 is subjected to deshuffling having a pattern opposite to shuffling.
And output this to an external monitor.

If the data rearrangement pattern cannot be recognized, the reproducing unit 45 cannot restore the recorded image data D4 to the original elemental stream D1, and as a result, the external monitor not only deteriorates the image quality but also reproduces the image. Will display an image that cannot be recognized.

Thus, the CPU 30 proceeds to step S
In P19, recorded image data D corresponding to the first material
4A is executed, and the next step SP20
Move on to

At step SP20, the CPU 30
It is determined whether or not the recorded image data D4A reproduced from the magnetic tape 20 of the video cassette 5 has become the recorded image data D4B corresponding to the next new material.

If a positive result is obtained here, this means that the reproduction of the first recorded image data D4A among the plurality of recorded image data D4 recorded on the magnetic tape 20 of one video cassette 5 (FIG. 1). At this time, the CPU 30 returns to step SP14 again and returns the encryption UMID corresponding to the next new recording image data D4B.
The data D12B and the encrypted data D16B and D17B are converted into a UMID decryption unit 41 and a material identification decryption key generation unit 42.
, And the above-described processing is repeated to execute the reproduction processing for the recorded image data D4B corresponding to the new material.

As described above, every time the recorded image data D4 (D4A to D4N) corresponding to each material is sequentially reproduced, the CPU 30 sets the encrypted UMID data D12 (D12A to D12N) corresponding to the next material and the encrypted data. Data D1
6 (D16A to D16N) and encrypted data D17 (D1
7A to D17N) are sent to the UMID decryption unit 41 and the material identification decryption key generation unit 42, and the above processing is repeated.
Reproduction processing is performed on the recorded image data D4 (D4A to D4N).

On the other hand, if a negative result is obtained, it means that the reproduction of the recorded image data D4A corresponding to the first material recorded on the magnetic tape 20 has not been completed. Is the next step SP2
Move to 1.

At step SP21, the CPU 30
It is determined whether the magnetic tape 20 of the video cassette 5 (FIG. 1) has been reproduced to the end. If a negative result is obtained here, this means that the reproduction of all the recorded image data D4A to D4N has not been completed yet and is being reproduced, and at this time, the CPU 30 returns to step SP19 again. Continue the playback process.

On the other hand, if a positive result is obtained, it means that the reproduction of all the recorded image data D4A to D4N, which is the material recorded on the magnetic tape 20 of the video cassette 5, has been completed. At this time, the CPU 30 stops the reproduction processing, moves to step SP22, and ends the decoding processing procedure.

As described above, the CPU 30 converts the encrypted UMID data D12A to D12N and the encrypted data D16A to D16N and D17A to D17N necessary for reproducing the recorded video data D4A to D4N corresponding to each material into I.
Acquired via the EEE1394 interface 31,
Each time the recorded video data D4A to D4N are sequentially reproduced, the encrypted UMID data D corresponding to the recorded image data D4
12 is decrypted with the decryption key D20, and the encrypted data D16 and D17 corresponding to the material are sequentially decrypted with the material specifying encryption key D13 based on the UMID data 11 obtained by decrypting the original data rearrangement pattern. Certain shuffling table data D14 and interleave table data D15 can be restored.

As a result, the CPU 30 sets the shuffling table data D14 and the interleave table data D
The recording video data D4A to D4N recorded on the magnetic tape 20 of one video cassette 5 using the deshuffling table data D22 and the deinterleaving table data D23 which are the data reversion patterns corresponding to No. 15 for each material. Playback can be performed sequentially.

In the above configuration, the video camera 2 in the network-compatible encryption system 1 uses the U for specifying each material each time the material is input.
The MID data D11 is generated, and the UMID data D11 corresponding to each material is converted to match the mathematical condition of the encryption key D10, thereby generating a material-specific encryption key D13 unique to each material.

The material-specific encryption key D13 is converted so that unique information (material number included in the UMID data D11), which is hard to guess for each material, matches the mathematical condition of the encryption key D10. For a third party, the material identification encryption key D based on the algorithm of the encryption key D10 and the UMID data D11 specified for each material.
13 and information that cannot be decoded unless all the unique information (material number) included in the UMID data D11 is known.

Then, the video camera 2 uses the material specifying encryption key D13 to execute different data rearrangement patterns (shuffling table data D14) corresponding to each material.
And the interleave table data D15), respectively, to generate encrypted data D16 and D17 corresponding to each material.

Here, the data rearrangement pattern is for rearranging the materials in the process before being recorded and recorded on the magnetic tape 20, and the data rearrangement pattern must be known for the video tape recorder 3 to reproduce. If it is not possible to restore the original material, it is indispensable information for reproducing the recorded image data D4.

Therefore, the video camera 2 obtains the same effect as that obtained by encrypting the recorded image data D4 only by encrypting the data rearrangement pattern having a data amount much smaller than that of the recorded image data D4 itself. be able to.

In addition, since the video camera 2 encrypts with the material specifying encryption key D13 corresponding to the data rearrangement pattern generated for each material, even if one piece of encrypted data is decrypted, Since all the remaining encrypted data are decrypted one by one, it is possible to prevent all the remaining encrypted data from being immediately decrypted as a result.

On the other hand, the video tape recorder 3 in which the decryption key D20 corresponding to the encryption key D10 in the network-compatible encryption system 1 is stored in advance therein, every time the elementary stream D1 as a material is input. UM generated to identify each material
The ID data D11 and the encrypted data D16 and D17 generated by encrypting the data rearrangement pattern with the material-specific encryption key D13 unique to each material based on the UMID data D11 are transmitted from the encryption device. The UMID data D11 corresponding to each material is converted to match the mathematical condition of the encryption key D10 to generate a material-specific decryption key D21, and the material-specific decryption key D21 is used to generate the encrypted data D16. And D17, respectively, the original data rearrangement pattern before being encrypted by the encryption device can be restored.

According to the above configuration, in the video camera 2 in the network-compatible encryption system 1, every time each material is input, the UMID data D11 for specifying each material is converted into a mathematical expression of the encryption key D10. The data rearrangement patterns (shuffling table data D14 and interleave table data D15) are each encrypted with a material-specific encryption key D13 unique to each material obtained by performing conversion in accordance with the dynamic conditions. Thus, for a third party, the algorithm of the encryption key D10 and the UMID data D11 specified for each material
A conversion pattern to be converted to a material specifying encryption key D13 based on the UMID data D11 and a material specifying encryption key D13 that cannot be decrypted unless all of the unique information (material number) included in the UMID data D11 are known are generated. Thus, it is possible to prevent the data rearrangement pattern from being easily decoded by a third party.

In the present embodiment, a network compatible encryption as an encryption system for transmitting the encrypted UMID data D12 and the encrypted data D16 and D17 from the video camera 2 to the video tape recorder 3 via the Internet 4. Although the description has been given of the case where the present invention is applied to the computerized system 1, the present invention is not limited to this.
In place of this, a wired and wireless communication medium such as digital satellite broadcasting may be used. Also, as shown in FIG. 12, a package media-compatible encryption system 50 in FIG. Alternatively, the encrypted UMID data D12 and the encrypted data D16 and D17 may be transferred from the video camera 2 to the video tape recorder 3 via the memory card 51.

In this case, in the network-compatible encryption system 1, the CPU 30 (see FIG.
0) is the encrypted UMID data D12 and the encrypted data D16
And D17 are obtained from the IEEE 1394 interface 31, but in the package media-compatible encryption system 50, the CPU 30 as an obtaining unit
The information may be obtained via a memory card interface as a reading unit instead of the EE1394 interface 31.

In the above-described embodiment, the CPU 10 and the UMID generation unit 21 as unique information generation means
Has described a case where a UMID is generated as unique information and UMID data D11 is extracted from the UMID. However, the present invention is not limited to this. Any unique information generating means may be used. By doing so, it is possible to specify image data as a material with a much smaller data amount.

Further, in the above embodiment, the CP
The case where the encryption key generation means is constituted by the U10 and the material identification encryption key generation unit 23 and the decryption key generation means is constituted by the CPU 30 and the material identification decryption key generation unit 42, but the present invention is not limited thereto. The encryption key generation unit and the decryption key generation unit may be configured by other various circuit configurations.

Further, in the above-described embodiment, the CPU 10 as the encryption means and the table encryption unit 25 encrypt the data rearrangement pattern to be encrypted, thereby generating the encrypted data D16 and D17. CPU 30 serving as encryption / decryption means and table decryption unit 4
3 has described the case where the original data rearrangement pattern is restored by decrypting the encrypted data D16 and D17. However, the present invention is not limited to this case. The inputted image data itself as the material to be encrypted may be encrypted, and the decryption means material may decrypt the encrypted image data as the material.

In this case, the information to be transmitted to the video tape recorder 3 via the Internet 4 is an encrypted UM
Only ID data D11 is sufficient.

Further, in the above-described embodiment, the CPU 10 as the transmitting means and the IEEE1394 interface 11 are connected to the UMID data D11 as the unique information.
UMID data D generated by encrypting
12, the case where the encrypted data D16 and D17 are transmitted, and the CPU 30 and the IEEE1394 interface 31 as the receiving means receive the encrypted UMID data D12 and the encrypted data D16 and D17 has been described, but the present invention is not limited to this. The transmitting means and the receiving means for transmitting at least the unique information and the encrypted data may be used.

Further, in the above-described embodiment, the case where the encryption key D10 and the decryption key D20 according to the RSA of the asymmetric encryption method are used has been described. However, the present invention is not limited to this. DES (Data Encr
For example, an encryption key and a decryption key according to various other encryption algorithms may be used, such as using an encryption key and a decryption key according to the yption standard. In this way, it is possible to efficiently select the characteristics of various encryption algorithms according to the situation in which the Internet-compatible encryption system 1 is constructed.

Furthermore, in the above-described embodiment, the case where image data is applied as a material has been described. However, the present invention is not limited to this, and various other data 0 such as audio data may be used as a material. Can be.

Further, in the above-described embodiment, the case where the video camera 2 as the encryption device and the video tape recorder 3 as the decryption device are applied has been described. However, the present invention is not limited to this. Editing device for editing materials such as audio and audio data, CD (Compact
The present invention can be widely applied to various other encryption devices and decryption devices such as a disk player and a personal computer.

[0103]

As described above, according to the present invention, each time each material is input, unique information for specifying each material is generated, and the unique information corresponding to each material is converted into a predetermined format. By generating a unique encryption key for each material, and encrypting each material or predetermined information corresponding to each material with the encryption key. It is possible to generate an encryption key for each unique material that cannot be decrypted at all by a third party unless all is known, thus preventing the encryption target from being easily decrypted by the third party Can be.

Further, as predetermined information corresponding to each material, a data rearrangement pattern for rearranging each material in a predetermined data amount unit each time each material is input is encrypted. Thus, the data can be encrypted with a much smaller amount of data than when the material itself is encrypted.

Further, as described above, according to the present invention, each time each material is input, unique information generated for specifying each material and an encryption code unique to each material based on the unique information are obtained. Encrypting each material or predetermined information corresponding to each material with the encryption key, and obtaining encrypted data generated from the encryption device, and converting the unique information corresponding to each material according to a predetermined method. By generating a decryption key for decrypting the encrypted data respectively, decrypting the encrypted data with the decryption key and restoring each material or predetermined information corresponding to each material, it is difficult to analogize. It is possible to obtain a unique information and an encryption key for each unique material that cannot be decrypted by a third party because it is generated based on the unique information, and generate a decryption key. , Sure And accurately it is possible to restore the predetermined information corresponding to each element or each material.

Further, as described above, according to the present invention, each time each material is input, unique information for specifying each material is generated, and the unique information corresponding to each material is converted according to a predetermined method. After conversion, a unique encryption key is generated for each material, and each material or predetermined information corresponding to each material is encrypted with the encryption key to generate encrypted data, and the encrypted data and unique information are generated. And a decryption key for receiving the encrypted data and the unique information, converting the unique information corresponding to each material according to a predetermined method, and decrypting the encrypted data. By generating an encryption / decryption device that decrypts the encrypted data with the decryption key and restores each material or predetermined information corresponding to each material, the encryption device includes: Kind Unless all the difficult-to-understand unique information is known, it is possible to generate an encryption key for each unique material that cannot be decrypted by a third party, so that the encryption target can be easily decrypted by the third party In the encryption / decryption device, unique information that cannot be easily analogized via the transmission unit and unique information that cannot be decrypted by a third party because it is generated based on the unique information can be prevented. Since the decryption key can be generated by receiving the encryption key for each material, it is possible to reliably and accurately restore each material or each piece of predetermined information corresponding to each material.

Further, as described above, according to the present invention, each time each material is input, unique information for specifying each material is generated, and the unique information corresponding to each material is converted according to a predetermined method. After conversion, a unique encryption key is generated for each material, and each material or predetermined information corresponding to each material is encrypted with the encryption key to generate encrypted data, and the encrypted data and unique information are generated. And an encryption device for storing the encrypted data and the unique information from the storage medium, and converting the unique information corresponding to each material according to a predetermined method into encrypted data. A decryption key for generating a decryption key for decryption and decrypting the encrypted data with the decryption key to restore each material or predetermined information corresponding to each material is constructed. As a result, the encryption device can generate an encryption key for each unique material that cannot be decrypted at all by a third party unless all the unique information that is difficult to guess is known. This makes it possible to prevent the decryption target from being easily decrypted. In the decryption device, since the unique information read from the storage means is difficult to guess, and is generated based on the unique information, Can receive an encryption key for each unique material that cannot be decrypted at all and generate a decryption key,
Each material or predetermined information corresponding to each material can be reliably and accurately restored.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a network-compatible encryption system according to the present invention.

FIG. 2 is a block diagram illustrating a configuration of a digital video camera recorder.

FIG. 3 is a flowchart illustrating an encryption processing procedure.

FIG. 4 is a schematic diagram illustrating a data structure of a UMID.

FIG. 5 is a schematic diagram illustrating a data rearrangement pattern determination screen.

FIG. 6 is a schematic diagram for explaining a shuffling process;

FIG. 7 is a schematic diagram for explaining a shuffling process;

FIG. 8 is a schematic diagram used for description of Reed-Solomon code generation.

FIG. 9 shows recorded image data recorded for each material and an encryption U
FIG. 4 is a schematic diagram illustrating a correspondence relationship between MID data and encrypted data.

FIG. 10 is a block diagram showing a configuration of a digital video tape recorder.

FIG. 11 is a flowchart illustrating a decoding processing procedure.

FIG. 12 is a schematic diagram illustrating a configuration of a package media-compatible encryption system according to another embodiment.

[Explanation of symbols]

1, 50 ... Network compatible encryption system, 2 ...
... video camera, 3 ... video tape recorder, 4 ...
Internet, 5 ... Video cassette, 10, 30 ...
... CPU, 11, 31 ... IEEE 1394 interface, 12, 32 ... memory, 13, 34 ... input unit, 14 ... display unit, 16 ... shuffling unit, 17,
37 ECC part, 18 Interleave part, 19
39: magnetic head, 20: magnetic tape, 21: U
MID generation unit, 22 UMID encryption unit, 23 material-specific encryption key generation unit, 24 table generation unit, 25
...... Table encryption unit, 27 ... Recording unit, 33 ... HD
D, 36: deshuffling unit, 37: deinterleave unit, 40: key generation unit, 41: UMID decryption unit, 42: material specific decryption key generation unit, 43: table decryption unit, 45 ...... Reproduction unit.

Claims (14)

[Claims] 1. A unique information generating means for generating unique information for specifying each material each time each material is input, and converting the unique information corresponding to each material according to a predetermined method. Encryption key generation means for generating an encryption key unique to each material, and encrypting each material or predetermined information corresponding to each material with the encryption key corresponding to each material. And an encryption means for encrypting. 2. The method according to claim 1, wherein the predetermined information corresponding to each material is a data rearrangement pattern in which each material is rearranged in a predetermined data amount unit each time the material is input. The encryption device according to claim 1. 3. The encryption apparatus according to claim 1, wherein the unique information generation means generates the unique information by multiplying at least management information for managing the encryption apparatus by a random number. . 4. A unique information generating step for generating unique information for specifying each material each time each material is input, and converting the unique information corresponding to each material according to a predetermined method. An encryption key generating step of generating an encryption key unique to each material, and encrypting each material or predetermined information corresponding to each material with the encryption key corresponding to each material. Encryption step. 5. The method according to claim 1, wherein the predetermined information corresponding to each material is a data rearrangement pattern for rearranging each material in a predetermined data amount unit each time the material is input. The encryption method according to claim 4. 6. The encryption method according to claim 4, wherein the unique information generating step generates the unique information by multiplying at least management information for managing the encryption device by a random number. . 7. Each material or each of the above-mentioned materials is specified by a unique information generated for specifying each material each time each material is input, and an encryption key unique to each material based on the unique information. Acquiring means for acquiring, from the encryption device, encrypted data generated by encrypting predetermined information corresponding to each material from the encryption device; and converting the unique information corresponding to each material according to a predetermined method. Decryption key generating means for generating a decryption key for decrypting the encrypted data, and decrypting the encrypted data with the decryption keys respectively corresponding to the materials. An encryption / decryption device comprising: an encryption / decryption unit that restores each of the materials or predetermined information corresponding to each of the materials. 8. Each material is input by using unique information generated for specifying each material, and an encryption key unique to each material based on the unique information. An acquisition step of acquiring, from the encryption device, encrypted data generated by encrypting predetermined information corresponding to each material from the encryption device; and converting the unique information corresponding to each material according to a predetermined method. A decryption key generating step of generating a decryption key for decrypting the encrypted data, and decrypting the encrypted data with the decryption keys respectively corresponding to the materials. An encryption / decryption step of restoring each material or predetermined information corresponding to each material. 9. An encryption system constructed by an encryption device and an encryption / decryption device, wherein the encryption device generates unique information for specifying each material each time the material is input. Unique key generating means for generating a unique encryption key for each material by converting the unique information corresponding to each material according to a predetermined method; and Encryption means for generating encrypted data by respectively encrypting each material or predetermined information corresponding to each material with the corresponding encryption key, and the unique information respectively corresponding to each material. Transmitting means for transmitting the encrypted data, the encryption / decryption device comprising: a receiver for receiving the unique information and the encrypted data respectively corresponding to the respective materials; And a decryption key generating means for generating a decryption key for decrypting the encrypted data by converting the unique information corresponding to each of the materials according to a predetermined method. An encryption / decryption means for respectively decrypting the encrypted data with the corresponding decryption key to restore the material or predetermined information corresponding to the material. system. 10. The method according to claim 1, wherein the predetermined information corresponding to each material is a data rearrangement pattern for rearranging each material in a predetermined data amount unit each time the material is input. An encryption system according to claim 9. 11. The encryption system according to claim 9, wherein said unique information generating means generates said unique information by multiplying at least management information for managing said encryption device by a random number. . 12. An encryption system constructed by an encryption device and an encryption / decryption device, wherein the encryption device generates unique information for specifying each material each time the material is input. Unique key generating means for generating a unique encryption key for each material by converting the unique information corresponding to each material in accordance with a predetermined method; and Encrypting means for generating encrypted data by respectively encrypting each material or predetermined information corresponding to each material with the corresponding encryption key, and the unique information respectively corresponding to each material. Storage means for recording the encrypted data on a predetermined storage medium, wherein the encryption / decryption device includes the unique information respectively corresponding to the respective materials from the storage medium. Reading means for reading the encrypted data; and a decryption key for generating a decryption key for decrypting the encrypted data by converting the unique information corresponding to each material according to a predetermined method. Generating means, and encryption / decryption means for restoring the material or predetermined information corresponding to the material by decrypting the encrypted data with the decryption key corresponding to the material. An encryption system characterized by 13. A method according to claim 1, wherein the predetermined information corresponding to each material is a data rearrangement pattern for rearranging each material in a predetermined data amount unit each time the material is input. The encryption system according to claim 12. 14. The encryption system according to claim 12, wherein said unique information generating means generates said unique information by multiplying at least management information for managing said encryption device by a random number. .