JP4246529B2 - Terrestrial digital broadcasting system and terrestrial digital broadcasting rights protection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a terrestrial digital broadcast right protection system, a terrestrial digital broadcast system, and a terrestrial digital broadcast right protection device, for example.
[0002]
[Prior art]
BS digital broadcasting started as a satellite broadcast on December 1, 2000, and free and paid broadcasting services are being operated for viewers. In order for the viewer to receive this BS digital broadcast, an IC card for realizing a CAS (Conditional Access System) function for the receiver is required. This IC card is called a B-CAS card.
[0003]
In the CAS system using the B-CAS card, the broadcast signal is scrambled by an encryption technique, so that the viewers who receive the broadcast signal can be limited.
[0004]
The scramble applied to the CAS method is applied to the video signal and the audio signal. A broadcast signal transmitted from a broadcasting station is composed of a signal scrambled part that is sent by being scrambled, and a part for descrambling the scrambled signal (scramble key Ks) by a receiver. . As described above, when a broadcast signal including a key is transmitted by being scrambled from the broadcast station, a process of restoring the original broadcast signal that can be viewed using the descrambling key is performed in the receiver.
[0005]
The scramble key Ks described above is generally not changed, for example, every few seconds, in order to prevent tampering of the receiver. In order to prevent descrambling, the scramble key Ks and the program information are encrypted together with a common work key Kw. The signal thus encrypted is called an ECM (Entitlement Control Message).
[0006]
In order to restore the contents of the ECM by the receiver, it is necessary to multiplex and transmit the work key Kw to the broadcast signal transmitted from the broadcast station. As for the work key Kw, the contract information between the viewer and the broadcasting station is encrypted and transmitted together. The signal thus encrypted is called an EMM (Entitlement Management Message). This EMM is encrypted with the master key Km. The master key Km is a unique key for each recipient and is stored in the B-CAS card.
[0007]
In this way, it is possible to freely contract the viewing of a desired program provided by each broadcasting station using one B-CAS card. Further, by using this B-CAS card, it is possible to view a pay broadcast program.
[0008]
[Non-Patent Document 1]
The first issue of NIKKEI NEW MEDIA "Digital Broadcasting Guidebook 2001", Nikkei Business Publications, October 30, 2000, pp. 44-57
[0009]
[Problems to be solved by the invention]
As described above, for BS digital broadcasting, the CAS system using a B-CAS card is a system suitable for pay broadcasting. Terrestrial digital terrestrial broadcasting is scheduled to start at the end of 2003, but there are some concerns about applying the B-CAS card.
[0010]
That is, BS digital broadcasting includes pay broadcasting unlike ordinary terrestrial waves. Therefore, the current penetration rate has remained flat, and the number of popularization units, that is, receivers, is limited to the use of millions. Therefore, if millions of viewers receive the reception service, it is easy to manage by the management center.
[0011]
On the other hand, in terrestrial digital broadcasting expected in the future, tens of millions of viewers can be considered even if judging from the number of TVs on the terrestrial broadcast today. The reason for this is that free broadcasts that anyone can freely watch are attractive. Thus, if it is predicted that there are tens of millions of viewers, tens of millions of receivers can be expected to spread.
[0012]
Of course, if the terrestrial digital broadcasting is free broadcasting, it is essential to provide a copyright protection function such as copyright for the receiver, considering that there is no deterioration of data on the receiving side from the transmission form of digital broadcasting. It is.
[0013]
Therefore, in digital terrestrial broadcasting, managing viewers, including the above-mentioned copyright management, is different in scale from the case where millions of viewers receive a reception service, and has a management burden. It is expected to be enormous.
[0014]
Therefore, in order to realize the coming digital terrestrial broadcasting, a method of moving the system using the BS digital broadcasting B-CAS card as it is can be considered. However, in the case of terrestrial digital broadcasting, considering that the number of popularizations will increase dramatically compared to BS digital broadcasting and that it will be free broadcasting that anyone can watch freely, there is no need for hardware in the receiver. There are concerns about an increase in cost burden due to functions and a management burden at the management center.
[0015]
An object of the present invention is to provide a terrestrial digital broadcast system and a terrestrial digital broadcast right protection device capable of realizing a right configuration protection function that is simple and inexpensive in terrestrial digital broadcast.
[0016]
[Means for Solving the Problems]
In order to solve the above-mentioned problems and achieve the above-mentioned purpose, The present invention Is a communication system comprising a transmitter and a receiver for transmitting / receiving content information encrypted with a content key, wherein the transmitter uses content information encrypted with a content key, and the content key is transmitted with a second key. The encrypted first signal, and The first key is the same as the first key stored in the storage unit of the receiver. The first key of at least one unit of lot unit, model unit, or manufacturer unit And generating means for generating a transmission signal by superimposing the second signal encrypted by the transmission means, and transmitting means for transmitting the transmission signal generated by the generation means, wherein the receiver is for the communication system. Lot units, model units, allocated to one or more receivers supplied to And the first key per manufacturer , and Storage means for storing a second key in advance; reception means for receiving a transmission signal transmitted by the transmission means; and the transmission signal received by the reception means stored in the storage means The first key encrypted with the second signal at the transmitter; and And reproducing means for reproducing the content information by decoding according to the second key.
[0017]
The present invention According to the transmitter, the content information encrypted with the content key, the first signal with the content key encrypted with the second key, and The first key is the same as the first key stored in the storage unit of the receiver. The first key of at least one unit of lot unit, model unit, or manufacturer unit A transmission signal is generated by superimposing the second signal encrypted by the transmitter, the generated transmission signal is transmitted, and the receiver is allocated to one or more receivers supplied for the communication system. Units, model units, And the first key per manufacturer , and , Memorize the second key in advance, receive the transmitted signal and send the received signal The first key with the second signal encrypted at the transmitter and Since the content information is reproduced by decrypting according to the second key, it is possible to realize a communication system with a simple configuration and an inexpensive right protection function.
[0018]
Also, The present invention Is the content information encrypted with the content key, the first signal with the content key encrypted with the second key, and The first key is the same as the first key stored in the storage unit of the receiver. The first key of at least one unit of lot unit, model unit, or manufacturer unit Generating means for superimposing the second signal encrypted by the generating means, transmitting means for transmitting the transmission signal generated by the generating means, and for each user who uses the receiver from the receiver When receiving a user key, the receiver comprises: individual transmission means for encrypting service information relating to a service provided in the communication system with the user key and transmitting the information individually to the user. A lot unit, model unit, allocated to one or more receivers supplied for the communication system, And the manufacturer unit The first key, and Storage means for storing the second key and the user key in advance, receiving means for receiving the transmission signal transmitted by the transmitting means, and transmitting signal received by the receiving means in the storage means Remembered said The first key encrypted with the second signal at the transmitter; and Reproducing means for reproducing the content information by decoding according to the second key, and transmitting the user key stored in the storage means to the transmitter and returning it from the transmitter And an individual receiving means for receiving service information.
[0019]
The present invention According to the transmitter, the content information encrypted with the content key, the first signal with the content key encrypted with the second key, and The first key is the same as the first key stored in the storage unit of the receiver. The first key of at least one unit of lot unit, model unit, or manufacturer unit When generating a transmission signal by superimposing the second signal encrypted by the transmission, transmitting the generated transmission signal, and receiving a user key for each user who uses the receiver from the receiver, the receiver receives On the other hand, service information related to services provided in the communication system is encrypted with the user key and transmitted to each user, and the receiver is allocated to one or more receivers supplied for the communication system. Lot unit, model unit, And the manufacturer unit The first key, and , Store the second key and user key in advance, receive the transmitted signal transmitted, The first key with the second signal encrypted at the transmitter and The content information is reproduced by decoding according to the second key, the user key is transmitted to the transmitter, and the user-specific service information returned from the transmitter is received. By implementing a protection function, a service for each individual user can be provided from a transmitter to a receiver in response to a service request.
[0020]
Also, The present invention When the receiver receives the transmission information generated from the content information and the first signal by the generating means, the receiver encrypts the second key stored in the storage unit and the received first signal. The content key is extracted from the first signal and the encrypted content information is decrypted on the condition that the second key has been matched, and the transmitter transmits the second key When updating from the old second key to the new second key, the content key encrypted with the new second key and the old second key are used during the predetermined grace period set as the grace period. An update first signal transmitting means for transmitting a first signal including an encrypted content key to the receiver, and a new second key and an old second key during the grace period Key is encrypted by the first key Update second signal transmission means for transmitting a second signal to the receiver, and the receiver receives the second signal transmitted by the update second signal transmission means, The second signal is decrypted with the first key stored in the storage unit of the receiver, the new second key and the old second key are extracted from the second signal, and stored in the storage unit. A second key comparing means for comparing whether or not the current second key, which is the second key, and the extracted new second key and old second key match, As a result of the comparison by the second key comparison means, only when the match between the current second key and the old second key is confirmed, the current second key is updated to the new second key. And a second key updating means for storing the new second key in the storage unit.
[0021]
The present invention When the receiver receives the transmission signal generated from the content information and the first signal, the receiver encrypts the second key stored in the storage unit and the received first signal. The content key is extracted from the first signal on the condition that the key matches, and the encrypted content information is decrypted. The transmitter uses the second key from the old second key. When updating to the new second key, the content key encrypted with the new second key and the content key encrypted with the old second key during the predetermined grace period set as the grace period A second signal in which the new second key and the old second key are encrypted by the first key during the grace period. Is transmitted to the receiver, and the receiver transmits the transmitted second signal. Upon reception, the second signal is decrypted with the first key stored in the storage unit of the receiver, the new second key and the old second key are extracted from the second signal, and the storage unit stores the new second key and the old second key. The current second key, which is the stored second key, is compared with the new second key and the old second key that have been taken out. Only when a match between the second key and the old second key is confirmed, the current second key is updated to the new second key and the new second key is stored in the storage unit. Therefore, it is possible to make the receiver discriminate between the new and old of the second key, so that the receiver can update the second key to the latest second key.
[0022]
Also, The present invention When notifying each receiver of the update of the second key from the transmitter, unique encryption information predetermined for each user, which is encryption information for encrypting a broadcast signal, Authentication information encrypted by encryption information to be encrypted is mixed in a transmission signal.
[0023]
The present invention According to the above, when the second key update is notified from the transmitter to each receiver, the encryption information that is unique encryption information predetermined for each user and that encrypts the broadcast signal is stored. Since the authentication information encrypted by the encryption information to be encrypted is mixed in the transmission signal, it is possible to confirm the validity of the information received by the right protection LSI.
[0026]
Also, The present invention Is a receiver of a communication system comprising a transmitter and a receiver for transmitting and receiving content information encrypted with a content key, and is allocated to one or more receivers supplied for the communication system Lot unit, model unit, And by manufacturer The first key, and Storage means for storing a second key in advance; content information encrypted with the content key in the transmitter; a first signal with the content key encrypted with the second key; and The first key stored in the storage unit of the receiver One of A reception unit that receives a transmission signal that is generated by superimposing a second signal encrypted by the same first key and transmitted from the transmitter; and a transmission signal that is received by the reception unit Stored in the means First key and And reproducing means for reproducing the content information by decoding according to the second key.
[0027]
The present invention According to the receiver, a lot unit, a model unit, allocated to one or more receivers supplied for the communication system, And by manufacturer The first key, and , The second key is stored in advance, the content information encrypted with the content key in the transmitter, the first signal with the content key encrypted with the second key, and The first key stored in the storage unit of the receiver One of Receive the transmission signal generated and transmitted by superimposing the second signal encrypted with the same first key as the received transmission signal First key and Since the content information is reproduced by decoding according to the second key, it is possible to receive the content information with a simple configuration and an inexpensive right protection function.
[0028]
Also, The present invention Is a receiver of a communication system comprising a transmitter and a receiver for transmitting and receiving content information encrypted with a content key, wherein the transmitter is an individual user who uses the receiver from the receiver. When receiving a key, the service information related to the service provided in the communication system is encrypted with the user key and transmitted to the user individually to the receiver, and the receiver transmits the communication Lot units, model units allocated to one or more receivers supplied for the system, And by manufacturer The first key, and Storage means for storing in advance a second key and a user key for each user who uses the receiver, content information encrypted by the content key in the transmitter, and the content key is the second key. The first signal, encrypted by and The second key is generated by superimposing the second signal encrypted by the same first key as the first key stored in the storage unit of the receiver, and transmitted from the transmitter. A receiving means for receiving a transmission signal; and the transmission signal received by the receiving means is stored in the storage means. One of the first keys and Reproducing means for reproducing the content information by decoding according to the second key, and transmitting the user key stored in the storage means to the transmitter and returning it from the transmitter And an individual receiving means for receiving service information.
[0029]
The present invention When the transmitter receives a user key for each user who uses the receiver from the receiver, the transmitter encrypts service information related to services provided in the communication system to the receiver using the user key. And is transmitted to each user individually. The receiver is a lot unit, a model unit, or a unit allocated to one or more receivers supplied for the communication system. And by manufacturer The first key, and , A second key and a user key for each user who uses the receiver are stored in advance, the content information encrypted with the content key in the transmitter, and the content key encrypted with the second key One signal, and Receiving a transmission signal generated and transmitted by superimposing a second signal encrypted with a first key identical to the first key stored in the storage unit of the receiver. The received transmission signal One of the first keys and The content information is reproduced by decoding according to the second key, the user key is transmitted to the transmitter, and the user-specific service information returned from the transmitter is received. It is possible to realize a protection function and enjoy a service for each individual user in response to a service request.
[0030]
Also, The present invention When the receiver receives the transmission information generated from the content information and the first signal, the receiver encrypts the second key stored in the storage unit and the received first signal. The content key is taken out from the first signal and the encrypted content information is decrypted on the condition that the key matches the second key, and the transmitter transmits the second key to the old second key. When updating from the key to the new second key, the content key encrypted with the new second key and the old second key were encrypted during the predetermined grace period set as the grace period. A first signal including a content key is transmitted to the receiver, and during the grace period, the new second key and the old second key are A second signal encrypted with the key of the receiver, When the receiver receives the second signal transmitted by the transmitter during the grace period, the receiver uses the first key stored in the storage unit of the receiver to receive the second signal. The second signal is decrypted, the new second key and the old second key are extracted from the second signal, the current second key that is the second key stored in the storage unit, and the extracted new key A second key comparing means for comparing whether or not the second key and the old second key match, and a result of the comparison by the second key comparing means, A second key that updates the current second key to the new second key and stores the new second key in the storage unit only when a match with the old second key is confirmed. And updating means.
[0031]
The present invention When the receiver receives the transmission signal generated from the content information and the first signal, the receiver encrypts the second key stored in the storage unit and the received first signal. The content key is extracted from the first signal on the condition that the key matches, and the encrypted content information is decrypted. The transmitter uses the second key from the old second key. When updating to the new second key, the content key encrypted with the new second key and the content key encrypted with the old second key during the predetermined grace period set as the grace period A first signal including the second key and the old second key are encrypted by the first key during the grace period. The second signal transmitted to the receiver, When the receiver receives the second signal transmitted by the transmitter during the grace period, the receiver decrypts the second signal with the first key stored in the storage unit of the receiver, The new second key and the old second key are extracted from the signal, the current second key, which is the second key stored in the storage unit, and the extracted new second key and old second key. Are compared with each other, and if the comparison results in a match between the current second key and the old second key, the current second key is replaced with the new second key. Therefore, the new second key is stored in the storage unit, so that it is possible to distinguish between new and old decryption information and update the latest decryption information.
[0032]
Also, The present invention The second key update means confirms whether the new second key and the old second key match with the current second key by the second key comparison means. In the case where it is not possible, the inability to view due to the absence of decoding information is notified.
[0033]
The present invention According to the above, when the match of the current second key with either the new second key or the old second key is not confirmed, it is informed that viewing is impossible due to the absence of decryption information. It is possible to support confirmation of inability to view by a person.
[0034]
Also, The present invention The transmission by the transmitter is a transmission by a broadcast wave. Also, The present invention The transmission by the transmitter is a transmission by a broadcast wave.
[0035]
The present invention Therefore, since transmission by the transmitter is transmission by broadcast waves, for example, a terrestrial digital broadcasting system can be realized with a simple configuration and an inexpensive right protection function.
[0036]
DETAILED DESCRIPTION OF THE INVENTION
Exemplary embodiments of a digital terrestrial broadcast system and a digital terrestrial broadcast right protection device according to the present invention will be explained below in detail with reference to the accompanying drawings.
[0037]
(Embodiment 1)
First, Embodiment 1 of the present invention will be described from the entire system. FIG. 1 is a diagram showing a digital terrestrial broadcast right protection system according to Embodiment 1 of the present invention.
[0038]
The terrestrial digital broadcasting rights protection system is composed of, for example, a management mechanism 1A, an IDC (Internet Data Center) 2A, an LSI manufacturer 3A, a receiver manufacturer 4A, a broadcasting station 5A, a receiver 6A, etc., as shown in FIG. .
[0039]
The management mechanism 1A controls the entire system by communicating with the IDC 2A. The management mechanism 1A creates an LSI design specification and an LSI public specification, and concludes an NDA (Non Disclosure Agreement) with the LSI manufacturer 3A to provide a private LSI design specification. The management mechanism 1A writes information such as a key to the LSI provided by the LSI manufacturer 3A, and provides the LSI as a right protection LSI to the receiver manufacturer 4A. At that time, the LSI specification (public specification) ) As external specifications.
[0040]
The management mechanism 1A provides information for free broadcasting to the broadcasting station 5A. This information for free broadcasting is information transmitted for each lot number, and includes work key update information and revoke information.
[0041]
The IDC 2A performs master key group management and work key management for free broadcasting, and appropriately provides management information to the management mechanism 1A. The LSI manufacturer 3A receives the LSI design specification from the management mechanism 1A according to the NDA, manufactures the LSI according to the specification, and provides the LSI to the management mechanism 1A.
[0042]
The receiver manufacturer 4A manufactures the receiver according to the LSI specification when the rights protection LSI with the key and the like written therein is provided from the management mechanism 1A. The receiver maker 4A provides the receiver to the viewer, and when a complaint is received from the viewer regarding the defect, the LSI maker 3A requests the LSI manufacturer 3A to replace parts in the case of the defect through the management mechanism 1A. Do.
[0043]
The broadcast station 5A is operated by a broadcaster, and is provided with the above-described work key update information, revoke information, etc. for each lot number from the management mechanism 1A. This broadcasting station 5A has a function of transmitting terrestrial digital broadcasting as free broadcasting. The receiver 6A is a digital terrestrial broadcast receiving device provided to the viewer. The receiver 6A receives broadcast signals such as images and music by terrestrial digital broadcasting, and also receives work key update packets, furnace packets, and the like. The viewer makes an inquiry to the receiver manufacturer 4A about the malfunction of the receiver 6A.
[0044]
Next, the receiver will be described. FIG. 2 is a block diagram showing a configuration example of a receiver according to the first embodiment, FIG. 3 is a diagram for explaining a bit pattern according to the first embodiment, and FIG. 4 is a right protection LSI according to the first embodiment. It is a block diagram which shows roughly the example of 1 structure.
[0045]
As shown in FIG. 2, for example, the receiver 6A includes a tuner 61, a receiver body 62, a right protection LSI 63A, a monitor 64, a speaker 65, and the like.
[0046]
The tuner 61 receives a terrestrial digital broadcast transmission signal captured by an antenna (not shown), demodulates the signal by OFDM (Orthogonal Frequency Division Multiplexing), and outputs the demodulated MPEG-TS packet to the receiver main body 62.
[0047]
The receiver main body 62 extracts an MPEG-TS packet from the input signal by the MPEG-TS packet extraction unit 621, and descrambles the MPEG-TS packet by the scramble key Ks supplied from the processor 622 by the MULTI2 encryption / decryption unit 623. . The receiver main body 62 sends it to the right protection LSI 63A through the processor 622, and receives the scramble key Ks from the right protection LSI 63A through the processor 622.
[0048]
The receiver main body 62 supplies an image signal obtained by decompressing the broadcast signal obtained by descrambling by the MPEG video packet decompression processing unit 624 to the monitor 64, and also obtains the broadcast signal obtained by descrambling. The audio signal obtained by decompressing the MPEG audio packet by the MPEG audio packet decompression processing unit 625 is supplied to the speaker 65.
[0049]
The monitor 64 displays an image based on the image signal supplied from the receiver main body 62. The speaker 65 outputs sound based on the sound signal supplied from the receiver main body 62.
[0050]
The right protection LSI 63A exchanges data with the processor 622 of the receiver main body 62 according to the clock CLK. The rights protection LSI 63A receives information such as an MPEG-TS packet, ECM, EMM, and revoke from the processor 622 of the receiver main body 62, extracts the scramble key Ks, and passes the scramble key Ks to the processor 622 as an encryption / decryption key. The right protection LSI 63A has a secret data input terminal, a number of test terminals, and the like, and inputs a unique number, a master key Km, and an individual key input path from the data input terminal.
[0051]
For example, as shown in FIG. 3, the terrestrial packet (data) is composed of a start bit, 8-bit data, and a parity bit, and continues to the next start bit via a guard interval.
[0052]
For example, as shown in FIG. 4, the right protection LSI 63A includes a packet selector 631A, a Ks encryption / decryption unit 632A, a Kw encryption / decryption unit 633A, a Km encryption / decryption unit 634A, an FRAM (nonvolatile memory) 635A, a ROM 636A, and the like. .
[0053]
According to the above configuration, packets such as ECM, EMM, and revoke are selected from the MPEG-TS packet encrypted by Ks by the packet selection unit 6221A. The packet selection unit 6221A indicates a part that implements the functions of the MPEG-TS packet extraction unit 621 and the processor 622 described above.
[0054]
In the right protection LSI 63A, the FRAM 635A and the ROM 636A are referred to, and the scramble key Ks is extracted. The Km encryption / decryption unit 634A extracts the master key Km (work key number key) from the revoke packet selected by the packet selector 631A, and the Kw encryption / decryption unit 633A works from the master key Km packet selected by the packet selector 631A. The key Kw is taken out. Here, the work key Kw is a KS encryption key and is used for contract unit management.
[0055]
The Ks encryption / decryption unit 632A extracts the scramble key Ks from the work key Kw packet selected by the packet selector 631A. The extracted scramble key Ks is sent to the encrypted MPEG packet decrypting unit 6222A as an encryption / decryption key. Here, the encrypted MPEG packet decoding unit 6222A shows a part that realizes a function corresponding to the MULTI2 encryption / decryption unit 623 and the processor 622, and the decoded MPEG-TS is decompressed in the subsequent stage according to video and audio. Output to processing. The scramble key Ks functions as a content encryption key, and the content format is the MPEG-TS format.
[0056]
In the FRAM 635A, a work key Kw for free broadcasting having a two-stage buffer structure for switching, for example, two spares for switching are prepared, and each master key Km in lot unit, model unit, manufacturer unit, lot number, model Information such as numbers and manufacturer numbers is stored in an updatable manner.
[0057]
The ROM 636A includes an execution instruction, a revocation instruction, a Ks decoding instruction (for free broadcasting), a Kw decoding instruction (for free broadcasting), and the like, and stores a lot number, a manufacturer number, and a model number. .
[0058]
Here, the right protection LSI 63A has a secret input route, and a master key Km, a lot number, a model number, a manufacturer number, and the like can be input by an instruction from the management mechanism and stored in the FRAM 635A.
[0059]
The right protection LSI 63A stores, for example, two lot-unit keys, two model unit keys, and two manufacturer-unit keys as spare master keys Km. As a result, when the key is revoked by revocation, the situation where the digital terrestrial broadcast cannot be received can be dealt with by the spare master key Km.
[0060]
Next, the operation will be described. FIG. 5 is a flowchart for explaining the operation at the time of digital terrestrial broadcasting according to the first embodiment.
[0061]
It is assumed that the management mechanism 1A and the broadcasting station 5A can communicate by either wireless or wired. Transmission for each lot number is performed from the management mechanism 1A to the broadcasting station 5A (step S11). At this time, work key update information, revoke information, and the like are transmitted.
[0062]
When the broadcast station 5A receives work key update information, revoke information, etc. for each lot number (step S21), it superimposes the work key update packet, revoke packet, etc. on the broadcast signal based on the received data. The encrypted transmission signal is output (step S22). Thereby, terrestrial digital broadcasting is performed.
[0063]
In the receiver 6A, when a terrestrial digital broadcast is received (step S31), a work key update, a revoke process, and the like are performed, and a process of outputting the received broadcast to a subsequent monitor or speaker is executed (step S31). S32). In this way, terrestrial digital broadcasting is received under the guarantee of rights protection.
[0064]
As described above, according to the first embodiment, the management mechanism receives the supply of the management protection LSI from the LSI manufacturer, writes information such as a key, and supplies the information to the receiver manufacturer. Since the free terrestrial digital broadcast is received by the viewer's receiver, even if the receiver manufacturer tries to cheat or commercializes a receiver with insufficient rights protection function, it has a simple configuration. It is possible to ensure enforcement of rights by updating the decryption information.
[0065]
In addition, since the management mechanism is notified of the update of the encryption information and the decryption information to the broadcast station, it is possible to ensure enforcement of rights according to the management of the management mechanism.
[0066]
In the management mechanism, at least one of the model unit, lot unit, and manufacturer unit in each receiver is used as the key management unit, so that the management operation cost can be greatly reduced.
[0067]
Also, in the broadcasting station, when at least one unit among the model unit, the lot unit, and the manufacturer unit is notified from the receiver, the work key Kw (decryption information) of each receiver is updated in the received unit. Since this is implemented, it is possible to efficiently update the decryption information by at least one unit among the model unit, the lot unit, and the manufacturer unit.
[0068]
In addition, the rights protection LSI function scramble key Ks for scrambling / descrambling the broadcast signal, the work key Kw for encrypting / decrypting the Ks and the scrambled broadcast signal together, and the Kw encrypted Since the broadcast signal is limited to encryption / decryption by the master key Km for encrypting / decrypting the broadcast signal and the revocation function, the cost of the right protection function can be minimized.
[0069]
(Embodiment 2)
In the first embodiment described above, the management mechanism writes a key or the like to the management protection LSI supplied from the LSI manufacturer. However, the present invention is not limited to this, and the following is described. As described in the second embodiment, the LSI manufacturer may write a key or the like in the management protection LSI. Only the parts different from the first embodiment will be described below, and the description of the common parts and the description of the effects will be omitted.
[0070]
An example is shown in FIG. FIG. 6 is a diagram showing a terrestrial digital broadcast right protection system according to Embodiment 2 of the present invention.
[0071]
The actual digital terrestrial broadcasting rights protection system according to the second embodiment is configured by a management mechanism 1B, IDC 2B, LSI manufacturer 3B, receiver manufacturer 4B, broadcasting station 5B, receiver 6B, etc., as shown in FIG. 6, for example. . Here, since the right protection LSI provided in the receiver 6B has the same configuration and function as the right protection LSI 63A (see FIG. 4) of the first embodiment described above, description thereof is omitted.
[0072]
In the configuration of FIG. 6, the difference from the above-described first embodiment is that information such as a key is provided from the management mechanism 1B to the LSI manufacturer 3B, and the information such as the key is written into the LSI in the LSI manufacturer 3B. is there. Accordingly, the right protection LSI is provided directly from the LSI manufacturer 3B to the receiver manufacturer 4B. As described above, in the second embodiment, the information provided from the management mechanism 1B to the receiver manufacturer 4B is an LSI specification that is an external specification.
[0073]
As described above, according to the second embodiment, the management mechanism communicates only the key information to the LSI manufacturer, and the LSI manufacturer writes the key or the like to the management protection LSI. Since the exchange of problems between the receiver maker and the LSI maker is performed, the amount of work of the management mechanism is reduced, and even if the receiver maker tries to cheat or the receiver has insufficient rights protection function. Even after commercialization, it is possible to ensure enforcement of rights by updating decryption information with a simple configuration.
[0074]
(Embodiment 3)
In the first and second embodiments, the update information of the work key Kw is periodically transmitted from the broadcasting station or the revoke command is transmitted. However, the present invention is not limited to this, As in the third embodiment described below, the broadcasting station may perform services such as updating the work key Kw in response to a request from the user, that is, the viewer. Hereinafter, parts different from those of the first and second embodiments will be described with emphasis, and description of common parts and detailed description of the effects thereof will be omitted.
[0075]
One example is shown in FIG. 7, which is a diagram showing a terrestrial digital broadcast right protection system according to Embodiment 3 of the present invention. The digital terrestrial broadcast right protection system shown in FIG. 7 is applied based on the configuration of the second embodiment (see FIG. 6) described above.
[0076]
The actual digital terrestrial broadcasting rights protection system according to the third embodiment includes a management mechanism 1C, IDC 2C, LSI manufacturer 3C, receiver manufacturer 4C, broadcasting station 5C, receiver 6C, etc., as shown in FIG. 7, for example. .
[0077]
In the configuration of FIG. 7, the difference from the above-described second embodiment is that the receiver 6C operated by the viewer communicates the viewer complaint with the identification information such as the user's telephone number to the broadcasting station 5C, This is in that Kw individual transmission is performed from the broadcasting station 5C to the receiver 6C using a user key for each user. As a result, the receiver 6C receives Kw individual transmission and enjoys a service such as updating the work key Kw based on the user key. Further, the IDC 2C is different in that it manages a user number for identifying a user and a correspondence table between the user number and the user key as information for free broadcasting.
[0078]
Next, the right protection LSI will be described. FIG. 8 is a block diagram schematically showing a configuration example of the right protection LSI according to the third embodiment.
[0079]
For example, as shown in FIG. 8, the right protection LSI 63C includes a packet selector 631C, a Ks encryption / decryption unit 632C, a Kw encryption / decryption unit 633C, a Km encryption / decryption unit 634C, an FRAM 635C, and a ROM 636C. Note that the packet selection unit 6221C and the encrypted MPEG packet decryption unit 6222C are the same as those in Embodiments 1 and 2 described above as functions on the receiver side, and thus description thereof is omitted.
[0080]
This right protection LSI 63C has the same configuration and function as the right protection LSI of the first and second embodiments described above. The difference from the first and second embodiments is that the user individual key is stored in the FRAM 635C. There is in point. With this user individual key, Kw individual transmission sent from the broadcasting station 5C can be decrypted for each user.
[0081]
Next, the operation will be described. FIG. 9 is a flowchart for explaining the operation during digital terrestrial broadcasting according to the third embodiment. Since the entire operation related to digital broadcasting is the same as that of the first and second embodiments, the viewer complaint that is the difference from the first and second embodiments and the Kw individual transmission corresponding thereto are described here. explain.
[0082]
First, in the receiver 6C, a viewer complaint including a user number for identifying each user is transmitted to the broadcasting station 5C by the operation of the viewer (step S51). Correspondingly, in the broadcasting station 5C, when the viewer complaint is received (step S41), the user number is extracted from the transmission data of the viewer complaint, and the management mechanism 1C is inquired about the user number. Is performed (step S42).
[0083]
Thereby, a user's confirmation is performed. At that time, in the management mechanism 1C, the user number is notified to the IDC 2C, and the user key corresponding to the user number is supplied. In this way, the user key is sent from the management mechanism 1C to the broadcasting station 5C.
[0084]
In the broadcasting station 5C, when the user key is obtained, Kw individual transmission encrypted based on the user key is executed (step S43). This Kw individual transmission includes services such as Kw update corresponding to the user number.
[0085]
Then, when the Kw individual transmission is received, the receiver 6C performs decryption based on the user key (step S52), and enjoys services such as Kw update (step S53).
[0086]
As described above, according to the third embodiment, a simple configuration and an inexpensive right protection function are realized, and the broadcast station responds to a service request from the viewer through the receiver for each individual user. It is possible to provide services.
[0087]
(Embodiment 4)
In the first, second, and third embodiments described above, an example on the premise of free broadcasting is shown. However, the present invention is not limited to this, and the fourth embodiment described below is used. In addition, it may be applied to pay broadcasting. In the following, based on the system of the above-described second embodiment, the additional part will be emphasized and described, and the description of the common part and the detailed description of the effect will be omitted.
[0088]
An example is shown in FIG. FIG. 10 is a diagram showing a digital terrestrial broadcast right protection system according to Embodiment 4 of the present invention. The terrestrial digital broadcast right protection system shown in FIG. 10 is applied based on the configuration of the second embodiment (see FIG. 6) described above.
[0089]
The actual digital terrestrial broadcasting rights protection system according to the fourth embodiment includes a management mechanism 1D, IDC 2D, LSI manufacturer 3D, receiver manufacturer 4D, broadcasting station 5D, receiver 6D, IDC 7D, and the like as shown in FIG. Is done.
[0090]
In the configuration of FIG. 10, the difference from the above-described first to third embodiments is that a configuration for newly supporting pay broadcasting is provided. That is, the management information of the pay broadcast is managed by the IDC 7D, and information is appropriately exchanged between the IDC 2D and the IDC 7D regarding the management of the pay broadcast. In the IDC 7D, at least pay broadcast Kw, contract information, and billing information are managed as pay broadcast (PPC: Pay per Channel) management information.
[0091]
In IDC2D, a table in which user numbers and user numbers and user keys are associated with each other is managed for pay broadcasting. This user number and user key are exchanged with the management mechanism 1D. The broadcasting station 5D is provided with a PPC management mechanism that communicates with the IDC 7D and manages pay broadcasting.
[0092]
In the configuration of FIG. 10, the difference between the third embodiment and the user number usage mode is that the receiver 6D operated by the viewer applies to the broadcast station 5D for the application for pay broadcast identification information such as the telephone number of the user. The broadcast station 5D transmits to the receiver 6D the pay broadcast activation for the PPC-Kw update, the pay broadcast message, and the contract information update based on the pay broadcast using the user key for each user. There is in point to do.
[0093]
As a result, the receiver 6D receives the pay broadcast activation transmission and enjoys services such as PPC-Kw update, pay broadcast message, and contract information update based on the user key. At this time, the management mechanism 1D is responsible for obtaining a user key corresponding to the user number from the IDC 2D in response to a user key inquiry based on the user number from the broadcast station 5D and passing it to the broadcast station 5D.
[0094]
Next, the right protection LSI will be described. FIG. 11 is a block diagram schematically showing a configuration example of a right protection LSI according to the fourth embodiment.
[0095]
For example, as shown in FIG. 11, the right protection LSI 63D includes a packet selector 631D, a Ks encryption / decryption unit 632D, a Kw encryption / decryption unit 633D, a Km encryption / decryption unit 634D, an FRAM 635D, and a ROM 636D. Note that the packet selection unit 6221D and the encrypted MPEG packet decryption unit 6222D are the same as those in the first to third embodiments as functions on the receiver side, and thus description thereof is omitted.
[0096]
This right protection LSI 63D has the same configuration and function as the base part of the right protection LSI of the first to third embodiments. Regarding the difference from the above-described first to third embodiments, the FRAM 635D stores Km as an individual key for each user in association with pay broadcasting, and further obtains PPC-Kw (for pay channel use) by applying for pay broadcasting. Kw), pay channel message, and pay channel contract information are stored in predetermined areas. Note that the user number is acquired by, for example, a secret input route and stored in the FRAM 635D.
[0097]
There is also a difference for ROM 636D. The ROM 636D further stores an individual number presentation instruction, a pay channel message presentation instruction, a pay broadcast Kw decoding instruction, a pay broadcast contract information storage instruction, and a pay broadcast contract information presentation instruction.
[0098]
The individual number presentation command is a command for presenting a user number, and the pay channel message presentation command is a command for presenting a message. The pay broadcast Kw decryption command is a command for performing Kw decryption for pay broadcast, and is related to the Kw encryption / decryption 633D. The pay broadcast contract information storage command and the pay broadcast contract information presentation command are commands for storing and presenting the FRAM 635Deno of the contract information, respectively.
[0099]
Next, the operation will be described. FIG. 12 is a flowchart for explaining the operation at the time of digital terrestrial broadcasting according to the fourth embodiment.
[0100]
In order for a viewer (user) to watch a pay broadcast for a terrestrial digital broadcast, the viewer himself / herself must apply for the pay broadcast. Accordingly, when a pay broadcast application is made from the receiver 6D to the broadcast station 5D by the operation of the viewer (step S81), the broadcast station 5D accepts the application, and the management mechanism 1D receives the user key. An inquiry is made (step S71). The above-mentioned pay broadcast application may be made with a user number via a telephone line, an Internet line, or a VPN line.
[0101]
In the management mechanism 1D, a process of receiving a user key from the IDC 2D in response to an inquiry from the broadcasting station 5D and returning the user key with the user key is executed (step S61). When the user key is sent to the broadcasting station 5D (step S72), transmission is performed by encrypting the transmission data based on the user key to the receiver 6D as the application source (step S73). The transmission signal to the receiver 6D includes PPC-Kw update information, a pay broadcast message, and contract information.
[0102]
In the receiver 6D, when a transmission signal from the broadcasting station 5D is received, decryption based on the user key is performed (step S82), and the contents of the FRAM 635D are updated as shown in FIG. 11 (step S83). . Then, when pay terrestrial digital broadcasting is performed from the broadcasting station 5D (step S74), it is possible to receive only the contracted pay channel (step S84). In this way, the viewer can view a desired pay channel.
[0103]
As described above, according to the fourth embodiment, when an application for pay broadcasting is made from a viewer through a receiver to a broadcasting station, the management mechanism decrypts the paying broadcast for the receiving receiver. Since the information is passed through and the decoding information of the receiver is updated, the pay broadcast can be enabled by the pay broadcast required management mechanism, and the pay broadcast can be managed by the pay broadcast management mechanism. is there.
[0104]
(Embodiment 5)
In the system of the fourth embodiment described above, additional registration of pay broadcast channels may be performed as in the fifth embodiment described below. In the fifth embodiment described below, the description of the configuration and effects common to the above-described fourth embodiment is omitted.
[0105]
An example is shown in FIG. FIG. 13 is a block diagram schematically showing a configuration example of the right protection LSI according to the fifth embodiment.
[0106]
For example, as shown in FIG. 13, the right protection LSI 63E includes a packet selector 631E, a Ks encryption / decryption unit 632E, a Kw encryption / decryption unit 633E, a Km encryption / decryption unit 634E, a FRAM 6351E, a FRAM 6352E, a FRAM 6354E, a FRAM 6354E, and a ROM 636E. . The packet selection unit 6221E and the encrypted MPEG packet decryption unit 6222E are the same as those in the first to third embodiments as functions on the receiver side, and thus the description thereof is omitted.
[0107]
This right protection LSI 63E has the same configuration and function as the base part of the right protection LSI of the first to third embodiments. The difference from the first to third embodiments described above is that FRAM 6351E stores Km as an individual key for each user in relation to pay broadcasting.
[0108]
The FRAM 6352E stores PPC-Kw (paid channel Kw), pay channel message, and pay channel contract information acquired by pay broadcast application in predetermined areas, and the FRAM 6353E and 6354E have the same use as the FRAM 6352E. There is a difference in that it is used in correspondence with other paid channels. Note that the user number is acquired by, for example, a secret input route and stored in the FRAM 635D.
[0109]
Here, the FRAM 6354E is a pay channel area n (n is a natural number). However, if it is an optimal number as a right protection LSI, it may be provided in advance.
[0110]
There is also a difference for ROM 636E. In the ROM 636E, for example, a program for confirming the free space of the FRAM is provided for the configuration of the ROM 636C in FIG. In this free space determination step, if there is a free space, the pay channel is additionally registered in the FRAM, and if there is no free space, a message indicating that the pay channel cannot be registered is output or a new one is added to the existing pay channel (old pay channel). Control is performed to overwrite the pay channel (new pay channel). The viewer may arbitrarily select the control for no space.
[0111]
Next, the operation will be described. FIG. 14 is a flowchart for explaining the operation at the time of digital terrestrial broadcasting according to the fifth embodiment. Only paid channel registration will be described here. Since the fourth embodiment is the same as the application for pay broadcasting, the same steps as those in FIG. 12 are denoted by the same reference numerals and the description thereof is omitted.
[0112]
Also in the receiver of the fifth embodiment, the user key is obtained by applying for pay broadcasting to the broadcasting station (steps S81 and S82). Then, when information on the pay channel is stored in the FRAM, first, the capacity is checked to see if there is a free area (step S91).
[0113]
At this time, if there is an empty area (YES route in step S91), the FRAM is updated by additional registration of the hot water channel (step S92), and thereafter, the pay broadcast is received by the receiver including the additionally registered pay channel. (Step S84).
[0114]
On the other hand, if there is no free space (NO route in step S91), an inquiry is made to the viewer as to whether or not to overwrite the new pay channel (step S93). In this case, a message may be displayed on a display (not shown) of the receiver.
[0115]
When overwriting is accepted by the viewer's operation (YES route in step S93), a process of overwriting the new pay channel on the existing pay channel is executed (step S94). The pay broadcast can be received by the receiver including the additionally registered pay channel (step S84).
[0116]
On the other hand, when the overwrite is not accepted by the operation of the viewer (NO route of step S93), the pay broadcast can be received by the receiver while the existing pay channel is kept as it is (step S84). .
[0117]
As described above, according to the fifth embodiment, in the right protection LSI, the update for validating the pay broadcast is performed on the FRAM (nonvolatile memory), and the area for performing the update is set. If it cannot be secured, the old pay channel (old information about pay broadcast) is deleted or the new pay channel (new information about pay broadcast) is overwritten by the operation of the viewer, so that it is stored on the FRAM of the rights protection LSI. It is possible to add a new paid channel while there is free space. In addition, if an area for updating cannot be secured, it is possible to arbitrarily perform whether or not the pay channel is overwritten from old to new by the operation of the viewer.
[0118]
In the fifth embodiment described above, it is determined whether or not the new pay channel is overwritten when there is no free space at the time of application for pay broadcasting. However, the present invention is not limited to this, and a free space is available in advance. A rule for when there is no capacity may be determined.
[0119]
(Embodiment 6)
In the receivers of the first to fifth embodiments described above, no specific example has been shown in the update of the work key Kw. However, as in the sixth embodiment described below, the old work key Kw and the new work key are not shown. The key Kw may be mixed to perform an update process for matching the current work key Kw on the receiver side with the new work key. In the sixth embodiment described below, the deformed portion can be applied to any of the first to fifth embodiments described above, and descriptions of common configurations and effects are omitted.
[0120]
First, the principle will be described with reference to FIG. FIG. 15 is a diagram for explaining an example of a packet at the time of digital terrestrial broadcasting according to the sixth embodiment.
[0121]
A transmission signal from the broadcasting station is transmitted by an MPEG packet as shown in FIG. In this MPEG packet, Kw update (for example, composed of 188 bytes), compressed video, and compressed audio are stored. An MPEG packet for Kw update, that is, a Kw update packet, is preferably composed of a packet ID, an updated new Kw, a new Kw corresponding number, and other information.
[0122]
However, when the Kw update passes a certain period (update grace period) and the transmission of the scramble key Ks corresponding to the old work key Kw is cancelled, which stage of the work key Kw is registered in the right protection LSI. It is necessary to confirm whether it is done.
[0123]
Therefore, in the sixth embodiment, as shown in FIG. 15B, the combination of the new Kw and the new Kw correspondence number and the combination of the old Kw and the old Kw correspondence number are mixed in the Kw update packet. In addition, a function for informing the right protection LSI of what the old and new Kw is is added. For this purpose, the right protection LSI is provided with a function for distinguishing the new work key Kw and the old work key Kw.
[0124]
Next, the right protection LSI will be described. FIG. 16 is a block diagram schematically showing a configuration example of a right protection LSI according to the sixth embodiment.
[0125]
For example, as shown in FIG. 16, the right protection LSI 63F according to the sixth embodiment has a mechanism in which a function realized by hardware and a function realized by software coexist. In FIG. 16, the function expressed by a practical block indicates a hardware implementation function, and the function expressed by a dotted line block indicates a software implementation function.
[0126]
For example, as shown in FIG. 16, the right protection LSI 63F includes a packet selection unit 6221F, a processor 631F, FRAM 632F, hardware by the encryption / decryption units 633F, 635F, update by the Kw update packet, registration number 634F, and number by the Ks packet. It is configured by software processing by confirmation and Ks decoding processing 636F.
[0127]
In the above configuration, packet selection is performed by the packet selection unit 6221F. In the case of a Kw update packet, the encryption / decryption unit 633F decrypts the selection packet using the master key Km, and in the case of the Ks update packet, the encryption / decryption unit 635F decrypts the selection packet using the work key Kw. .
[0128]
In the case of the Kw update packet, the processor 631F updates the Kw and registers the Kw number for the FRAM 632F. In the case of a Ks packet, the Kw number is confirmed, Kw corresponding to the number is selected, and the selected Kw is supplied to the encryption / decryption unit 635F.
[0129]
Specifically, the new / old work key Kw is acquired from the Kw update packet by the encryption / decryption unit 633F. When the work key Kw that matches the old work key Kw is used as the current key among the old and new work keys Kw, the FRAM 632F is updated to the new work key Kw (Kw update and its number registration, etc.) Is done.
[0130]
In the encryption / decryption unit 635F, Ks is decrypted based on the selected Kw except when Kw is updated. In this way, the scramble key Ks for descrambling the scrambled broadcast signal is output. In addition, when Kw update is completed, it is possible to receive terrestrial digital broadcasts using the new Kw, and if Kw update is impossible, processing such as notifying the viewer of the absence of Kw is executed. Is done.
[0131]
In the sixth embodiment, a packet in which up to one old Kw before the new Kw is mixed is transmitted, but two or more previous Kw may be mixed. .
[0132]
To distinguish between the new work key Kw and the old work key Kw, the new Kw identification information and the old Kw identification information may be inserted into the Kw update packet. In this case, the right protection LSI can identify the new Kw or the old Kw from the identification information inserted in the Kw update packet.
[0133]
Next, the operation will be described. FIG. 17 is a flowchart for explaining the operation at the time of digital terrestrial broadcasting according to the sixth embodiment.
[0134]
At the time of Kw update, in the MPEG packet transmission, a Kw update packet is transmitted from the broadcast station as shown in FIG. 15B (step S101). In the receiver, the MPEG packet transmitted from the broadcast station is received (step S111), and the current work key Kw currently stored in the FRAM is compared with the old and new work keys Kw in the received packet (step S111). S112).
[0135]
If a match with the old work key Kw is confirmed (YES route in step S113), the current work key Kw is updated to the new work key Kw, and the match with the new work key Kw is confirmed. If it has been done (YES route of step S113), the process is terminated as being updated (step S114).
[0136]
On the other hand, if no match is found between the new and old work keys (NO route of step S113), a message indicating the absence of Kw is output to a display (not shown) of the receiver (step S115).
[0137]
As described above, according to the sixth embodiment, when a receiver receives a broadcast signal obtained by multiplexing old and new work keys Kw transmitted from a broadcasting station, the current work key Kw and the broadcasting station The old work key Kw and the new work key Kw that have been sent are collated and the new work key Kw is updated according to the match of the old work key Kw. The work key Kw can be updated.
[0138]
When updating Kw, it is impossible to update Kw for all viewers at the same time due to different circumstances (such as reception environment) for each viewer. If there is a receiver that has not been able to update Kw, a viewer using the receiver may not be able to view. Therefore, as in the sixth embodiment, by mixing the old Kw in the Kw update packet, it is possible to receive the terrestrial digital broadcast with the old Kw even if the receiver has not been updated with Kw. . Therefore, if either the old or new Kw is registered, terrestrial digital broadcasting can be received.
[0139]
In addition, when a certain period (update grace period) passes from the broadcasting station, the transmission of the scramble key Ks corresponding to the old work key Kw is stopped, so that the match of the old work key Kw cannot be confirmed by the above-described collation. Is able to notify an unillustrated display or the like by a message or the like when the work key is absent. As a result, it is possible to assist the viewer in confirming that viewing is impossible.
[0140]
(Embodiment 7)
In the first to sixth embodiments described above, the work key Kw is updated by a transmission signal, that is, a broadcast wave packet. However, the present invention is not limited to this, and a telephone line or an Internet line is used. In this case, the update information may be assured as in the seventh embodiment described below. The seventh embodiment described below can be applied to any of the first to sixth embodiments described above, and a description of common configurations and effects will be omitted.
[0141]
The principle is shown in FIG. FIG. 18 is a diagram for explaining an example of a packet at the time of digital terrestrial broadcasting according to the seventh embodiment.
[0142]
A transmission signal from the broadcasting station is transmitted by an MPEG packet as shown in FIG. In this MPEG packet, Kw update (for example, composed of 188 bytes), compressed video, and compressed audio are stored. An MPEG packet for Kw update, that is, a Kw update packet, is preferably composed of a packet ID, an updated new Kw, a new Kw corresponding number, and authentication information according to the seventh embodiment.
[0143]
In the Kw update packet, the new Kw, the new Kw correspondence number, and the authentication information are encrypted with the master key. Therefore, the safety of the MPEG packet can be confirmed by decrypting the contents. A tag value is set for each of the new Kw, the new Kw correspondence number, and the authentication information, and it is possible to confirm whether the new Kw, the new Kw correspondence number, or the authentication information from the tag value. In FIG. 18, as an example, tag values A and B are shown for new Kw and authentication information, respectively.
[0144]
By assigning tag values in this way, the order in which the new Kw, new Kw corresponding number, and authentication information are arranged in the Kw update packet need not be the same. As a result, illegal decoding of MPEG packets can be made difficult.
[0145]
Next, the operation will be described. FIG. 19 is a flowchart for explaining the operation at the time of digital terrestrial broadcasting according to the seventh embodiment.
[0146]
A Kw update packet including authentication information is transmitted from the broadcasting station as shown in FIG. 18 (step S121). In the receiver, when a packet is received (step S132), the decoding is performed (step S133). At the time of this decryption, the tag value shown in FIG. 18 is referred to and it is determined whether it is new Kw or authentication information.
[0147]
Then, authentication is performed based on the decrypted authentication information (step S133). If the authentication is successful (YES route in step S133), the Kw update to the new work key Kw is performed (step S134). If the authentication is not successful, the Kw update is not executed.
[0148]
As described above, according to the seventh embodiment, when update of decryption information is notified from a broadcast station to a receiver, a master key Km (unique encryption information predetermined for each user) is determined. Since the authentication information encrypted in (2) is mixed in the transmission signal, it is possible to confirm the validity of the information received by the right protection LSI.
[0149]
(Embodiment 8)
In the first to seventh embodiments described above, a specific example of revocation information is not shown, but a revocation packet is exchanged between a broadcasting station and a receiver as in the eighth embodiment described below. It may be. Embodiment 8 described below is applicable to any of Embodiments 1 to 7 described above, and a description of common configurations and effects is omitted.
[0150]
First, the revoke function will be described. The revoke function is executed by a revoke command. The revoke command is transmitted, for example, in the payload of an MPEG2-TS packet. A revoke command is executed for each manufacturer key, model key, and lot key. It is possible to designate whether to invalidate the work key Kw by the revocation instruction, and it is possible to invalidate the current key and validate the alternative key at the same time.
[0151]
Therefore, it is possible to continue receiving the substitute key even at the revoke receiver. Thereby, it is possible to deal with the leakage of the work key Kw and the current key. Note that the substitute key is stored in the FRAM of the right protection LSI. When n (n is a natural number) alternative keys are stored, it is possible to handle up to n revocations.
[0152]
Further, in order to maintain safety such as prevention of leakage of revoke commands, a master key dedicated to revoke may be prepared. In this case, the revoke command is encrypted with the revoke dedicated key, and further transmitted after being encrypted with the manufacturer key, model key, and lot key.
[0153]
Next, the principle of the eighth embodiment is shown in FIG. 20 and FIG. 20 is a diagram for explaining revoke transmission according to the eighth embodiment, and FIG. 21 is a diagram for explaining ECM transmission according to the eighth embodiment.
[0154]
The revoke packet (MPEG-TS format) includes, for example, a header part, a packet ID, a manufacturer number, a model number, a lot number, an individual number part, decryption key selection information, an encrypted revoke as shown in FIG. It consists of parts such as an instruction, time information, and error correction information.
[0155]
In the rights protection LSI, a process of decrypting a revoke command encrypted from one or a part of the manufacturer number (Km), model number (Km), and individual number (Km) from the decryption key selection information is executed. Is done. Then, after the first decryption is performed, this time, the second decryption is performed for extracting time information and the like based on the revoke key.
[0156]
In the right protection LSI, the duration of power-on is stored as time information 1 in the FRAM by a timer, for example, every 5 minutes. The time information 2 obtained in this way is compared with the time information 1 stored in the right protection LSI. If the time interval is equal to or greater than a certain range, it is determined that the Kw has not been updated within a certain time by the revoke command. Invalidation of Kw is executed.
[0157]
Further, as shown in FIG. 21, the ECM packet may be configured to transmit the encrypted time information simultaneously with the encryption Ks. The ECM packet is composed of a header, manufacturer, model, lot, individual number, encrypted Ks key, and encrypted time information. The encrypted time information includes encrypted time information falsification detection information. This encrypted time information falsification detection information is, for example, a checksum.
[0158]
In packet selection, packet selection is performed based on the packet ID or the like in the header. In ECM selection, ECM is selected based on the manufacturer number, model number, lot number, individual number, and the like. As a result, when the encrypted Ks is extracted, Ks is decrypted with the work key Kw.
[0159]
When the encrypted time information is extracted, the time information is decrypted with the work key Kw. Further, when the encrypted information falsification detection information is extracted, the falsification detection information is decrypted with the work key Kw.
[0160]
A checksum operation is performed on the decoding time information thus obtained, and the checksum obtained as a result is compared with the checksum indicated by the falsification detection information. As a result, when the match is confirmed, the legitimacy of the decryption Ks is ensured without falsification. On the other hand, when the mismatch is confirmed, fraud of the ECM packet is confirmed with falsification.
[0161]
As described above, according to the eighth embodiment, in the right protection LSI, the time information inserted in the transmission signal at the broadcasting station is referred to, and the predetermined decryption information is updated within a certain continuous time. If not, the predetermined decryption information is invalidated, so that it is possible to ensure the security of the right protection LSI and to update the decryption information within a predetermined time.
[0162]
In the right protection LSI, the time information encrypted by the broadcasting station is decrypted based on the decryption information, so that it is possible to prevent the time information from being falsified.
[0163]
(Modification 1 common to Embodiments 1 to 8)
In the first to eighth embodiments described above, the management mechanism and the broadcasting station are communicably connected to each other using the Internet line, and the encryption information and the decryption information are updated from the management mechanism to the broadcasting station. Notification may be performed via the Internet line.
[0164]
An example is shown in FIG. FIG. 22 is a block diagram for explaining an example of the network of the terrestrial digital broadcasting system of the present invention. In the first modification, the broadcast station 9 and the receiver 6 are connected by the Internet line 7 as shown in FIG.
[0165]
In this way, it is possible to greatly reduce the communication cost.
[0166]
(Modification 2 common to Embodiments 1 to 8)
In the first modification described above, the Internet line is used. However, the present invention is not limited to this, and the management mechanism and the broadcasting station are connected to each other via a VPN line so as to be communicable, and the management mechanism transmits the broadcasting station. The encryption information and decryption information may be updated and a revocation request may be notified via the VPN line.
[0167]
An example is shown in FIG. FIG. 23 is a block diagram for explaining another example of the network of the terrestrial digital broadcasting system of the present invention. In the second modification, the broadcasting station 9 and the receiver 6 are connected by the VPN line 8 as shown in FIG.
[0168]
In this way, communication is dedicated through the VPN line, and thus the communication line can be secured.
[0169]
The present invention is not limited to the above-described embodiments and modifications, and various modifications can be made without departing from the spirit of the present invention.
[0170]
(Appendix 1) A terrestrial digital broadcasting system that performs digital broadcasting between a broadcasting station and one or more receivers using terrestrial waves,
The broadcasting station
Generating means for generating a transmission signal by superimposing encryption information for rights protection and an encrypted broadcast signal;
Transmitting means for transmitting the transmission signal generated by the generating means using terrestrial waves;
With
The receiver
Storage means for previously storing decryption information for decrypting a transmission signal allocated and encrypted in predetermined units to one or more receivers supplied for the terrestrial digital broadcasting system; ,
Receiving means for receiving a transmission signal transmitted by the transmitting means;
Reproducing means for reproducing the broadcast signal by decoding the transmission signal received by the receiving means according to the decoding information stored in the storage means;
A terrestrial digital broadcasting system characterized by comprising:
[0171]
(Appendix 2) A terrestrial digital broadcasting system that performs digital broadcasting between a broadcasting station and one or more receivers using terrestrial waves,
The broadcasting station
Generating means for generating a transmission signal by superimposing encryption information for rights protection and an encrypted broadcast signal;
Transmitting means for transmitting the transmission signal generated by the generating means using terrestrial waves;
Individual transmission means for transmitting service information for each user to the receiver when receiving user-specific cryptographic information from the receiver;
With
The receiver
Decoding information and user-specific encryption information for decrypting a transmission signal that is allocated and encrypted in predetermined units to one or more receivers supplied for the terrestrial digital broadcasting system is stored in advance. Storage means,
Receiving means for receiving a transmission signal transmitted by the transmitting means;
Reproducing means for reproducing the broadcast signal by decoding the transmission signal received by the receiving means according to the decoding information stored in the storage means;
Individual receiving means for receiving user-specific service information returned from the broadcasting station by transmitting user-specific encryption information stored in the storage means to the broadcasting station;
A terrestrial digital broadcasting system characterized by comprising:
[0172]
(Supplementary note 3) The broadcasting station has a pay broadcasting management mechanism for managing pay broadcasting, and pays for the receiver of the application source when receiving an application for pay broadcasting from the viewer through the receiver. The terrestrial digital broadcasting system according to Supplementary Note 1 or Supplementary Note 2, wherein the broadcast information is transmitted, and the broadcast information is updated by updating the decryption information of the receiver.
[0173]
(Additional remark 4) When the said broadcast station updates the decoding information of each said receiver, it transmits the broadcast signal which multiplexed the old and new decoding information, and the said receiver and the decoding information memorize | stored in the said memory | storage means The terrestrial digital broadcasting system according to appendix 1, 2, or 3, wherein the new and old decoding information of the broadcast signal transmitted from the broadcasting station is collated and updated to new decoding information.
[0174]
(Supplementary Note 5) When the broadcast station notifies each receiver of the update of the decryption information, it is unique encryption information predetermined for each user, and the encryption information for encrypting the broadcast signal is The terrestrial digital broadcasting system according to any one of appendices 1 to 4, wherein authentication information encrypted by encryption information to be encrypted is mixed in a transmission signal.
[0175]
(Supplementary note 6) The broadcast station inserts time information into a transmission signal, and the receiver refers to the inserted time information and does not update predetermined decoding information within a continuous period of time. In such a case, the terrestrial digital broadcasting system according to any one of appendices 1 to 5, wherein the predetermined decoding information is invalidated.
[0176]
(Supplementary note 7) The broadcast station encrypts the time information based on the encryption information, and the receiver decrypts the encrypted time information based on the decryption information. The terrestrial digital broadcasting system according to appendix 6.
[0177]
(Supplementary note 8) A terrestrial digital broadcast right protection device for receiving and processing terrestrial digital broadcast from a broadcasting station,
Storage means for previously storing decryption information for decrypting a transmission signal allocated and encrypted in predetermined units to one or more receivers supplied for the terrestrial digital broadcasting system; ,
Receiving means for receiving a transmission signal in which encryption information for rights protection and an encrypted broadcast signal are superimposed;
Reproducing means for reproducing the broadcast signal by decoding the transmission signal received by the receiving means according to the decoding information stored in the storage means;
A terrestrial digital broadcasting rights protection device characterized by comprising:
[0178]
(Supplementary note 9) A terrestrial digital broadcasting rights protection device for receiving and processing terrestrial digital broadcasting from a broadcasting station,
Decoding information and user-specific encryption information for decrypting a transmission signal that is allocated and encrypted in predetermined units to one or more receivers supplied for the terrestrial digital broadcasting system is stored in advance. Storage means,
Receiving means for receiving a transmission signal transmitted from the broadcasting station, wherein the transmission information on which encryption information for rights protection and an encrypted broadcast signal are superimposed;
Reproducing means for reproducing the broadcast signal by decoding the transmission signal received by the receiving means according to the decoding information stored in the storage means;
Individual receiving means for receiving user-specific service information returned from the broadcasting station by transmitting user-specific encryption information stored in the storage means to the broadcasting station;
A terrestrial digital broadcasting rights protection device characterized by comprising:
[0179]
(Supplementary Note 10) When a broadcast signal obtained by multiplexing old and new decoded information transmitted from the broadcast station is received by the receiving means, the decoded information stored in the storage means and the broadcast transmitted from the broadcast station 10. The terrestrial digital broadcast right protection device according to appendix 8 or 9, further comprising an update unit that compares the new and old decoding information of the signal and updates the new decoding information according to the coincidence of the old decoding information.
[0180]
(Supplementary note 11) The terrestrial digital broadcast right protection device according to supplementary note 10, wherein when the matching of the old decryption information cannot be confirmed by the collation, the update means notifies the inability to view due to the absence of decryption information .
[0181]
(Supplementary Note 12) When a transmission signal including decryption information for update is received from the broadcasting station, the transmission signal is encrypted information unique to each user and encrypted in advance. When authentication information encrypted by encryption information for encrypting encryption information is mixed, the authentication information is decrypted with reference to the storage means, and then the decryption information is updated. The terrestrial digital broadcast right protection device according to any one of appendices 8 to 11.
[0182]
(Supplementary note 13) Supplementary notes 8 to 12, wherein the decoding information includes preliminary decoding information, and when the transmission signal includes a revoke command, the decoding information is switched to the preliminary decoding information. The terrestrial digital broadcast right protection device according to any one of the above.
[0183]
(Additional remark 14) Time information is inserted in the transmission signal, and when the predetermined decoding information is not updated within a certain continuous time with reference to the inserted time information, the predetermined decoding is performed. The digital terrestrial broadcast right protection device according to any one of appendices 8 to 13, wherein the information is invalidated.
[0184]
(Supplementary note 15) The digital terrestrial broadcasting according to supplementary note 14, wherein the time information is encrypted based on the encryption information, and the encrypted time information is decrypted based on the decryption information. Rights protection device.
[0185]
(Supplementary note 16) The decryption information to be updated includes an encrypted broadcast signal of the transmission signal and a work key for decrypting the encrypted information obtained by encrypting the broadcast signal. The terrestrial digital broadcast right protection device according to any one of the above.
[0186]
【The invention's effect】
As explained above, The present invention According to the transmitter, the content information encrypted with the content key, the first signal with the content key encrypted with the second key, and The first key is the same as the first key stored in the storage unit of the receiver. The first key of at least one unit of lot unit, model unit, or manufacturer unit A transmission signal is generated by superimposing the second signal encrypted by the transmitter, the generated transmission signal is transmitted, and the receiver is allocated to one or more receivers supplied for the communication system. Units, model units, And the first key per manufacturer , and , Memorize the second key in advance, receive the transmitted signal and send the received signal The first key with the second signal encrypted at the transmitter and Since the content information is reproduced by decrypting according to the second key, there is an effect of realizing a communication system with a simple configuration and an inexpensive right protection function.
[0187]
Also, The present invention According to the transmitter, the content information encrypted with the content key, the first signal with the content key encrypted with the second key, and The first key is the same as the first key stored in the storage unit of the receiver. The first key of at least one unit of lot unit, model unit, or manufacturer unit When generating a transmission signal by superimposing the second signal encrypted by the transmission, transmitting the generated transmission signal, and receiving a user key for each user who uses the receiver from the receiver, the receiver receives On the other hand, service information related to services provided in the communication system is encrypted with the user key and transmitted to each user, and the receiver is allocated to one or more receivers supplied for the communication system. Lot unit, model unit, And the manufacturer unit The first key, and , Store the second key and user key in advance, receive the transmitted signal transmitted, The first key with the second signal encrypted at the transmitter and The content information is reproduced by decoding according to the second key, the user key is transmitted to the transmitter, and the user-specific service information returned from the transmitter is received. The protection function is realized, and there is an effect that a service for each individual user is provided from the transmitter to the receiver in response to the service request.
[0188]
Also, The present invention When the receiver receives the transmission signal generated from the content information and the first signal, the receiver encrypts the second key stored in the storage unit and the received first signal. The content key is extracted from the first signal on the condition that the key matches, and the encrypted content information is decrypted. The transmitter uses the second key from the old second key. When updating to the new second key, the content key encrypted with the new second key and the content key encrypted with the old second key during the predetermined grace period set as the grace period A second signal in which the new second key and the old second key are encrypted by the first key during the grace period. Is transmitted to the receiver, and the receiver transmits the transmitted second signal. Upon reception, the second signal is decrypted with the first key stored in the storage unit of the receiver, the new second key and the old second key are extracted from the second signal, and the storage unit stores the new second key and the old second key. The current second key, which is the stored second key, is compared with the new second key and the old second key that have been taken out. Only when a match between the second key and the old second key is confirmed, the current second key is updated to the new second key and the new second key is stored in the storage unit. Therefore, it is possible to make the receiver discriminate between the new and old of the second key, and there is an effect that the receiver is updated to the latest second key.
[0189]
Also, The present invention According to the above, when the second key update is notified from the transmitter to each receiver, the encryption information that is unique encryption information predetermined for each user and that encrypts the broadcast signal is stored. Since the authentication information encrypted by the encryption information to be encrypted is mixed in the transmission signal, there is an effect of confirming the validity of the information received in the right protection LSI.
[0191]
Also, The present invention According to the receiver, a lot unit, a model unit, allocated to one or more receivers supplied for the communication system, And by manufacturer The first key, and , The second key is stored in advance, the content information encrypted with the content key in the transmitter, the first signal with the content key encrypted with the second key, and The first key stored in the storage unit of the receiver One of Receive the transmission signal generated and transmitted by superimposing the second signal encrypted with the same first key as the received transmission signal First key and Since the content information is reproduced by decoding according to the second key, there is an effect that the content information is received with a simple configuration and an inexpensive right protection function.
[0192]
Also, The present invention When the transmitter receives a user key for each user who uses the receiver from the receiver, the transmitter encrypts service information related to services provided in the communication system to the receiver using the user key. And is transmitted to each user individually. The receiver is a lot unit, a model unit, or a unit allocated to one or more receivers supplied for the communication system. And by manufacturer The first key, and , A second key and a user key for each user who uses the receiver are stored in advance, the content information encrypted with the content key in the transmitter, and the content key encrypted with the second key One signal, and Receiving a transmission signal generated and transmitted by superimposing a second signal encrypted with a first key identical to the first key stored in the storage unit of the receiver. The received transmission signal One of the first keys and The content information is reproduced by decoding according to the second key, the user key is transmitted to the transmitter, and the user-specific service information returned from the transmitter is received. The protection function is realized, and there is an effect that the service for each individual user is enjoyed with respect to the service request.
[0193]
Also, The present invention When the receiver receives the transmission signal generated from the content information and the first signal, the receiver encrypts the second key stored in the storage unit and the received first signal. The content key is extracted from the first signal on the condition that the key matches, and the encrypted content information is decrypted. The transmitter uses the second key from the old second key. When updating to the new second key, the content key encrypted with the new second key and the content key encrypted with the old second key during the predetermined grace period set as the grace period A first signal including the second key and the old second key are encrypted by the first key during the grace period. The second signal transmitted to the receiver, When the receiver receives the second signal transmitted by the transmitter during the grace period, the receiver decrypts the second signal with the first key stored in the storage unit of the receiver, The new second key and the old second key are extracted from the signal, the current second key, which is the second key stored in the storage unit, and the extracted new second key and old second key. Are compared with each other, and if the comparison results in a match between the current second key and the old second key, the current second key is replaced with the new second key. Since the new second key is stored in the storage unit by updating the key to the new key, there is an effect of distinguishing between new and old decryption information and updating to the latest decryption information.
[0194]
Also, The present invention According to the above, when the match of the current second key with either the new second key or the old second key is not confirmed, it is informed that viewing is impossible due to the absence of decryption information. Effect of supporting the confirmation of the inability to view by the user.
[0195]
Also, The present invention According to the above, since the transmission by the transmitter is transmission by broadcast waves, there is an effect of realizing, for example, a terrestrial digital broadcasting system with a simple configuration and an inexpensive right protection function.
[Brief description of the drawings]
FIG. 1 is a diagram showing a terrestrial digital broadcast right protection system according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a configuration example of a receiver according to the first embodiment.
FIG. 3 is a diagram illustrating a bit pattern according to the first embodiment.
4 is a block diagram schematically showing a configuration example of a right protection LSI according to the first embodiment; FIG.
FIG. 5 is a flowchart illustrating an operation during digital terrestrial broadcasting according to the first embodiment.
FIG. 6 is a diagram showing a terrestrial digital broadcast right protection system according to a second embodiment of the present invention.
FIG. 7 is a diagram showing a terrestrial digital broadcast right protection system according to a third embodiment of the present invention.
FIG. 8 is a block diagram schematically showing a configuration example of a right protection LSI according to a third embodiment.
FIG. 9 is a flowchart illustrating an operation during digital terrestrial broadcasting according to the third embodiment.
FIG. 10 is a diagram showing a digital terrestrial broadcast right protection system according to a fourth embodiment of the present invention.
FIG. 11 is a block diagram schematically showing a configuration example of a right protection LSI according to a fourth embodiment.
FIG. 12 is a flowchart illustrating an operation during digital terrestrial broadcasting according to the fourth embodiment.
FIG. 13 is a block diagram schematically showing a configuration example of a right protection LSI according to a fifth embodiment.
FIG. 14 is a flowchart illustrating an operation during digital terrestrial broadcasting according to the fifth embodiment.
FIG. 15 is a diagram for explaining an example of a packet during digital terrestrial broadcasting according to the sixth embodiment.
FIG. 16 is a block diagram schematically showing a configuration example of a right protection LSI according to a sixth embodiment;
FIG. 17 is a flowchart illustrating an operation during digital terrestrial broadcasting according to the sixth embodiment.
FIG. 18 is a diagram for explaining an example of a packet at the time of digital terrestrial broadcasting according to the seventh embodiment.
FIG. 19 is a flowchart illustrating an operation during digital terrestrial broadcasting according to the seventh embodiment.
FIG. 20 is a diagram for explaining revoke transmission according to the eighth embodiment.
FIG. 21 is a diagram explaining ECM transmission according to the eighth embodiment.
FIG. 22 is a block diagram illustrating an example of a network of a terrestrial digital broadcasting system according to the present invention.
FIG. 23 is a configuration diagram illustrating another example of the network of the terrestrial digital broadcasting system according to the present invention.
[Explanation of symbols]
1A, 1B, 1C, 1D management mechanism
2A, 2B, 2C, 2D IDC
3A, 3B, 3C, 3D LSI manufacturer
4A, 4B, 4C, 4D Receiver manufacturer
5 broadcast stations
5A, 5B, 5C, 5D broadcasting stations
6 receivers
6A, 6B, 6C, 6D receiver
7 Internet line
7D IDC
8 VPN line
63A, 63C, 63D, 63E, 63F Rights protection LSI

Claims (10)

A communication system comprising a transmitter and a receiver for transmitting / receiving content information encrypted with a content key,
The transmitter is
Content information encrypted with the content key, the first signal with the content key encrypted with the second key, and the second key identical to the first key stored in the storage unit of the receiver Generating means for generating a transmission signal by superimposing a second signal encrypted by a first key of at least one unit among a lot unit, a model unit, or a manufacturer unit ;
Transmitting means for transmitting the transmission signal generated by the generating means;
With
The receiver
Storage means for storing in advance the first key and the second key in lot units, model units, and manufacturer units allocated to one or more receivers supplied for the communication system When,
Receiving means for receiving a transmission signal transmitted by the transmitting means;
Content information by decrypting the transmission signal received by the receiving means according to the second key encrypted in the transmitter and the first key stored in the storage means according to the second key Playback means for playing
A communication system comprising: A communication system comprising a transmitter and a receiver for transmitting / receiving content information encrypted with a content key,
The transmitter is
Content information encrypted with the content key, the first signal with the content key encrypted with the second key, and the second key identical to the first key stored in the storage unit of the receiver Generating means for generating a transmission signal by superimposing a second signal encrypted by a first key of at least one unit among a lot unit, a model unit, or a manufacturer unit ;
Transmitting means for transmitting the transmission signal generated by the generating means;
When a user-specific user key using the receiver is received from the receiver, service information related to a service provided in the communication system is encrypted with the user key for the receiver. Individual transmission means for transmitting to
With
The receiver
Batches allocated to one or more receivers that are supplied for the communication system, the first key model unit, and manufacturers units, and a second key, and stores in advance a user key Storage means to keep,
Receiving means for receiving a transmission signal transmitted by the transmitting means;
Content information by decrypting the transmission signal received by the receiving means according to the second key encrypted in the transmitter and the first key stored in the storage means according to the second key Playback means for playing
Individual receiving means for transmitting the user key stored in the storage means to the transmitter and receiving user-specific service information returned from the transmitter;
A communication system comprising: When the receiver receives the content information and the transmission signal generated from the first signal by the generation means, the receiver encrypts the second key stored in the storage unit and the received first signal. On the condition that the second key matches, the content key is extracted from the first signal, and the encrypted content information is decrypted.
The transmitter is
When the second key is updated from the old second key to the new second key, the content key encrypted with the new second key and the old key during the predetermined grace period set as the grace period Updating first signal transmitting means for transmitting a first signal including a content key encrypted by a second key to the receiver;
During the grace period, a second signal transmitting means for updating that transmits a second signal obtained by encrypting the new second key and the old second key with the first key to the receiver;
Further comprising
The receiver
When receiving the second signal transmitted by the second signal transmission means for updating, the second signal is decrypted by the first key stored in the storage unit of the receiver, and the second signal is newly generated from the second signal. The second key and the old second key are extracted, and the current second key that is the second key stored in the storage unit matches the new second key and the old second key that are extracted. A second key comparison means for comparing whether or not
As a result of the comparison by the second key comparison means, the update from the current second key to the new second key is performed only when the match between the current second key and the old second key is confirmed. Second key updating means for performing and storing the new second key in the storage unit;
The communication system according to claim 1, further comprising:   When notifying the receiver of the second key update from the transmitter, the encryption information that is unique encryption information predetermined for each user and encrypts the broadcast signal is encrypted. The communication system according to any one of claims 1 to 3, wherein authentication information encrypted by encryption information is mixed in a transmission signal. A receiver of a communication system comprising a transmitter and a receiver for transmitting and receiving content information encrypted by a content key,
Storage means for storing in advance a first key and a second key of a lot unit, a model unit, and a manufacturer unit allocated to one or more receivers supplied for the communication system; ,
The content information encrypted by the content key in the transmitter, the first signal in which the content key is encrypted by the second key, and the first key stored in the storage unit of the receiver Receiving means for receiving a transmission signal that is generated by superimposing a second signal encrypted by the same first key as any one of the keys, and transmitted from the transmitter;
Reproducing means for reproducing the content information by decoding the transmission signal received by the receiving means according to the first key and the second key stored in the storage means;
A receiver comprising: A receiver of a communication system comprising a transmitter and a receiver for transmitting and receiving content information encrypted by a content key,
When the transmitter receives a user key for each user who uses the receiver from the receiver, the transmitter uses the user key to provide service information regarding services provided in the communication system to the receiver. It is encrypted and sent to individual users.
The receiver
Batches allocated to one or more receivers that are supplied for the communication system, the first key model unit, and manufacturers units, and a second key, and, using the receiver Storage means for storing user-specific user keys in advance;
The content information encrypted by the content key in the transmitter, the first signal in which the content key is encrypted by the second key, and the first key stored in the storage unit of the receiver Receiving means for receiving a transmission signal that is generated by superimposing a second signal encrypted by the same first key as that of the key and transmitted from the transmitter;
Reproduction means for reproducing content information by decrypting the transmission signal received by the reception means according to any one of the first keys stored in the storage means and the second key;
Individual receiving means for transmitting the user key stored in the storage means to the transmitter and receiving user-specific service information returned from the transmitter;
A receiver comprising: When the receiver receives the transmission signal generated from the content information and the first signal, the receiver stores a second key stored in the storage unit and a second key obtained by encrypting the received first signal. And the content information is extracted from the first signal, and the encrypted content information is decrypted on the condition that
When the transmitter updates the second key from the old second key to the new second key, the transmitter is encrypted with the new second key during a predetermined grace period set as a grace period. A first signal including a content key and a content key encrypted by the old second key is transmitted to the receiver; and during the grace period, Transmitting a second signal in which a second key and an old second key are encrypted by the first key to the receiver;
The receiver
When the second signal transmitted by the transmitter is received during the grace period, the second signal is decrypted by the first key stored in the storage unit of the receiver, and the second signal is updated from the second signal. The second key and the old second key are extracted, and the current second key that is the second key stored in the storage unit matches the new second key and the old second key that are extracted. A second key comparison means for comparing whether or not
As a result of the comparison by the second key comparison means, the update from the current second key to the new second key is performed only when the match between the current second key and the old second key is confirmed. Second key updating means for performing and storing the new second key in the storage unit;
The receiver according to claim 5 or 6 , further comprising: The second key updating means cannot confirm the coincidence of the new second key and the old second key with respect to the current second key by the second key comparing means. The receiver according to claim 7 , wherein the receiver is notified that viewing is impossible due to the absence of decoding information. The transmission by the transmitter, a communication system according to any one of claims 1-4, characterized in that the transmission by broadcast waves. The receiver according to claim 5 , wherein the transmission by the transmitter is transmission by a broadcast wave.

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