A system for controlling access to broadcast transmissions

Description: TECHNICAL FIELD [Detailed description of the invention]

Industrial application field The present invention relates to a broadcast transmission system and technology. Conventional technology A wide variety of systems and techniques for broadcast transmission are known in the patent literature. More specifically, systems for controlling access to broadcast transmissions are described in the following publications: "Satellite and Cable TV Scrambling and Descrambling" by Brent Gale and Frank Baylin (1986, published by Gale Productions in Bruda, Colorado) ) Smart cards, which are plastic cards similar to credit cards with a microprocessor inside, are known in the art. These are described in the book "Smart Cords, The New Bank Cards" by Jerome Svigals, published by McMillan Publishing Company in New York, 1987. .. Problems to be solved and means for that The present invention seeks to provide improved devices and techniques for controlling access to broadcast transmission. For the purposes of this specification and the claims of the present invention, broadcast transmissions, whether transmitted by wire or by wireless technology, may be a combination of both audio and video or separately. It shall include. Therefore, according to a preferred embodiment of the present invention, a system for controlling access to broadcast transmission is provided. The system has a transmitter with a transmit encoder to scramble the broadcast and an equivalent receive decoder with a large number of subscriber receivers, each of which does not include a secret encryption key for descramble the broadcast. A large number of subscriber receivers and multiple selectable and portable executables, each of which is operationally related to and generally equivalent to the receiving decoder at a given time that is partially different. Includes multiple selectable and portable performers, which implement and thereby generate seeds for use by the associated receive decoder, which allows the receive decoder to descramble the broadcast. According to a preferred embodiment of the present invention, the executing device includes a device for actively executing the algorithm. According to another embodiment of the invention, the executing device includes a device for providing instructions and data for an algorithm performed in the decoder. According to one embodiment of the invention, the executing device provides all of the instructions required to transmit descramble. According to another embodiment of the invention, the executing device provides only some of the instructions required to descramble the transmission. According to a preferred embodiment of the present invention, the executing device includes a device for supplying a proof of authenticity to the receiving decoder. This authenticity proof is preferably a genuine public key proof, and is preferably a genuine Fiat-Shamir public key proof. According to a preferred embodiment of the present invention, each execution device includes an independent identification element that can be detected by the decoder. Further, according to a preferred embodiment of the present invention, each execution device includes an element indicating the program viewing qualification to the decoder. According to a preferred embodiment of the present invention, the element indicating the program viewing qualification to the decoder is modified by the information contained in the transmitted broadcast. According to a preferred embodiment of the present invention, the decoder includes a mail box for receiving the decoder from broadcast transmission and from the first of a plurality of selectable execution devices. Further, according to a preferred embodiment of the present invention, the execution device can be operated to access the mail box. Such data may include, for example, start-up data and qualification information to enable operation of the execution device. According to a preferred embodiment of the present invention, the execution device may include information accessible to the decoder to modify the software of the decoder. According to a preferred embodiment of the present invention, the executing device includes a device for generating a display message via a decoder. According to a preferred embodiment of the present invention, the decoder can be actuated to generate display messages from any of the following sources: broadcasts, decoders and execution devices. Further, according to a preferred embodiment of the present invention, the display message can be assigned a designated priority. According to the present invention, a system for transferring information, a card device including a plurality of portable card devices for generating and transmitting data to be stored, and a plurality of the above. To receive data from the first of the card devices, to store the data, and to allow the second of the plurality of card devices to remove data from it. A system is provided that includes a fixed storage device for. According to the present invention, it is a system for transferring information, a computing device for generating and transmitting a first set of data to be stored, and a second set of data to be generated and transmitted by each. Information for receiving at least one of the first and second data from a plurality of portable card devices including the microprocessor device of the above, and the first of the computing device and the plurality of card devices. A fixed storage for storing the data and for allowing the second of the plurality of card devices to remove at least one of the first and second data from the data. A system, including a device, is further provided. Example First, FIGS. 1A and 1B to 3 will be described. These figures illustrate a broadcast system that can be configured and operated according to preferred embodiments of the present invention. The broadcast system preferably includes a security computer 10, such as an IBM AT with multiple serial communication links. This secure computer 10 is IBM Received input from a security database computer 12 such as AT, the computer 12 stores not only programming information but also information related to emergency or regular subscriber behavior. In general, emergency subscriber behavior can consist of an immediate online launch, cancellation, or restart of view entitlement. Regular subscriber behavior is typically a blacklist roster order or a message that is transmitted on a regular basis, and when the subscriber is tuned to the system, the order or message is received and processed appropriately. The security computer 10 also receives input from a subscriber management system 14, typically implemented on large mainframe computers commercially available from IBM or other major manufacturers. This subscriber management system remembers the details of all subscribers, their payment status, and their entitlement. According to a preferred embodiment of the invention, the security computer 10 interfaces with one or more smart cards 16. Such smart cards are well known and are described in "Smart Cards as New Bank Cards" by Jerome Sbigals. These smart cards preferably include two computer programs. Its first computer program includes a seed generation algorithm for generating seeds for signal scrambling and descrambles on both sides of the system. The second program includes a signature protocol that adds an appropriately hashed signature to all information regarding entitlement when transmitted over the system. The security computer 10 supplies data, including data, especially unscrambled data, signatures and seeded data, to an encoder 18, which is usually located on the premises of a broadcasting station. The operation of the devices at elements 10, 12, 14 and 16 can be emulated by a computer program (its object code attached as reference A). Encoder 18 is usually an encoder commercially available from Thomson CSF Laboratowa Electronics de Lenne in Saison-Sevin, France. The encoder 18 operates to scramble all or part of an audio-video TV program received from any suitable program source, such as a VCR, using seeds received via the security computer 10. The encoder 18 also modulates the data it receives from the security computer so that it can scramble it and send both the program and the data together. Note that the seed is not modulated and therefore does not transmit. This modulation technique can be arbitrarily selected from known techniques, provided that it is suitable for use with this encoder 18. According to a preferred embodiment of the invention, the data is inserted into an unused video line. The output of the encoder 18 is broadcast by any suitable technique, either by a wired or wireless device. In the illustrated embodiment, the encoder outputs to ground station 20, which communicates with a number of receiving ground stations 24, each representing a subscriber, via satellite 22 in geostationary track. The signal received by each receiving ground station 24 is typically supplied to a commercially available receiver 26 in Amstrad, England. The receiver 26 operates to convert the received signals (these signals are selected by the subscriber) into baseband video signals. If this baseband video signal does not require descramble, receiver 26 remodulates the baseband video signal on a preselected channel for reception and display on a conventional television display 28. .. The scrambled signal is supplied by the receiver 26 to the decoder 30 (usually Ferguson Limited in Middlesex, England or LEREA, commercially available in Ilkirch, France). According to a preferred embodiment of the invention, the decoder works with a smart card 32 that includes a seed generation algorithm. One feature of the present invention is that these decoders do not contain cryptographic secrets, and each of the smart cards 32 associated with their many receivers 26 is equivalent to the data sent from the secure computer 10. Is to implement the seed generation algorithm of, and thus to generate the same seeds that the encoder 18 used to scramble the broadcast signal. Another feature of the present invention is that these receivers 26 are equivalent so that a smart card 32 from one subscriber can operate on the second subscriber's receiver 26, thereby allowing the second subscriber. However, the program received by the first subscriber can be viewed at home. According to alternative embodiments of the present invention, the use of either or both of smart cards 16 and 32 can be excluded for simpler and less secure memory cards. In such cases, the memory card contains the data but not the seed generation algorithm. In such a case, the security computer 10 sends a command to the decoder 30 to allow the decoder 30 to regenerate the seed using the data in its memory card. In embodiments where cards 16 and 32, or at least card 32, is a smart card, smart card 32 takes no signature by verifying the authenticity of the hashed signature generated by card 16 and transmitted through the system. Includes a first program, which eliminates entitlement data that has no or non-authentic signatures. The smart card 32 also contains a program that causes the decoder to generate seeds for descrambled video TV programs. The object code for the smart card 32 manufactured by News Gem Smart Card International Ltd. in Livingston, Scotland is attached here as Reference B. Here, reference is made to FIG. 2 showing the transmitter of the present invention. As mentioned above, the security computer 10 receives subscriber and programming data from the subscriber management system 14 and the security database 12. The security computer 10 smartly transfers a portion of its data related to the action to be performed by the smart card 32 via the smart card coupler 34, for example, the Gemplus commercially available smart card coupler from Gemenos, France. Send to card 16. The smart card 16 attaches a digital signature to its data for the smart card 32, thereby allowing the digital signature to be generated by a second algorithm stored within the smart card 16. The smart card 16 also generates seeds for scrambling used by the encoder 18. The two algorithms stored on smart cards 16 and 32 are usually hashing functions that act on the data for smart cards 32. Its hashing function of the second algorithm for digital signature generation usually iterates several times. The hashing function of the first algorithm for seed generation usually iterates many times. The hashing function is described in Donald E. Knuth, "Computer Programming Technology Volume 2: Half-Numeric Algorithms". Data for the smart card 32 and seeds for scrambling are sent from the smart card 16 through the security computer 10 to the encoder 18. The scrambling species is loaded into the pseudo-random bit sequencer (PRBS) 40, which produces bits for the pseudo-random sequence from this species. The bits of this sequence are sent to the scrambler 42, which uses it to scramble the broadcast signal that can be generated from the VCR. The data for the smart card 32 as well as the programming and security data is added to the scrambled broadcast signal by the data inserter 44, and the composite signal is sent to the ground station 20, modulated and transmitted. To. Here, refer to FIG. 3 which shows the receiving side of the system of FIGS. 1A and 1B. As mentioned above, the combined signal is received by the receiving ground station 24 and sent to the receiver 26, which demodulates this signal into video baseband. This video baseband is then sent in parallel to both the descrambler 46 of the decoder 30 and the data demodulator 48. The data demodulator 48 extracts data from the composite signal and sends it to the verifier 50. The verifier 50 then sends a portion of the data to the smart card 32 for qualification verification and seed generation. That part of the data sent is the part that deals with qualification and seeding. If the smart card 32 receives its data portion and the entitlement information contained therein indicates that the subscriber is entitled to view the program of his choice, the smart card said. The data portion is used to generate a seed for decoding that is generally equivalent to a seed for scrambling. If the subscriber is not entitled to receive the video signal, the decoding species will not match the scrambling species. The smart card 32 also produces an on-screen display based on its received data portion. For example, the received data portion usually contains a channel identification number and a current date. If the subscriber is not entitled to watch the currently selected channel, it will generate an on-screen message, for example "THIS CHANNEL IS BLOCKED". If the current date exceeds the maturity date stored on the smart card 32, a message displayed on the screen, for example "YOUR CARD HAS" It will generate "EXPIRED (your card has expired)". It should be understood that normally only one on-screen message can be displayed at a time. The generated species and on-screen display, if any, are sent to the verifier 50. The verifier 50 sends its on-screen display to the on-screen display inserter 52, which inserts the display into the baseband video signal after exiting the descrambler 46. The above decoding species is sent to the PRBS54, which generates a pseudo-random bit sequence that is generally equivalent to the scrambling species, which is utilized by the descrambler 46 to descramble the baseband video signal. To do. The verifier 50 is designed to perform six additional functions: 1. Confirmation operation described below with reference to Fig. 6 to verify the authenticity of the smart card. 2. Generation of decryption species associated with security computer 10 and management of pay-per-view programs in an embodiment in which the smart card 32 consists of a memory card. The algorithm used for seed generation is a hashing function that acts on the data from the security computer 10. This result is used as a decryption species when the result of the instruction such as comparison between the data stored in the memory card and the data sent from the security computer 10 is positive. 3. Decide which message to display and send that message to the on-screen display inserter 52, for example, the on-screen message generated by the smart card 32 and the on-screen message sent by the security computer 10. Comparison of on-screen message priority levels with display messages. 4. Display of smart card 32 identification number when requested by security computer 10. 5. Blacklist smart card 32 with illegal identification number as directed by security computer 10. as well as 6. Mailbox maintenance used to store messages from old smart cards to new smart cards and to store messages from computer 10 to smart card 32. Such messages can include enabling new cards based on messages left by old cards. In the case of a viewing unit payment system where the smart card 32 now remembers the amount initially paid by the subscriber and deletes the prescribed amount for each program viewed, at the end of the subscription period, the old smart card 32 Leave the remaining amount (if any) for the subscriber in the mail box. The new smart card 32 adds the amount left in the mailbox to the amount stored in it. The actionable code for the verifier 50 built into an Intel 8052 processor is attached here as Reference C. The on-screen display inserter 52 inserts the on-screen display message into the baseband video output of the descrambler 46, and this composite signal is sent to the receiver 26 for remodulation and transmission to the TV set 28. Here, reference is made to FIG. 4, which shows a communication protocol normally used in the system of the present invention. Starting from the lowest physical level, the ground station transmitter 20 transmits the broadcast signal via the satellite link to the ground station receiver 24 and the receiver device 60 constituting the receiver 26. At the data level, the data is inserted into the vertical blanking interval of the broadcast signal via the data inserter 44 of the encoder 18 and removed via the data demodulator 48 of the decoder 30. These encoders 18 and decoders 30 can be made to communicate with each other without affecting the operation of the system according to the present invention. At the session level, the security computer 10 communicates with the verifier 50 of the decoder 30 via a data packet of that data. In a preferred embodiment of the invention, those data packets are 32-byte packets. The information that passes is, as described above, the information of the system and the subscriber, that is, the authorization to perform the verification operation and / or to display the smart card identification number. This session level is via the RS-232 protocol between the secure computer 10 and the encoder 18 and via the parallel communication protocol described in Reference D between the verifier 50 and the data modulator 48. And communicate with the data level. Finally, the application level is the communication level between the smart card 16 mounted on the security computer 10 and the smart card 32 mounted on the decoder 30. The information that passes is related to species and signature outbreaks, as well as channel and date information. Now refer to FIG. 5, which shows the communication protocol between the smart card 32 and the verifier 50. The verifier 50 sends a data packet to the smart card 32, which acts on the data packet to generate a decryption species and an on-screen message. Further, the smart card 32 not only receives the mail from the mail box of the verifier 50, but also sends the mail to the mail box. According to a preferred embodiment of the present invention, the verifier 50 reads the card identification number (ID) of the smart card 32 stored in the memory of the smart card. In addition, the verifier 50 and smart card 32 carry out a verification process when instructed by the security computer 10 to be transmitted in a data packet. This confirmation process is shown in Figure 6 and is described in detail in US Pat. No. 4,748,668, which is cited herein. The smart card 32 stores the card identification number indicated by V in FIG. 6, the second number indicated by S, and the modulus N, which is also stored in the verifier 50. N is a public modulus that is a multiple of the two values P and Q, where P and Q are two prime numbers, usually many digits, known only to systems that generate smart cards. S is defined as follows.<img file="JPP3199119B2_D0001.tif" /> Here, the square root is achieved as a modular square root. Modular arithmetic is discussed in "Computer Programming Techniques Vol. 2: Half-Numeric Algorithms" by Donald E. Nath, published by Addison-Wesley Publishing Campani, Leading Massachusetts, pp. 268-278. The verification process works as follows. The verifier 50 requests a number X from the smart card 32. Here, X is defined as follows. X = R^2*ModN (2) Where R is any number. The verifier 50 then responds with a question bit Q (whose value is randomly 0 or 1) received from the security computer 10. The smart card 32 then responds with the value Y. Here, Y is defined as follows. Y = R (when Q = 0) (3) Y = (R^*S)^*ModN (when Q = 1) (4) For smart card 32, verifier 50 is Y²When calculating the following values for, it is confirmed. Y²= X^*ModN (when Q = 0) (5) Y²= (X^*V)^*ModN (when Q = 1) (6) Here, the verifier 50 receives a V from the smart card 32 prior to this verification process. As will be appreciated by those skilled in the art, the present invention is not limited to those shown and described in detail.

[Simple explanation of drawings]

1A and 1B are overall block diagrams of a broadcasting system that can be configured and operated according to preferred embodiments of the present invention. Fig. 2 is a more detailed block diagram of the transmitting side of the system in Fig. 1A and Fig. 1B. FIG. 3 is a more detailed block diagram of the receiving side of the system of FIGS. 1A and 1B. FIG. 4 is an overall view of a communication protocol adopted according to a preferred embodiment of the present invention. FIG. 5 is a diagram of an information exchange protocol used in a verifier and a smart card according to a preferred embodiment of the present invention. FIG. 6 is a diagram of the Fiat-Shamir confirmation protocol useful in the present invention. 10 ...... Confidential computer, 12 ...... Confidential database computer, 14 ...... Subscriber management system, 16 ...... Smart card, 18 ...... encoder, 20 ...... Ground station, 22 ...... Satellite, 24 ...... Receiving ground station, 26 ...... Receiver, 28 ...... Television Display, 30 ...... Decoder, 32 ...... Smart card, 44 ...... Data inserter, 46 ...... Desk Rambra, 48 ...... Data modulator, 50 ...... verifier, 52 ...... On-screen display (OSD) inserter.