JPS62503066A - Method and apparatus for scrambling and descrambling television signals - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Name of invention) Method and apparatus for scrambling and descrambling television signals 〔Technical field〕 The present invention relates to the field of communication systems, and in particular to subscription television systems. for scrambling and descrambling of television signals in METHODS AND APPARATUS.

Subscriber television systems provide information and entertainment to the public. Widely accepted as an effective way to provide a wide selection of There is.

However, a quality system comes at a high cost. Therefore, for system maintenance Care must be taken to ensure adequate financial returns for broadcasting companies.

To this end, many broadcasting companies encourage payments from those requesting their services. Therefore, it is not necessary to rely on scrambling (intentional conversion of broadcast frequency bands) measures of broadcast signals. I have no choice but to.

Only subscribers to the broadcast system have decoding equipment to descramble the signal. (decoder).

Furthermore, the signal is only descrambled when the subscriber's vehicle is in good condition. A large number of decoders have been designed.

The fact that the John signal is extracted and displayed as a result of the line scanning process depends on. Image information consists of a series of consecutive horizontal lines transmitted sequentially in time. scanned using The signal sent out is based on each point on the line and its corresponding brightness intensity. It is a continuous analog quantity of Such a signal is shown in Figure 1; In a series of standard lines, two adjacent active line periods (bits) (period in which video information is transmitted) is separated by a period in which video information is not transmitted. You will understand. This latter period is known as the horizontal blanking period and is Allows the scanning device in the John receiver to be reset to the starting position of the line. It is inserted like this.

In a typical color television signal, this active line period is , three independent color components standardized in North America, Canada and Japan . This method is known as the NTSC standard. As P A L and SECAM Alternative standards known as NTSC standard including blanking period and active line period, and Other formats of analog video that offer improved picture quality compared to existing standards We are currently researching the O signal. These signals are for subscriber television. This is particularly important for the field, and the three independent periods in the active line period of the scan line. It is based on the temporal multiplexing of color components. NTSC, PAL or Instead of symbolizing the three components into one signal using the SECAM standard, these components The minutes are converted to digital form and transmitted sequentially using time compression methods. This form of belief One variation of the issue is known as MAC (Multiple Analog Components). time The signal produced by the compression method also depends on the blanking period and activation period on each scan line. Same as NTSC, PAL and SECAM standards including presence of active line period Stick to the basic format.

If a MAC signal is used, during the blanking period, as shown by the dotted line in Figure 2, Digital data can be sent to Therefore, the back part of the signal is converted to digital form and transmitted as digital data during the blanking period. I can do it. Therefore, the blanking period is often referred to as the "data channel", It may include several multiplexed data signals. color components, acoustic signals and All signals on the data channels of the television signal This is called the fence part.

When scrambling a television signal, the analog video component of the signal is The selected parameters of minutes are changed according to a pseudo-random scrambling code. . A decoder at the receiver reconfigures this into an appropriate format. Used to descramble video components. Data channels are also Can also be fully encoded to further negate reception of the signal by unauthorized persons. .

The terms "encoding" and "scramble" and their opposites "decoding" and "descanning" ``Crumble'' is often used interchangeably, but there is a clear difference in the terminology for ``Kowara''. be. Encoding and decoding are used on digital signals, including scrambling and decoding. and descrambling are used for analog signals. This usage is based on digital This occurs because of the fundamental difference between digital and analog signals. Digital signals are defined at the bit level, where a bit is independent of its neighboring bits . Any encoding, perversion, or inversion of the data bits that make up a signal is It does not affect the transmission characteristics of the signal at the net level. For this reason, 1 The encoded digital signal contains all the information present in the original signal and is The signal can be accurately restored to the original signal.

On the other hand, analog signal 1 can be modified or removed without affecting its transmission characteristics. Cannot be changed. For example, you can analyze an analog signal without touching neighboring points in the waveform. Changing the value at a point in the waveform increases the bandwidth of the signal. For this reason , the modified signal requires a wider bandwidth for accurate transmission. follow Therefore, when scrambling a single analog signal, there is almost no change in the transmission characteristics of the signal. Parameters must be selected that do not lead to

Scrambles television signals by modifying the analog color content of the signal Many methods can be used to do this. Such a method uses color components change the amplitude of the color component, change the time at which the color component is sent, and change the amplitude and and transmission time.

Of course, each change is made to the receiver in the data channel of the television signal. An example of a predetermined sample that can be sent is 5, which is assigned to the same assignee as the present application. U.S. Patent Application No. 507.765, filed 6124/1983, entitled Encoding and Decoding (Scramble and Descramble) Method".

This US patent application is incorporated herein by reference. The color component may also be e.g. AC television signals converted to digital form for time-compressed transmission It is also possible to encode in between. Such a symbolization method is the same assignee as the present application. No. 736,301, filed May 21, 1985, assigned to Disclosed in ``Method and Apparatus for Encoding and Decoding Television Signals'' It is shown. This US patent application is also incorporated herein by reference. Furthermore, Te The acoustic component of the revision signal shall be scrambled in its analog form. or converted to digital form and encoded in the data channel. and may be transmitted.

In a typical encoding system, the form of the digital data signal being encoded is The state is changed according to a pattern determined at the sender. This pattern is , in general, it is very difficult to discover patterns through laborious searches. This is one of a huge number of similar patterns. Putter used for symbolization The exact description of the This recipient can restore the original broadcast. The explanation of this pattern is This is known as the "encoding key J" in the The process of informing the Ru. This decryption key is obtained from the encoding key and decrypts the encoded information in its original form. allowed to return to.

Many encoding codes are available in the art for reliable encoding of digital data. It can be used as Fast enough for television signal data, multi-channel Integrated circuit devices are currently using algorithms for encoding and decoding exist. One such The algorithm is based on the Data Symbolization Standard adopted by the National Institute of National Standards. Encryption 5 standard, DES). Other algorithms encryption can also be used, the only requirement is that the data channel must be decrypted without the decryption key. It would be impossible if

Decoding codes for the color components of television signals and possibly acoustic information Symbolized data channels containing The decryption key for reading (i.e. the opposite of the encoding key) is the same for all users. It has to be something. However, due to the use of a common decryption key, the system Decryption keys for non-subscribers or subscribers who are not currently in good health. It is necessary that means be provided to prevent the dissemination of

(Summary of the invention) Therefore, it is an object of the present invention to provide reliable scrambling measures for television signals. The present invention provides methods and apparatus.

Another object of the invention is to encode illegal reception codes in television signals. be.

The use of a common decryption method is such that an unauthorized recipient cannot receive the key. must be distributed. One such method of providing this guarantee is to changing the decryption key at regular intervals (for example, every minute), thereby preventing unauthorized By removing legitimate users from the service, fair users can continue to receive updated decryption keys. Maintain a permanent link with a fair user so that you can receive. decoding key By integrating with the second decryption key acquisition system that invalidates unauthorized reception of be.

Method and method for reliable scrambling of television signals according to the invention The system consists of three levels of symbology. On the television transmitter side , a distributed key is used to encode one session (5ession) key. be done. This distribution key is unique for each subscriber and remains unchanged for a long time. . However, the session key is changed periodically, for example on a weekly or monthly basis. Record The encoded session key is then transferred to the digital data of the television signal. sent to the channel. The session ° key also symbolizes a descramble code. is used only. The descrambling code is Descrambling or unpacking various signals such as video components and/or audio study signals Contains multiple keys used by the recipient to read. descramble code The code is also changed periodically, for example four times every second, for added security. next The encoded descrambling code is the data channel of the television signal. Sent in .

On the receiving side, the session key is encoded to decode the descramble code. The encoded session key is decrypted by the distribution key so that it can be used.

This descrambling code then converts the scrambled video component and (or) descrambling or deciphering other signals, such as acoustic signals, at the receiver. It can be used to In another embodiment of the invention, the television An authentication code is also transmitted on the data channel of the signal. The recipient receives this Authentication code is a locally derived authentication code resulting from a decrypted session key. Contrasted with the code. If the two authentication codes match, the decrypted session key is - are allowed to decipher the descramble code. deciphered desk clan The bull coat then resolves the other signals at the receiver. 1 and 2 are graphs showing line-scanned television signals; FIG. 3 shows the descrambling of the intelligence portion of a television signal according to the present invention. of a system for symbolizing bulls and/or coats used for decoding A block diagram illustrating one embodiment, FIG. 4 shows the descrambling of the intelligence portion of a television signal according to the present invention. of the system for decoding the bull and/or code used for decoding A block diagram of one actual journey mode, 5, 6 and 7 illustrate the input of television signals according to the present invention. Descrambling (or) decoding of the code used for decoding A block diagram of another embodiment of the system for FIG. 2 is a block diagram of one implementation of a John decoder.

[Best mode for carrying out the invention]

FIGS. 3 and 4 illustrate scrambling measures for television signals according to the present invention. FIG. 2 is a block diagram of one implementation of a system for this purpose. Figure 3 shows symbolization on the sending side FIG. 4 shows the decoding operation on the receiving side. As shown in Figure 3 As such, the session key 30 is uniquely assigned to each subscriber and is long-term It is kept unchanged for a while. On the other hand, a session key is a predetermined interval, e.g. changes on a weekly or monthly basis. The encoding session key then is transmitted on the digital data channel of the signal. Sec5n Key is also used for encoding the descrambling code 31. descramble ・The code descrambles and/or decodes the various signals at the receiver. Contains Nodame's key. A stiff signal is a scrambled television signal a scrambled or encoded audio signal, and/or ) may include other signals that require descrambling or decoding at the receiving end. can. The encoded descrambling code also decodes the television signal. transmitted on a digital data channel. Descramble coat also , can be updated regularly, for example four times per second, for added security.

In FIG. 4, block 40 represents the symbolized cells as shown in FIG. Televisions with digital keys and encoded descrambling codes Represents the digital data channel on which the signal was received. Symbolized set The application key is provided to block 43 along with distribution key 41. This distribution The key is further allocated to the subscriber for paid subscription fees to the system. It will be done. This key is unique for each subscriber or prevents key exchange. It is part of a set of keys large enough to The distribution key 41 is arranged as shown in FIG. It may be the same as the III key 32, or it can be obtained from this key. Record The encrypted session key is individually transmitted to the television for each distribution key 41 used. sent on the data channel by the transmission sender.

The distribution key 41 is fixed for a long time and is kept hidden from the subscribers. . One such method of keeping the keys secret is also block 4. 3, which performs the decryption of the session key, as indicated by reference number 42. integrated circuits such as custom-made integrated circuits. Distribution key digital The bit pattern should also be long enough to prevent discovery by an expensive search. made in The encoded session key is sent to block 43 by the distribution key. The data channel is decoded by the Both are applied to block 44. The descrambling code is then deciphered. is decrypted in block 44 by the session key that was 45, the analog color component of the television signal as shown in block 46; The audio portion of the television signal as shown and the digital portion as shown in block 47. of other signals such as other signals at the receiver that require scrambling or decoding. Can be used for descrambling or decoding and provides decoding and decoding.

FIG. 5 is yet another embodiment of the invention relating to decoding at the receiving end. Fourth The same reference numbers are used to identify corresponding elements shown in the figures. This embodiment Similarly, the key code is the decrypted session key from block 43 as described above. is decoded at block 44 using .

Another embodiment of the invention for decoding on the receiver side is shown in FIG. Book In an embodiment, a unique encoded session key is sent to all users. is obtained from the specified key and subscriber code C. Block 50 is a symbol encoded session key and encoded video descrambling code ′ represents the received digital data channel of the television signal containing . The encoded session key is provided to block 54, where the fixed key K is kept secret. The subscriber code C from block 51 is also unique for each subscriber. The information is manually entered by the subscriber. The only advantage of this system is Only the encoded session key needs to be transmitted. Therefore, Tushion key is easy and good. Furthermore, the distribution key D updates the manual input code C. This allows changes to be made at less frequent intervals. Distribution key D is 52 from the fixed key and subscriber code C. Symbolized The distribution key D is thus obtained in block 5.4. along with the decoded and encoded descrambling code from the data channel. for block 55. The descrambling code is then decoded. is decrypted in block 55 by the session key obtained, and then in block 56 ．． Descrambling or unpacking the signal at the receiver as indicated by 57.58 It can be used for reading.

A further embodiment of the invention regarding decoding at the receiving end is shown in FIG. . This embodiment eliminates the need for manual entry of codes by subscribers and This eliminates the existence of a common distribution key for In this embodiment, the trust The session key encodes the data channel of the signal, and the decoder address immediately. Unique authentication code based on serial number and encoded descrambling code Including de. The session key is decrypted by the distributed key from block 6I. is given for block 62. This decrypted encoding key is then block 64, where a unique 32-bit internal authentication code is set. is given based on the version key and decoder address or sequence number. obtained The authentication code sent is compared to the authentication code sent to the data channel, and if this If the two match, a logic signal is provided to AND gate 66. AND gate 6 6, the resulting internal authentication code matches the authentication code sent to the data channel The decrypted session key from block 62 passes through block 67 only when allow me to pass. The session key then decodes the descrambling code. can be used by block 67.

In the embodiment shown in FIG. 7, each session is 30 seconds in duration. , during this period each decoder decrypts the session key for the next session. Ru. This session key is the reference number 62 in Figure 7, which is very difficult to copy. is obtained in a custom-made integrated circuit as shown in FIG. At that time the data channel session in use for decoding video descrambling codes in The key also contains a sufficient number of received authorization codes (sufficient for obtaining internal authorization codes). given for. A session key can be used to access a particular television channel. Approximately some time during the last 7 hours of use, the authorization code was not received. For example, it is released from the custom Ic.

The authentication code (including error correction bits) consists of a 39-bit word; 1 are sent on the 250K b/s channel. As a result, 20.000, 000 recipients can be addressed within a 52 minute period. over a period of 7 hours Therefore, each decoder recognizes eight individual cases with one error-corrected code. It will be proven. BER of 1O-2 (bit error rate = (bit erro r rate)), failure for each attempt occurs with probability 0,044. Ru. The probability that all 8 attempts fail is 1.4X 1O-1l (MTBF (Mean time between failures) = MEAN TIME BETWEEN FAILURE S: 100.000,000 years).

The big advantage of authentication codes is that (unlike session keys) these codes Very frequent and inaccurate receipts without affecting service to customers , the address cycle time is 26 minutes.

If most decoders were operating at lo-3 BER, then the decoder 99.95% of readers are authenticated within the normal transmission time of a typical TV program It turns out.

In the embodiment shown in FIG. 7, the television receiver is Must automatically switch between commonly used channels to collect authentication codes. No. However, the count of sessions (since last authentication) or the non-volatile memory (in the maintenance IC) and at least one The 7-hour limit can be extended to an arbitrary maximum to ensure a 2-minute duration rate. I'll come. Furthermore, the receiver will not be used when only one hour of authentication remains (because of its counter). message requesting time or standby mode (teletics display). ) can also be issued. Finally, at the end of this 7 hour period, the receiver There is no need to completely cut off the service, i.e. stop descrambling the signal. It then begins a period of service reduction, starting with, for example, a few hours of monochrome reception.

Facilitate the use of ensuring payment of subscription fees and/or receipt of authorization codes; Collect the necessary evidence for various windows, and only take action when you have sufficient evidence. We should act rationally.

In the embodiment shown in FIG. (or immediately if in standby mode), the maintenance device prepares the space for the next session. acquisition of the session key occurs independently. Another time to release the key unconditionally It would be possible to design roads.

There are security devices that are very difficult to duplicate, but are designed to provide a potential key. The device that was accessed has the distribution key D (probably obtained by breaking one of the security devices). ) must be used. If a rogue receiver in possession of a particular distribution key If found, the corresponding session key encoding is Condition of leaving at least one key (D) that can decrypt the session key The key distribution channel may also be removed. This is out of 3,000 Can be configured by providing four selected keys to each decoder However, no two decoders hit the same set of four keys. :l, 000? There are 3.3×10'2 ways to select four different keys from the list. degree ) can be eliminated by leaving one of them operational. if If the second decoder is copied, all copies can be done at a cost of 7 Ru. In this way up to 10 decoders can be eliminated. After that, no more This exclusion will cause some legitimate decoders to become inactive. These de Coders (and the customers who own them) make predictions via software at the sender. can do.

2! Simultaneously disable all copies of 20 different decoders in the broadcast area of This requires replacing only 10 legal decoders.

FIG. 8 shows an example of a decoder that can be used to implement the present invention. A block diagram is shown. Further examples of such decoders are included for reference. U.S. patent application filed June 24, 1983, assigned to the same assignee cited in the text. Described in patent application No. 507.5654 "Encoding and decoding of video signals" ing.

As shown in Figure 8, the scrambled MAC television signal is first from this signal to the multiplexer 300, which outputs the luminance signal and chrominance signals (i.e. color components) and acoustic, synchronization, timing and Separate teletics information. The luminance signal is transmitted to the CCD rack where this signal is decompressed. in-store to the luminance store 302 and then to the low-pass filter 304. It is sent and filtered here. The analog luminance signal is then sent to the output interface. Proceed to base 306. The sampling signal required to decompress the luminance is clock driver 310 and two clock drivers 310. Store 302 is provided.

The chrominance signal from demultiplexer 300 is also sent to chrominance store 3. 12, this store is also a CCD line store. . Two color differences whose separate outputs are filtered in two low-pass filters signal and then to output interface 306. need A sampled signal is sent to three clock pulses from timing generator 308. It is provided to a chrominance store 312 via a driver 310.

Signals that do not constitute luminance or chrominance are also passed through demultiplexer 300. is separated from the MAC television signal. These signals include acoustics, teletics and synchronization signals, which are filtered through one of two low-pass filters 318. Fixed frequency timing information is sent to multiplexer 316, but the fixed frequency timing information is sent to multiplexer 316. The signal is sent to the demultiplexer 316 via the data processor 320 .

The demultiplexer 316 separates these 18 signals and audio demultiplexes the audio signal. plexer 322 and synchronization and timing signals to the clock and synchronization recovery circuit. 324 and timing generator 308. Demultiplexer 315 The acoustic information from is separated into four channels in an acoustic demultiplexer 322 and output by analog audio processor 326.

Teletic information is transferred to character Send it to Nerator 328.

The operation of the decoder is under the control of a microprocessor 330, which Clock and synchronization recovery circuit 324 on bidirectional bus 334, 336, 338 , communication status with teletic character generator 328 and RAM 332 It is in.

Output interface 306 provides teletics from character generator 326. The brightness signal is sent from the low-pass filter 304, and the brightness signal is sent from the low-pass filter 31. 4 and the timing signal from timing generator 308. Receive a signal. Its output is standard for display in a television receiver. This is an NTSC color television signal.

The present invention has been described herein in terms of preferred embodiments. But these The embodiments are merely examples, and the invention is not limited thereto. person skilled in the art Upon reading this specification, it will be understood that within the scope of the invention as defined by the copulatory claims. It will be understood that many changes and modifications are possible.

Engraving (no changes to the content) FIG, I FIG. 2 Engraving (contents (no changes)) Engraving (no changes to the content) Engraving (no changes to the content) Engraving (no changes to the content) Engraving (no changes to the content) Written amendment Cj5 September 11, 1986 Mr. Kunio Kogawa, Commissioner of the Patent Office, Record 1, Indication of the incident PCT/US86100801 , name of invention Method and apparatus for scrambling and descrambling television signals 3. Person who makes corrections Relationship to the incident: Applicant address Name: Scientific Atlanta Address: 2-chome Otemachi, Chiyoda-ku, Tokyo 2-1 Shin-Otemachi Building Room 206 5. Date of amendment order: August 25, 1986 (transmission date) 6. Subject of amendment international search report

Claims (37)

[Claims] 1. A device for encoding information descrambles and/or codes for decoding. At the location, a first encoding key device for producing a first encoding key; a second encoding key device for producing a second encoding key; a first encoding key for encoding the second encoding key according to the first encoding key; an encoding device and a second encoding device for encoding the code according to the second encoding key; a second encoding device, said encoded second encoding key and said notation; The encoded code serves to descramble and/or decode said information. A device characterized in that it is provided for. 2. characterized in that said information is an intelligence part of a television signal An apparatus according to claim 1. 3. the code is a desk of the intelligence portion of the television signal; characterized by containing multiple keys for performing rumple and/or decryption; 2. The device according to claim 2. 4. the encoded second encoding key and the encoded code; Further providing a transmission device for transmitting the revision signal to the receiver receiving the revision signal. 3. The device according to claim 2, characterized in that: 5. The transmitting device is a television transmitter that transmits the television signal. 5. The device according to claim 4, characterized in that: 6. 2. The method according to claim 1, wherein the code is changed periodically. Device. 7. Claim 1, characterized in that the first encoding key is changed periodically. The device according to item 1. 8. Decoding and decoding the code for information descramble and/or deciphering said In the apparatus in which the code is encoded according to the encoded first encoding key, a decryption key device for providing a decryption key of 1; and a decryption key device for providing a decryption key of 1; a first decryption device for decrypting the encrypted encoding key; to said encoding key for descrambling and/or decoding said information. Therefore, a second decoding device for decoding the code is provided. Device. 9. characterized in that said information is an intelligence part of a television signal 9. The apparatus according to claim 8. 10. the code deselects the intelligence portion of the television signal; characterized by containing multiple keys for crumple and/or decryption; The apparatus according to claim 9. 11. encode a code for descrambling and/or decoding information; and a system for decoding the code, a first encoding key device for producing a first encoding key; a second encoding key device for producing a second encoding key; a first encoding key for encoding the second encoding key according to the first encoding key; an encoding device and a second encoding device for encoding the code according to the second encoding key; 2 symbolizing device; a first decryption key device for generating a first decryption key; for decrypting said encoded second encoding key according to said first decryption key; a first decoding device for descrambling and/or decoding said information; , a second decryption device for decrypting the code according to the second decryption key. A system characterized by having 12. characterized in that said information is an intelligence part of a television signal; 12. The apparatus according to claim 11. 13. the code deselects the intelligence portion of the television signal; characterized by containing multiple keys for crumple and/or decryption; 13. The apparatus according to claim 12. 14. the encoded second encoding key and the encoded code; Further, a transmitting device for transmitting the television signal to the receiver receiving the television signal may be provided. 13. The device according to claim 12, characterized in that: 15. The transmission device is a television transmitter that transmits the television signal. 15. Apparatus according to claim 14, characterized in that: 16. Claim 11, characterized in that the code is changed periodically. equipment. 17. Claims characterized in that the first encoding key is changed periodically. Apparatus according to clause 11. 18. How to descramble information and/or encode codes for decoding. In law, providing a first encoding key; providing a second encoding key; encoding the second encoding key according to the first encoding key; encoding the code according to the second encoding key; The encoded second encoding key and the encoded code are used to decode the information. A method characterized in that it is provided for scrambling and/or decoding. 19. the encoded second encoding key and the encoded code; further comprising the step of transmitting the television signal to a receiver that receives the television signal. 19. The method of claim 18, characterized in that: 20. Claim further comprising the step of periodically changing the code. The method according to item 18. 21. The method further comprises the step of periodically changing the first encoding key. 19. The method according to claim 18. 22. the information encoded according to the first encoding key in which the code is encoded; In the method of deciphering the code for crumple and/or deciphering, deciphering provide the key, decrypting the encoded first encoding key according to the first decryption key; to the first encoding key for descrambling and/or decoding the information; deciphering said code. 23. For each line, the first period in which video information exists and the first period in which video information exists. Scraping a type of line-scanned television signal with a second period of time absent; In the method of performing descrambling and descrambling, the video information is Scramble according to Rumple Code, To descramble the scrambled video information, provide the scrample code, encoding a descrambling code of the video according to a first encoding key; session to decipher the descramble code of the encoded video. - providing a key and encoding the session key according to a second encoding key; During the second period when no video information is present, the encoded video desk The Rumple code and said encoded session key are sent to said television signal. Included in the issue, providing a distribution key at a receiver receiving the television signal; given for said encrypted session key and given for said decrypted session key. This key is used to decode the encoded video descrambling code. The descramble code of said decrypted video is used for said Scrambler. A method characterized in that it is used for descrambling of sampled video information. Law. 24. said step of providing a session key from said first encoded key; Claim 1, further comprising the step of obtaining the session key. The method described in Section 23. 25. the step of providing a distribution key at the receiver includes the second symbol Claims characterized in that the method includes the step of obtaining the distribution key from a distribution key. The method described in paragraph 1. 26. said step of providing at least one session key providing a unique session key for each of said receivers receiving the vision signal; 24. The method of claim 23, comprising the step of providing. 27. said step of providing a distribution key for each of said unique session keys; Claim 4 comprising the step of providing one distribution key for each The method described in section. 28. The session key and the distribution key are periodically changed. The method according to claim 1. 29. For each line, the first period in which video information exists and the first period in which video information exists. Scraping a type of line-scanned television signal with a second period of time absent; In the method of performing unscrambling and unscrambling, the video information is Scramble according to the Crumple Code, To descramble the scrambled video information, provide the scrample code, encoding a descrambling code of the video according to a first encoding key; session to decipher the descramble code of the encoded video. - providing a key and encoding the session key according to a second encoding key; During the second period when no video information is present, the encoded video desk The Rumple code and said encoded session key are sent to said television signal. Included in the issue, A subscriber code and a fixed key in the receiver receiving said television signal. and the subscriber code and said fixed key are used to obtain the distribution key. and the distribution key is used to decrypt the encoded session key. and said decrypted session key is sent to said encoded video desk. Descram of the decoded video used to decode the Rumple Code The pull code is used to descramble the previously scrambled video information. A method characterized in that it is used. 30. said step of providing a session key from said first encoded key; Claim 1, further comprising the step of obtaining the session key. The method according to item 29. 31. Claims characterized in that the session key is changed periodically. The method according to paragraph 29. 32. said step of providing a subscriber code and a fixed key to said television program; a station providing one unique subscriber code for each said receiver receiving a subscription signal; 30. The method of claim 29, further comprising the steps of: 33. For each line, the first period in which video information exists and the first period in which video information exists. Scraping a type of line-scanned television signal with a second period of time absent; In the method of performing unscrambling and unscrambling, the video information is Scramble according to the Crumple Code, To descramble the scrambled video information, provide the scrample code, encoding a descrambling code of the video according to a first encoding key; providing a plurality of authentication codes, each of the plurality of authentication codes is unique for each receiver receiving the encoding the session key according to a second encoding key; During the second period when no video information is present, the encoded video desk Rumple code, said encoded session key, and said plurality of authentications. Send the code and a distribution key is provided at a receiver receiving the television signal, the distribution key being provided for the decryption of said encoded session key and said decrypted session key. The application key is used within each receiver to obtain an internal authentication code and is The authentication code obtained within the above is compared with the plurality of authentication codes, and the authentication code is The comparator displays a logic signal when a match is found, and the logic signal is The decrypted session key is the encoded video descrambler. Enable a logic device to allow the code to be decoded, and The descramble code for the scrambled video is A method characterized in that it is used for descrambling. 34. Setup to decipher the descramble code of the encoded video. the step of providing a session key from the first encoding key; Claim 33, characterized in that the method further comprises the step of obtaining a configuration key. the method of. 35. the step of providing a distribution key at the receiver includes the step of providing a distribution key at the receiver; Claim 33, further comprising the step of obtaining the distribution key from The method described in section. 36. The step of providing a distribution key at the receiver is performed for each of the receivers. providing a distribution key that matches said unique session key. 34. A method according to claim 33, characterized in that: 37. The session key and the distribution key are periodically changed. 34. The method according to claim 33.