JPH0879234A - Data receiver - Google Patents

Abstract

PURPOSE: To provide a data receiver suitable for charging for deciphering and storage of signals capable of receiving and deciphering or storing enciphered signals while protecting a copyright. CONSTITUTION: An arithmetic operation is performed to the initial value of a cipher separated in a reception separation circuit 111 in an arithmetic circuit 112 and a key signal is calculated. The calculated key signal is enciphered in an encipherment circuit 115 by using a user ID stored in a memory 113 and it is multiplexed with main data in a multiplex circuit 116 and recorded and stored in a data storage device 140. The signals inputted from the data storage device 140 are separated into the main data and the key signal in a separation circuit 117 and the key signal is deciphered by using the user ID of the memory 113 in a first deciphering circuit 118. Further, a pseudo random number is generated in a random number generation circuit 120 to which the key signal is inputted and the main data ciphered in a transmission station are deciphered in a second deciphering circuit 121 by using the pseudo random number.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data receiving device for receiving and storing a binary coded signal, and more particularly, while protecting the copyright of the encrypted signal when it is received. The present invention relates to a data receiving apparatus that enables decoding or storage of signals and is suitable for charging for decoding and storage of signals.

[0002]

2. Description of the Related Art Encryption and decryption of video and audio signals,
The technology related to the charging system is described in, for example, "Journal of Television Society"; Vol. 46, No. 1 (January 1992), pp. 31-39.

[0003]

The above-mentioned paper describes a technique relating to encryption and decryption of a video signal and an audio signal in a satellite communication service, and a charging system. However, there is no disclosure of a method and a technique that enable signal accumulation while protecting the copyright of the received signal and charge for decoding and accumulation of the signal.

An object of the present invention is to enable an encrypted signal to be received and decoded or stored while protecting the copyright, and a data receiving apparatus suitable for billing for the decoding and storage of the signal. To supply.

[0005]

In order to achieve the above object, the first data receiving apparatus according to the present invention inputs an encrypted signal and uses it for decryption of main data and encryption of the main data. The input signal separating means for separating the initial value necessary for generating the key signal and the user identification code are stored, and after confirming the signal reception permission for the user of this device by this user identification code, the input signal separating means Operation that uses the output initial value to generate the key signal required for decryption of the encryption of the main data, and the key signal generated by the operation / memory circuit that is stored in the operation / memory circuit From the data storing means, the data storing means for storing / storing the encrypting means for encrypting using the person identification code, the main data separated by the input signal separating means and the key signal encrypted by the encrypting means. Is output Using the first decoding means for decoding the encryption of the encrypted key signal using the user identification code stored in the arithmetic / memory circuit, and the key signal decoded by the first decoding means, Second decryption means for decrypting the encryption of the main data output from the data storage means.

Alternatively, in order to achieve the above object, the second data receiving apparatus according to the present invention inputs an encrypted signal and is necessary for generating main data and a key signal used for decryption of the encryption of the main data. The input signal separating means for separating the input signal separating means, the main data output from the input signal separating means, and the initial value output from the input signal separating means.
A data storage device for storing and a user identification code are stored,
After confirming the signal reception permission to the user of this device by this user identification code, by using the initial value output from the data storage device, an arithmetic / memory circuit for generating a key signal necessary for decryption of the encryption of the main data And a decryption unit that decrypts the encryption of the main data output from the data storage unit using the key signal calculated by the arithmetic / memory circuit.

[0007]

In the first data receiving apparatus according to the present invention, the input signal separating means is first a wired communication or a satellite wave,
Receives signals transmitted using wireless communication such as terrestrial,
The main data encrypted to prevent unauthorized reception by non-contractors and the initial value that generates the key signal necessary for decrypting the main data are separated, the main data is stored in the data storage means, and the initial value is calculated. -Output to the memory circuit respectively.

In the operation / memory circuit, after confirming the signal reception permission for the receiving contractor who uses this apparatus by using the preset identification code of the operation / memory circuit, the signal is output from the input signal separating means. The calculated initial value is calculated and a key signal is generated. In this arithmetic / memory circuit, if the device is owned by a user who is not licensed by the signal supplier, the correct key signal cannot be obtained by the arithmetic operation from the initial value. That is, the non-contractor cannot decrypt the encryption of the main data.

The key signal output from the arithmetic / memory circuit is then input to the encryption means, where the identification code of the arithmetic / memory circuit output from the arithmetic / memory circuit
Encrypted. Here, the identification code indicates that the supplier of the received signal permits the receiving contractor to receive the signal, and at the same time, it is added to distinguish this device from other similar data receiving devices. It is a sign. The encrypted key signal output from the encryption means is input to the data storage means together with the main data output from the input signal separation means, whereby the signal can be stored.

On the other hand, the main data output from the data storage means is sent to the second decryption means, and the encrypted key signal is sent to the first decoding device together with the identification code stored in the arithmetic / memory circuit.
Is input to each of the decryption means.

The first decoding means uses the identification code to
Decrypt the encrypted key signal. Here, the main calculation
Only the signal encrypted by using the memory circuit can be correctly decrypted. That is, since the identification code unique to the arithmetic / memory circuit is used for encryption of the key signal, even if the device is capable of signal processing similar to this device, it is encrypted by the device having an identification code different from this device. The received signal is not correctly decoded by this device.

Next, the key signal decrypted by the first decryption means is input to the second decryption means together with the main data output from the data storage means. In this second decoding means,
The key signal output from the first decryption means is used to decrypt the main data output from the data storage means, that is, the main signal is encrypted to prevent unauthorized reception by a non-contractor. Cancel. Therefore, only when the key signal can be correctly decrypted by the first decryption means, the main data can be properly decrypted by the second decryption means.

According to this device using the above-mentioned means, the signal encrypted and stored by this device can be decrypted only by this device, and conversely, it can be encrypted and encrypted by a device different from this device. The accumulated signal cannot be decoded by this device. That is, for example, to the data storage means using a tape-shaped or disk-shaped magnetic recording medium,
Accurate storage of received signals is possible only when the user himself / herself who has received a license uses a specific device, and when the transfer is transferred to a third party by copying using a storage medium, It becomes impossible to correctly decode the signal, and thus it is possible to prevent the copyright of the signal supplier from being infringed.

In the second data receiving apparatus according to the present invention, the input signal separating means first receives a signal transmitted by using wired communication or wireless communication such as satellite wave, terrestrial wave, etc. By separating the main data encrypted to prevent unauthorized reception and the initial value that generates the key signal necessary for decrypting the main data, and outputting the main data and the initial value to the data storage device, It is possible to store received signals.

On the other hand, the main data output from the data storage device is input to the decrypting means, and the initial value of the key signal is input to the arithmetic / memory circuit.

In the arithmetic / memory circuit, the initial identification code output from the data storage device is used after confirming the signal reception permission to the receiving contractor who uses this device, using the preset identification code of this arithmetic circuit. The value is calculated and a key signal is generated. In this arithmetic / memory circuit, if the device is owned by a user who is not licensed by the signal supplier, the correct key signal cannot be obtained by the arithmetic operation from the initial value. That is, the non-contractor cannot decrypt the encryption of the main data.

Next, the key signal output from the arithmetic / memory circuit is input to the decrypting means. In this decryption means, using the key signal output from the arithmetic / memory circuit,
The main data output from the data storage means is decrypted, that is, the main signal is decrypted to prevent unauthorized reception by non-contractors.

According to this device using the above-mentioned means, the signal accumulated by this device can be decoded only by this device, and conversely, the signal accumulated by the device different from this device is It becomes impossible to decrypt with this device. That is, the correct decoding of the received signal stored in the data storage means using, for example, a tape-shaped or disk-shaped magnetic recording medium can be performed only when the user who has received the reception uses a specific device. If it is possible to transfer it to a third party by copying it using a storage medium, it becomes impossible to correctly decode the signal, and therefore the copyright etc. of the signal supplier is infringed. It can be prevented.

[0019]

The details of the present invention will be described below with reference to the illustrated embodiments. Each of the following embodiments is an example of application to a multi-channel pay digital broadcast receiving terminal using a communication satellite or the like. Further, as a data storage device, a video tape recorder (hereinafter referred to as VT) capable of digital recording / reproduction
The case where R) is used is shown.

First, a multi-channel pay digital broadcasting system using a communication satellite including a receiving terminal, which is an application example of the data receiving apparatus according to the present invention, and a charging method will be briefly described with reference to FIG.

In FIG. 2, 201 is a broadcasting station that carries out multi-channel pay digital broadcasting using communication satellites.
Reference numeral 202 is a communication satellite, 203 is a receiving terminal for receiving multi-channel pay digital broadcasting, 211 is a communication line capable of bidirectional communication between the broadcasting station 201 and the receiving terminal 203 such as a telephone line, and 212 is a broadcasting station (ground station). Reference numeral 213 is a communication line connecting the communication satellite 202 with 201, and 213 is a communication line connecting the communication satellite 202 with the receiving terminal 203.

A user who wants to receive a multi-channel pay digital broadcasting service first needs to send mail or a communication line 211.
Apply for subscription to the broadcasting station 201 via the internet, etc., and at the same time, pay the subscription fee through a financial institution or the like with which the broadcasting station 201 is affiliated. Broadcast station 201 that confirmed the subscription application
Assigns a user identification number (hereinafter referred to as user ID) to the user and sends the user, for example, a dedicated terminal in which the user ID is registered or a dedicated IC card in which the user ID is registered. The user can open the receiving terminal 203 and receive the service by using the sent dedicated terminal or by mounting the dedicated IC card on the general-purpose receiving terminal.

For example, in multi-channel pay digital broadcasting using the information compression technique, the number of channels is used to make a time-shift broadcasting in which the same program is broadcast on a plurality of channels with a fixed start time at regular intervals. Or Video On Demand (hereinafter referred to as VOD) that broadcasts a program in response to a request from the receiving terminal side.
It becomes possible to supply new services such as. Further, since the signal itself is a digital signal, deterioration does not occur in the process of transmission / reception, and therefore high quality information can be obtained.

However, the fact that no deterioration occurs in transmission / reception means that it is possible to easily obtain a copy of the same quality as the original, and in the case where a large number of copies are produced without the permission of the copyright holder, The copyright of the signal supplier may be infringed and the normal pay broadcasting operation may be broken. Therefore, the broadcasting station 201 needs to scramble the program to be transmitted, that is, encrypt the signal to be transmitted, in order to protect the copyright of the signal supplier and operate the pay broadcasting normally.

From the above, in the broadcasting station 201,
It scrambles each signal such as sports relay and sends it. The communication satellite 202, which has received this via the communication line 212, performs processing such as conversion of the carrier frequency from the up line to the down line, and the receiving terminal 2 via the communication line 213.
A signal is transmitted to a predetermined service area including 03. Receiving terminal 20 that receives radio waves from communication satellite 202
3 (dedicated terminal provided by broadcasting station 201 or dedicated I
A receiving terminal opened by mounting the C card) can descramble the signal and view the program.

Then, the broadcasting station 201 checks the viewing status of the pay program at the receiving terminal 203 via, for example, the communication line 211 and charges for each contract month, each contract channel, each program viewed, etc. To collect viewing fees via.

Next, an example of the configuration of the broadcasting station 201 shown in FIG. 2 will be briefly described with reference to FIG.

In FIG. 3, 301 is an input terminal, and FIG.
Subscription request or program request from the receiving terminal 203 of
Alternatively, information such as viewing status for billing is received from the bidirectional communication line 211. An output terminal 302 is shown in FIG.
The compressed and multiplexed program is transmitted to the communication satellite 202. Reference numeral 311 is a reproducing device, which is, for example, a VTR, a magneto-optical disk device, an optical disk device, a hard disk device, a large capacity memory array device, or the like, and reproduces a program. Three
Reference numeral 12 denotes a compression circuit, which compresses information of reproduced video and audio signals. A time division multiplexing circuit 313 multiplexes the compressed signal in a time division manner. 314 is an information management device,
It manages the programs to be sent, user information, and the initial values of key signals necessary for encrypting signals, all at once. Three
Reference numeral 15 denotes a cipher generation circuit, which generates a key signal for encrypting the compressed signal multiplexed by the time division multiplexing circuit 313 by applying a specific operation to an initial value, and further generates a pseudo random number based on this key signal. Generate. Reference numeral 316 is an encryption circuit, which uses the pseudo random number from the encryption generation circuit 315 to generate the time division multiplexing circuit 3
The compression multiplexed signal from 13 is encrypted. A multiplexing circuit 317 multiplexes the compressed signal with the initial value of the encryption key signal, user individual information, and the like. Reference numeral 318 denotes a transmission circuit, which performs processing such as signal modulation for transmitting a program to a communication satellite. A customer information database 319 manages customer information.

Next, of the multi-channel pay digital broadcasting using communication satellites capable of various new services, VOD is taken as an example of the service, and the internal configuration of the broadcasting station 201 of FIG. 3 will be described. To do.

In the broadcasting station 201 which has received the request from the receiving terminal 203 of FIG. 2 via the communication line 211 and the input terminal 301, the information management device 314 first searches the customer information database 319 and transmits the request. Whether or not the user is a regular subscriber, the payment status of the viewing fee, and the like are confirmed, and when the program can be provided to the user who has transmitted the request, the playback device 311 is used.
Play the requested program. The program reproduced by the reproduction device 311 is compressed by the compression circuit 312 by an optimum compression method according to the characteristics of information such as MPEG system in the case of video and audio, and the other by the time division multiplexing circuit 313. It is time-division multiplexed with a compressed signal such as a program requested by the user.

The information management device 314 manages an initial value for generating a key signal necessary for signal encryption, and outputs the initial value to the cipher generation circuit 315. The cipher generation circuit 315 performs a calculation based on the initial value received from the information management device 314 to calculate a key signal, and further generates data necessary for signal encryption, such as a pseudo-random number.

The encryption circuit 31 is based on the above pseudo random number.
At 6, the signal is encrypted by, for example, a process such as an exclusive OR of the compression-multiplexed signal and the pseudo random number, or a line rotation based on the pseudo random number. Next, in the multiplexing circuit 317, the initial value of the key signal,
Individual information for the user, program information, etc. are multiplexed with the compressed signal. Although omitted here, the multiplexing circuit 31
By encrypting the initial value of encryption, individual information, program information, etc., which are multiplexed in step 7, it is possible to protect customer privacy, prevent illegal decryption of encryption, etc., and further improve system security.

The sending circuit 318 adds an error correction code, packetizes the data, and performs a modulation process for transmission to the communication satellite 202, and outputs the signal to the output terminal 302 and the communication line 2.
12, through the communication satellite 202, and the communication line 213,
The encrypted signal is transmitted to the receiving terminal 203.

Next, an example of the internal configuration of the multi-channel pay digital broadcast receiving terminal 203 utilizing the communication satellite shown in FIG. 2 will be described with reference to FIG.

In FIG. 1, reference numeral 100 denotes a receiving terminal corresponding to 203 in FIG. 2, which receives a signal from a broadcasting station and performs signal processing. An input terminal 101 receives and inputs a signal from a communication satellite or the like. 102 is an output terminal for transmitting a signal to the VTR
(Data storage device). 103 is an input terminal,
The signal output from the VTR is input. An output terminal 104 is a signal transmitted from a communication satellite or the like, or a VTR.
It outputs signals such as video and audio obtained by decrypting the encryption of the signal input from.

Reference numeral 111 denotes a reception separation circuit, which is an input terminal 101.
A target signal is extracted from the signal input from the signal in which a plurality of programs are multiplexed, and the encrypted main data and the initial value of the key signal necessary for decrypting the main data are separated. An arithmetic circuit 112 receives the initial value of the key signal and generates a key signal by calculation. Reference numeral 113 denotes a memory, in which a code for distinguishing the dedicated IC card from an IC card owned by another user is preset and stored. A management circuit 114 manages and controls the arithmetic circuit 112, the memory 113, and the like.

An encryption circuit 115 encrypts the key signal output from the arithmetic circuit 112 using the identification code stored in the memory 113. 116 is a multiplexing circuit,
The main data output from the reception separation circuit 111 and the encrypted key signal output from the encryption circuit 115 are multiplexed. A separation circuit 117 separates the signal input from the input terminal 103 into main data and an encrypted key signal. Reference numeral 118 denotes a first decryption circuit, which uses the identification code stored in the memory 113 to decrypt the encryption of the key signal output from the separation circuit 117.

Reference numeral 119 denotes a selector, which outputs the main data output from the reception / separation circuit 111 and the main data output from the separation circuit 117 according to the output of the control circuit 122, or outputs from the dedicated IC card 130 in conjunction with each other. The selected key signal and the key signal output from the first decryption circuit 118 are selected and output. A random number generation circuit 120 receives a key signal and generates a pseudo random number. A second decoding circuit 121 decodes the main data output from the selector 119 using the pseudo random number generated by the random number generation circuit 120.
A control circuit 122 controls each unit in the receiving terminal 100. A decompression circuit 123 decompresses a signal compressed at the broadcasting station.

Reference numeral 130 denotes a dedicated IC card supplied from the broadcasting station, and 140 is a data storage device capable of storing digital signals. In this embodiment, the VTR is used as described above. In addition, 150 is an output terminal 104
It is a monitor that displays the video signal and the like output from the.

The request is transmitted and the broadcasting station 201 shown in FIG.
From communication line 212, communication satellite 202, communication line 213
The signal transmitted via the receiving terminal 203 is the receiving terminal 203, that is, FIG.
Receiving terminal 100 mounted with the dedicated IC card 130
Is input to the input terminal 101 of. Although omitted in FIG. 1, in order to receive a radio wave from the communication satellite 202,
For example, an antenna installed indoors or outdoors is required, and a signal received by the antenna is input to the reception separation circuit 111 via the input terminal 101. The reception separation circuit 111 is
First, the received signal is demodulated, and data errors and the like that occur in the communication line in the middle are corrected and complemented. Furthermore, the individual information superimposed on the signal, the initial value of the key signal for decrypting the encryption of the main data, and the encrypted main data are separated and extracted, and the individual information, the initial value of the key signal, etc. Is a dedicated IC card 1
30 and outputs the main data to the multiplexing circuit 116 and the selector 119.

The individual information input to the dedicated IC card 130 is referred to the user ID stored in the memory 113 so that the management circuit 114 can confirm the signal reception permission and the requested program. And extracting the initial value of the key signal for the target program. The initial value of the key signal corresponding to the target program is calculated by the arithmetic circuit 112.
Calculates the key signal based on the initial value of the key signal by performing the calculation with the specific algorithm. This arithmetic circuit 1
As the calculation algorithm in 12, the same algorithm as that for calculating the key signal from the initial value of the key signal in the cipher generation circuit 315 of FIG. 3 is set in advance.

From the broadcasting station, not the encrypted key signal but only the initial value of the encrypted key signal is multiplexed and transmitted, and the encrypted key signal is calculated by the dedicated IC card 130. According to this method, the signal transmitted from the broadcasting station cannot be decrypted by the encryption although the signal can be received by a third party who does not have the dedicated IC card 130. That is, the system prevents unauthorized reception. Furthermore, by making the dedicated IC card 130 removable from the receiving terminal 100 and exchanging the dedicated IC card, it is possible to encrypt the same signal with a different algorithm. In addition, even if the receiving terminal 100 has all the functions such as user ID management on the dedicated IC card side, the receiving terminal can be generalized, and the price can be kept low, and the broadcasting can be further improved. There is an advantage that the management of the receiving terminal is unnecessary on the station side.

The key signal calculated by calculating the initial value in the arithmetic circuit 112 is the encryption circuit 115 and the selector 119.
Is output to In the encryption circuit 115, the user ID output from the management circuit 114 inside the dedicated IC card 130
Is used to encrypt the key signal. Specifically, for example, the user ID is represented by a digital binary code, and an exclusive OR with the input key signal is processed and output. The user ID is assigned to each individual who has a contract with the broadcasting station, and is the same even if the dedicated IC card is replaced.

The key signal encrypted by the encryption circuit 115 is multiplexed with the main data output from the reception / separation circuit 111 in the multiplexing circuit 116 and output from the output terminal 102. The signal output from the output terminal 102 is
By recording in TR140, the received signal can be accumulated / saved.

The signal output from the VTR 140 is input from the input terminal 103 and input to the separation circuit 117. The demultiplexing circuit 117 demultiplexes the encrypted key signal and the main data multiplexed for recording on the VTR 140, and outputs the key signal to the first decryption circuit 118 and the main data to the selector 119, respectively. To be done.

In the first decryption circuit 118, the encryption circuit 1
The key signal encrypted in 15 is decrypted. In this embodiment, the encryption circuit 115 performs encryption by calculating the exclusive OR with the user ID stored in the memory 113. Therefore, this first decoding circuit 1
In 18, the decryption processing of the encrypted key signal is performed by the memory 1
This is performed by recalculating the exclusive OR of the user ID stored in 13 and the input encrypted key signal.

Even when the dedicated IC card 130 is changed while the data is being stored in the VTR 140 and the calculation algorithm is changed, the user ID is the same,
Further, since the signal encrypted by the encryption circuit 115 is a key signal which does not require the operation in the operation circuit 112, the present apparatus does not cause any problem in decrypting the main data. Further, when a duplicate of a received signal recording tape is created by using a plurality of VTRs, if the authorized user makes a duplicate for the purpose of backing up a program received by himself / herself, the dedicated IC card supplied from the broadcasting station is himself / herself. Correct decoding is possible by using. However, if you make a copy for an illegal purpose such as transferring it to a third party, and the third party who receives the transfer of the copy uses a special IC card different from the above, the correct decryption result will be obtained. Can't get Therefore, it is possible to prevent damage to the copyright holder due to illegal copying of the received signal.

The key signal decrypted by the first decryption circuit 118 is input to the selector 119. In the selector 119, the main data output from the reception separation circuit 111 and the separation circuit 1 are output.
One of the main data output from 17 and one of the key signal output from the arithmetic circuit 112 and the key signal output from the first decryption circuit 118 are selected and output according to the instruction of the control circuit 122. To do. That is, the control circuit 12
2, while the reception separation circuit 111 is receiving the signal requested by the user, the selector 119 causes the reception separation circuit 11 to receive the signal.
1 and the key signal output from the arithmetic circuit 112 are selected and output, and the reception separation circuit 11
1 receives no signal and the signal reproduced from the VTR 140 is input from the input terminal 103, the selector 119 keeps the main data output from the separation circuit 117 and the first decoding circuit 118. Select and output the key signal output from.

In the random number generation circuit 120, based on the key signal output from the selector 119, the cipher generation circuit 31 of FIG.
A pseudo random number is generated using the same procedure (or the same table) as in step 5, and the calculation result is output to the second decoding circuit 121.

In the second decoding circuit 121, the selector 119
The main data output from the random number generator 120 is decoded using the pseudo random number output from the random number generation circuit 120, that is, the scramble applied on the broadcast station side is released. For decoding the main data, for example, the pseudo random number generated by the random number generation circuit 120 and the selector 1 are used.
It is performed by calculating the exclusive OR with the main data output from 19, or by decoding the line rotation based on the pseudo random number.

The signal descrambled by the second decoding circuit 121 is decompressed by the decompression circuit 123 by the decompression circuit 123 and subjected to the decompression process and the signal process for outputting to the outside. That is, in the case of a signal compressed by the MPEG method, the signal is expanded by the MPEG decoder, signal processing such as D / A conversion and scanning line conversion is performed, output from the output terminal 104, and displayed on the monitor 150.

As described above, according to the apparatus of this embodiment,
By encrypting the key signal calculated from the initial value of the key signal transmitted from the broadcasting station using the user ID, the scrambled signal can be stored as a backup of the signal received by the user himself. It is possible only when it is intended. Further, the decryption is possible as long as the contract with the broadcasting station is not canceled, that is, as long as the user ID is held. Further, the accumulated signal is a dedicated I stored with the user ID.
Without a C-card, decryption, compression decompression, and projection are impossible, and therefore duplicates cannot be distributed to a third party. That is, the signal can be decoded and stored while preventing the copyright of the signal provider from being infringed.

Further, by providing a memory inside the receiving terminal 100 or by using the memory 113 inside the dedicated IC card 130, the number of times of signal reception and time are stored, and the broadcasting station periodically sends this to the communication line 211 or the like. Find out through,
Alternatively, by collecting and examining the dedicated IC card 130, the receiving terminal 100 or the dedicated IC card 130 can be charged according to the usage status. Furthermore, it becomes possible to easily investigate the signal reception status, for example, the program viewing status.

Next, another embodiment of the present invention will be described with reference to FIG. In the figure, the same components as those of FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted to avoid duplication.

In FIG. 4, 411 is a first selector,
According to a command from the control circuit 122, either the initial value of the key signal output from the reception separation circuit 111 or the initial value of the key signal output from the separation circuit 117 is selected and output. A second selector 412 also selects and outputs one of the main data output from the reception separation circuit 111 or the main data output from the separation circuit 117, in accordance with a command from the control circuit 122.

The receiving / separating circuit 111 demodulates the received signal and corrects a data error generated in a communication line on the way.
After performing signal processing such as complementation, the individual information, the initial value of the key signal for decrypting the encryption of the main data, and the encrypted main data are separated and extracted. And in this embodiment,
The individual information, the initial value of the key signal, etc. are output to the multiplexing circuit 116 and the first selector 411, respectively, and the main data is
It is output to the multiplexing circuit 116 and the second selector 412, respectively. Further, in the multiplexing circuit 116, after the main data and the initial value of the key signal are multiplexed, the data is output from the output terminal 102 and recorded in the VTR 140 to store the signal.
It becomes possible to store.

The signal output from the VTR 140 is input to the demultiplexing circuit 117, the multiplexed signals are demultiplexed by the demultiplexing circuit 116, and the initial value of the key signal is input to the first selector 411 to the main data. Are respectively output to the second selector 412. First selector 411 and second selector 412
Then, according to the same operation as the selector 119 shown in FIG. 1, that is, according to the control circuit 122, while the reception separation circuit 111 is receiving the signal requested by the user, the first selector 411 and the second selector 412 are received. Respectively select and output the initial value of the key signal and the main data output from the reception / separation circuit 111, respectively, and receive no signal in the reception / separation circuit 111, and input the signal reproduced from the VTR 140. While being input from the terminal 103, the first selector 411 and the second selector 412 respectively select and output the initial value of the key signal output from the separation circuit 117 and the main data.

The signal such as the initial value of the key signal output from the first selector 411 is transferred to the dedicated IC card 130.
Similar to the embodiment of FIG. 1, by referring to the individual information with the user ID stored in the memory 113, the management circuit 114 confirms the signal reception permission and the requested program, And the initial value of the key signal for the target program is extracted, and the initial value of the key signal corresponding to the target program is calculated by the arithmetic circuit 112 using a specific algorithm. The key signal is calculated based on the value. As the arithmetic algorithm in the arithmetic circuit 112, the same algorithm as the algorithm for calculating the key signal from the initial value of the key signal in the cipher generation circuit 315 of FIG. Is.

In this dedicated IC card 130, the key signal is calculated after confirming the user ID by referring to the individual information transmitted from the broadcasting station. Therefore, the signal received by itself and the signal received by itself are received. It is possible to calculate the key signal only for the recorded / stored signal, and therefore, it is possible to prevent the disadvantage of the copyright holder due to an illegal copy.

The main data and the key signal calculated by the dedicated IC card 130 are then transferred to the pseudo random number generator 120,
In the decryption circuit 121 and the decompression circuit 123, signal processing such as generation of pseudo-random numbers, decryption of cipher of main data, decompression of compressed signal, etc. is performed in the same manner as in the above embodiment, and the monitor 150 is operated.
Is projected on.

As described above, according to the apparatus of this embodiment, the initial value of the key signal transmitted from the broadcasting station is recorded in the VTR or the like together with the main data, so that the scrambled accumulated signal can be decoded by the user. It is possible only when the user views the signal received by himself. However, when the dedicated IC card of the signal stored by using the device according to the present embodiment is changed, the initial value of the key signal recorded in the VTR is not changed and only the arithmetic algorithm in the arithmetic circuit 112 is changed. However, the correct key signal is not calculated, so that the main data cannot be decrypted. As described above, in the device according to the present embodiment, the period during which the signal can be stored is limited,
In addition, the same effects as those in the above-described embodiment can be obtained by, for example, a viewing situation survey, a charging method, and the like. Further, in the present embodiment, the key signal encryption circuit and the decryption circuit in the receiving terminal are not required, and further, the user ID need not be extracted from the dedicated IC card. There is an advantage that can be reduced.

Here, in each of the above-described embodiments, the communication satellite is taken as an example of the communication line through which the program is transmitted, but other communication lines, for example, a wired communication line using an optical fiber or a coaxial cable. And ISDN (Integrated
It can also be implemented by a telephone line such as Service Digital Network), and the device used as a data storage device is VT.
Not limited to R, a magneto-optical disk device, an optical disk device, a hard disk device, a large capacity memory array or the like may be used.
The signal to be transmitted is not limited to a video signal, but may be a binary coded signal, that is, audio information, character information, game software, etc. if it is a digital signal. Broadcasting station (signal supply side)
The compression method in (2) and the expansion method on the receiving terminal side are not limited to MPEG, and a compression algorithm most suitable for the signal to be transmitted may be used.

Further, the embodiments of FIGS. 1 and 4 are both dedicated ICs.
Although the card is removable, a dedicated IC card is integrated with the receiving terminal, that is, the receiving terminal is a dedicated receiving terminal having an identification code, and functions such as management of individual information and calculation of key signals are provided on the receiving terminal side. It is also possible to have a method of holding it in. In this case, it is necessary to assign a user ID to each receiving terminal and to manage the receiving terminal by the broadcasting station, but it is possible to integrate the control circuits mounted on both the dedicated IC card and the receiving terminal. There are also advantages. It is also conceivable that the receiving terminal and the data storage device are integrated, that is, the VTR or the like also has the function of the receiving terminal. In this case, the same effects as those of the above-described embodiments can be obtained, and the space can be further reduced. Also, the wiring can be simplified.

[0064]

As described above, according to the present invention, it is possible to easily store and store the received binary-coded encrypted data, that is, the encrypted digital signal. Also, if the key signal is encrypted and stored / stored together with the main data, the signal can be stored / stored correctly only when the user himself / herself intends to back up the received signal. is there. Furthermore, the accumulated signal is
That is, those having different user IDs, or user I
Those without D cannot be decrypted. Therefore, it is possible to decode and store the signal while preventing the copyright of the signal supplier from being infringed.

Furthermore, by providing the dedicated IC card with functions such as user ID, management of individual information of signals, and encryption / decryption key signal operation algorithm, which can be attached to and detached from the receiving terminal, the key signal operation algorithm Changes can be made easily and the security of scrambling applied to the signal can be strengthened. Moreover, the main body of the receiving terminal can be generalized by separating it from the dedicated IC card, and the management of the receiving terminal by the broadcasting station side becomes unnecessary. Furthermore, by collecting the dedicated IC card, the user's viewing status can be easily grasped, and as a result, the charge for signal reception can be simplified. User ID
By making the receiving terminal have a dedicated terminal, the control circuit in the terminal can be integrated.

[Brief description of drawings]

FIG. 1 is a block diagram of a receiving terminal (data receiving device) for multi-channel pay digital broadcasting using a communication satellite according to an embodiment of the present invention.

2 is an explanatory diagram showing an example of a configuration of a multi-channel pay digital broadcasting system using a communication satellite including the receiving terminal shown in FIG.

3 is a block diagram showing an example of an internal configuration of a broadcasting station for multi-channel pay digital broadcasting using the communication satellite shown in FIG.

FIG. 4 is a block diagram of a receiving terminal (data receiving device) for multi-channel pay digital broadcasting using a communication satellite according to another embodiment of the present invention.

[Explanation of symbols]

 100 Receiving terminal for pay broadcasting using satellite 101 Input terminal 102 Output terminal 103 Input terminal 104 Output terminal 111 Reception separation circuit 112 Arithmetic circuit 113 Memory 114 Management circuit 115 Encryption circuit 116 Multiplexing circuit 117 Separation circuit 118 First decryption Circuit 119 Selector 120 Random number generation circuit 121 Second decoding circuit 122 Control circuit 123 Decompression circuit 130 Dedicated IC card 140 VTR (data storage device) 150 Monitor 201 Broadcast station 202 Communication satellite 203 Reception terminal 211, 212, 213 Communication line 411 First selector 412 Second selector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Naozumi Sugimura Inventor, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside Video Media Research Laboratory, Hitachi, Ltd. (72) Hiroaki Tachibana 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Hitachi, Ltd. Information & Video Media Division (72) Inventor Hiroyuki Hayakawa 292 Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Information & Media Division, Hitachi, Ltd.

Claims (5)

[Claims] 1. A data receiving device for receiving at least encrypted main data and a digital signal including an initial value of the cipher, wherein the cipher of the main data is decrypted from the received initial value of the cipher. Calculating means for calculating the key signal necessary for the operation, memory means for storing the identification code of the data receiving device, and the key signal calculated by the calculating means using the identification code stored in the memory means. An encryption means for encrypting the received data, a data storage means for storing the received main data and a key signal encrypted by the encryption means, and an encrypted key signal output from the data storage means. Using the identification code stored in the memory means, and the key signal decoded by the first decoding means, the main data output from the data storage means. And a second decryption means for decrypting the data encryption. 2. The data according to claim 1, wherein both the arithmetic means and the memory means are detachable from the data receiving device, and the arithmetic algorithm of the arithmetic means can be changed. Receiver. 3. A data receiving device for receiving at least encrypted main data and a digital signal including an initial value of the cipher, and stores the received initial value of the cipher and the main data. A data storage unit, an arithmetic circuit for calculating a key signal necessary for decrypting the cipher of the main data from the initial value of the cipher output from the data storage unit, and a key signal calculated by the arithmetic circuit. A data receiving apparatus, comprising: a decrypting unit that decrypts the encryption of the main data output from the data accumulating unit. 4. The data receiving apparatus according to claim 3, wherein the arithmetic means is detachable from the data receiving apparatus and the arithmetic algorithm of the arithmetic means can be changed. 5. The data receiving device according to claim 1, wherein the data storage device is a magnetic recording / reproducing device capable of recording / reproducing a digital signal.