Scramble system for prevention illegal user

Abstract: A scramble system can effectively prevent a scrambled broadcast from being viewed illegally. In a scramble system in which a video signal scrambled by a scrambling apparatus (10) is descrambled by a decoding apparatus (20), an identification code that specifies the decoding apparatus (20) is inserted into a vertical blanking period of the video signal supplied to the decoding apparatus (20).

Description: The present invention relates to a scramble system for use with a television signal transmitted in the form of a scrambled signal. In television broadcasting, there is now commercially available scrambled broadcasting by which only particular reception contract viewers are permitted to enjoy a video program. In this scrambled broadcasting, a television broadcast signal is transmitted from a broadcasting station as, for example, a signal that is scrambled such that a normal picture cannot be reproduced by an ordinary television receiver. Then, a decoding apparatus for descrambling the scrambled broadcasting wave is distributed to only contractors who pay charges according to a predetermined method. Such viewers can then enjoy normal picture and sound by connecting the decoding apparatus to the receiving apparatus. However, in pay channel television broadcasting using the scrambled broadcasting system, it is frequently observed that a video program is illegally enjoyed by the viewer by abusing the decoding apparatus. In ordinary pay channel broadcasting, the contractor is permitted to view only the received television broadcasting by the television receiver or only to record such television broadcasting by a viewer's VTR. Accordingly, it is illegal that a video tape in which the received television broadcasting is recorded is distributed or a television broadcasting is received outside the contracted service area. Further, it is also illegal that the television broadcasting is viewed at a place where many people can watch television broadcasting such as a hotel or the like although the viewer made the contract for only personal use in the home. According to the conventional scrambled broadcasting, if the decoding apparatus is so effective, then it is impossible to avoid such illegal viewing. Further, when a pirated video tape in which the scrambled broadcasting is recorded is distributed in the market, it is impossible to discover which decoding apparatus formed the pirated video tape. Therefore, it is an object of the present invention to provide an improved scramble system in which the aforesaid shortcomings and disadvantages of the prior art can be eliminated. WO-A-82/01273 discloses a video signal scrambling system comprising: a program transmitting apparatus for outputting a video program; a scrambling apparatus for scrambling said video signal together with an audio signal; and a decoding apparatus for processing the video signal from the receiving apparatus, wherein the decoding apparatus is adapted to insert an identification code of said decoding apparatus into a demodulated video signal. WO-A-82/01273 is primarily concerned with a video disc rental system (wherein the scrambling apparatus scrambles the signal recorded into a video disc and then the decoding apparatus is provided in the renter's apparatus), also discloses that the system is useful for a TV system having a transmitter and receiver. US-A-4,914,694 discloses a number of ways of modifying a television signal before broadcast, in order to inhibit unauthorised reproduction of the signal after reception. EP-A-0,267,039 discloses a system which receives and decodes scrambled (of "encrypted") TV broadcast signals with which an additional code is also broadcast. The additional code is interpreted by the receiver either to forbid or to allow taping of the received programme. The receiver includes "anti-taping" circuitry which processes the received signal when taping is forbidden to embed a signal which introduces distortion into any copies made, and the receiver also includes "copy protection" circuitry which formats the recorded program when taping is allowed to induce distortion in any duplicate copy. According to an aspect of the present invention, there is provided a video signal scrambling system comprising: a program transmitting apparatus for outputting a video program and soft information concerning said video program; a scrambling apparatus for scrambling said video signal together with an audio signal; a transmitting apparatus for transmitting a signal supplied from said scrambling apparatus; a receiving apparatus for receiving and demodulating said signal transmitted from said transmitting apparatus; a decoding apparatus for processing the video signal from the receiving apparatus; and video equipment to which a signal from said decoding apparatus is supplied, wherein the scrambling apparatus is adapted to insert said soft information into a vertical blanking period of a video signal output from said transmitting apparatus, the decoding apparatus is adapted to insert an identification code of said decoding apparatus into a vertical blanking period of a video signal demodulated from said receiving apparatus, and the system further comprises an information detecting apparatus for detecting said identification code and said soft information inserted into said predetermined line within the vertical blanking period of said video signal and for determining therefrom whether the viewer is viewing illegally. Thus a scrambled broadcast can be prevented from being viewed illegally and the viewer can watch a video program satisfactorily even when the identification code is inserted into a video signal. Nevertheless a video decoding apparatus can be identified. The present invention will be further described by way of example in the following detailed description of an illustrative embodiment thereof, in conjunction with the accompanying drawings, in which: FIG. 1 is a block diagram showing a circuit arrangement of a scramble system which includes only some of the features of claim 1, but is useful for understanding the invention; FIGS. 2A to 2C are diagrams of waveforms of a video signal showing the condition that soft information and an identification code are superimposed upon the video signal, respectively; FIG. 3 is a block diagram showing a circuit arrangement of the scramble system according to an embodiment of the present invention; and FIG. 4 is a block diagram showing a circuit arrangement of the scramble system which includes only some of the features of claim 1, but is useful for understanding the invention. As shown in FIG. 1 a scramble system, which includes only some of the features of claim 1 but is useful for understanding the invention, is provided a program transmitting apparatus 1 from which there are transmitted a variety of video programs as a video signal and an audio signal. Simultaneously, the program transmitting apparatus 1 transmits soft information concerning a video program now transmitted, such as identification information for identifying a video program transmitting source, contents of soft and a transmission date, etc. As the soft information, there is used data that is coded by a predetermined method. The video signal, the audio signal and the soft information transmitted from the program transmitting apparatus 1 are supplied to a scrambling apparatus 10. In the scrambling apparatus 10, the video signal and the soft information supplied thereto from the program transmitting apparatus 1 are supplied to a multiplexing (MUX.) unit 11, in which a coded soft information is inserted into a predetermined one horizontal line within the vertical blanking period of the video signal. More specifically, let it be assumed that a video signal having a vertical blanking period as shown in FIG. 2A, for example, is output from the program transmitting apparatus 1. Then, at that time, soft information d1 is superimposed upon a predetermined horizontal line within the vertical blanking period as shown in FIG. 2B. The horizontal line on which the soft information d1 is superimposed is located outside of a vertical synchronizing (sync.) period so that the horizontal line cannot affect the vertical sync. processing. The video signal output from the multiplexing unit 11 within the scrambling apparatus 10 and the audio signal supplied from the program transmitting apparatus 1 are supplied to a scramble processing unit 12, in which the video signal and the audio signal are processed in a predetermined scramble processing fashion. In the scramble processing, the video signal, for example, is scrambled by a line-rotation system or line-permutation system. The audio signal is scrambled by an addition of pseudo-random sequence (in the case of a digital audio signal). Video and audio signals thus scrambled are supplied to a transmitting apparatus 3 from the scrambling apparatus 10. The transmitting apparatus 3 multiplexes the audio signal and management information supplied thereto and transmits the multiplexed audio signal and management information and the video signal according to a predetermined transmission method. When a satellite broadcast is carried out by utilizing a broadcast satellite, for example, the multiplexed audio signal and management information and the video signal are modulated to a satellite broadcast transmission channel signal and then transmitted to the broadcast satellite. A circuit arrangement of a receiving side that receives the television broadcast thus transmitted will be described next. As shown in FIG. 1, there is provided a receiving apparatus 4 that receives a broadcast wave, i.e., a television broadcast wave transmitted from the transmitting apparatus 3. When a satellite broadcast signal, for example, is received, the receiving apparatus 4 demodulates a broadcast wave received at a parabolic antenna (not shown) to provide baseband video and audio signals and also extracts management information multiplexed on the audio signal. The receiving apparatus 4 supplies the video and audio signals thus demodulated to a decoding apparatus 20. In this arrangement, the video signal supplied to the decoding apparatus 20 is supplied to a multiplexing unit 21, in which an identification code is inserted into a predetermined one horizontal line within the vertical blanking period of the video signal, i.e., an identification code d2 is superimposed upon a predetermined horizontal line within the vertical blanking period of the video signal as shown in FIG. 2C. This identification code d2 might be a code of an individual number assigned to each of decoding apparatus. The individual number code information is stored in a decoding condition memory unit 25 and the individual number code information stored in the decoding condition memory unit 25 is supplied to the multiplexing unit 21. The horizontal line upon which the identification code d2 is superimposed is made adjacent to the horizontal line upon which the soft information d1 is superimposed and is prevented from affecting the vertical synchronizing processing. The video signal on which the identification code d2 is superimposed by the multiplexing unit 21 and the audio signal received by the receiving apparatus 4 are supplied to a decode processing unit 22 in which the descramble processing for descrambling the scramble is carried out. The descramble processing in this case is executed when information becomes coincident with the decoding condition. More specifically, the management information received by the receiving apparatus 4 is supplied to a decode processing unit 23, in which it is descrambled. The management information thus descrambled is supplied to a decoding condition setting unit 24. The decoding condition setting unit 24 obtains information concerning the decoding condition set in the decoding apparatus 20 from the decoding condition memory unit 25 and determines whether or not management information contained in the received broadcast wave is coincident with the decoding condition set in the decoding apparatus 20. If the management information is coincident with the decoding condition, then the descrambling processing in the decode processing unit 22 is permitted. The video and audio signals thus descrambled by the decode processing unit 22 are output from the decoding apparatus 20. The video and audio signals output from the decoding apparatus 20 are supplied to a video equipment. When a television receiver 31 and a video tape recorder (VTR) 32 are installed, the video and audio signals are supplied to the television receiver 31 and the VTR 32, respectively. If the receiving side is community receiving facilities of relatively small scale, then the video and audio signals output from the decoding apparatus 20 are supplied to a retransmissions apparatus 33 and then retransmitted from the retransmissions apparatus 33 via a wire system or wireless system, thereby being received at a plurality of television receivers (terminal apparatus 36). FIG. 3 shows an embodiment of the scramble system according to the present invention. In FIG. 3, like parts corresponding to those of FIG. 1 are marked with the same references and therefore need not be described in detail. In this embodiment shown in FIG. 3, the processing required by the broadcasting station side to manage the viewer contract is executed by a management apparatus 2 formed of a computer. The management apparatus 2 supplies the scrambling apparatus 10 with information required to manage each terminal equipment (decoding apparatus). A scramble processing unit 13 provided within the scrambling apparatus 10 scrambles the information necessary for the management and supplies the management information thus scrambled to the transmitting apparatus 3. In the embodiment of the present invention, as shown in FIG. 3, an information detecting apparatus 5 is prepared by the management side that manages the television broadcast reception contract. The information detecting apparatus 5 detects the identification code d2 and the soft information dl inserted into the predetermined horizontal lines in the vertical blanking period of the video signal. When it is determined that there is an illegal viewer, a video signal output from the decoding apparatus 20 of the illegal viewer is supplied to the information detecting apparatus 5 which then detects the identification code. The identification code is detected by the information detecting apparatus 5 as described above, whereby the viewer who makes the reception contract to utilize the decoding apparatus to which the detected identification code number is assigned can be judged by the management side. Then, if management information that inhibits the decoding apparatus of the illegal viewer from effecting the descrambling is multiplexed on the broadcast wave and then transmitted, then the decoding apparatus of the illegal viewer is inhibited from executing the descramble processing. Therefore, the illegal viewer cannot watch the pay television broadcast. Alternatively, it is possible to warn the illegal viewer having the decoding apparatus by some proper means. According to this embodiment, the aforesaid control operation can be carried out. Therefore, let it be assumed that there is a pay channel television broadcast that the viewers can make reception contract within a certain service area, for example. Also, let it be assumed that a hotel outside the service area (or hotel within the service area and which is not permitted to receive the pay channel television broadcast) gives its service to guests so that such pay channel television broadcast received is descrambled by the decoding apparatus and can be received by the television receiver in each guest room. At that time, a video signal supplied to the television receiver in any quest room is supplied to the information detecting apparatus 5 to thereby judge the decoding apparatus thus utilized to descramble the pay channel television broadcast. Thus, the decoding apparatus that is illegally utilized can be specified with ease by the information detecting apparatus 5 when it is set in the doubtful place where illegal reception is assumed to be carried out. In this case, because the identification code is inserted into the vertical blanking period, ordinary received picture and received sound are not changed at all and the viewer can enjoy the pay channel television broadcasting without trouble. When there is a so-called pirated video soft that is formed from a video tape 34 in which a television broadcast received by the reception system of this embodiment is recorded by the VTR1 32, such pirated video soft is bought, reproduced by a VTR2 35 and then an identification code inserted into the vertical blanking period of the reproduced video signal is detected by the information detecting apparatus 5, whereby the decoding apparatus that was utilized in making the pirated video soft can be determined. In this case, when the video program is transmitted, by detecting the soft information inserted into the vertical blanking period by the information detecting apparatus 5 in the scrambling apparatus 10 side, it is convenient that time and date of television broadcasting that makes the video soft can be determined. While the identification code is inserted into one horizontal line as described above, the present invention is not limited thereto and the identification code may be inserted over a plurality of horizontal lines. Further, such a variant is also possible that a set of identification codes can be detected by a combination of data inserted into horizontal lines of the vertical blanking periods of a plurality of fields. Furthermore, the identification code may not be inserted into each field but may be cyclically inserted into every plural fields. While the identification code is inserted before the descramble processing is executed by the decode processing unit 22 of the decoding apparatus 20, the present invention is not limited thereto and such a variant as shown in FIG. 4 is also possible. That is, FIG. 4 shows a scramble system which includes only some of the features of claim 1, but is useful for understanding the invention. As shown in FIG. 4, the identification code may be inserted into the video signal processed by the decode processing unit 22. Further, the soft information may be inserted into the video signal in the scrambling apparatus 10 after the scrambling processing was executed. Because the video signal in the vertical blanking period is not scrambled in the ordinary scramble processing, the inserted condition of the identification code is not affected. The soft information concerning the video program now being transmitted is inserted into the video signal by a processing similar to that of the identification code in the scrambling apparatus 10 as described above so that the contents of the video program being transmitted can automatically be detected on the receiving side by detecting the soft information on the reception side. According to the present invention, the decoding apparatus utilized can be specified by detecting the identification code inserted into the video signal when the video and audio signals are descrambled by the decoding apparatus. Therefore, when there is an illegal viewer, the decoding apparatus used by the illegal viewer can be detected. In this case, since the identification code is inserted into the vertical blanking period, general users cannot know the identification code at all and the insertion of the identification code cannot hinder the legal viewers from watching the video program satisfactorily. Further, because the code concerning the soft information is inserted into the video signal, the soft information also can be detected when the identification code is detected. Therefore, if a video soft in which a scrambled broadcasting is recorded, for example, is commercially available on the market, the soft information is detected from the video soft together with the identification code, thereby making it possible to specify a video transmission side. Having described a preferred embodiment of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiment and that various changes and modifications could be effected therein by one skilled in the art without departing from the scope of the invention as defined in the appended claims.

Claims: A video signal scrambling system comprising: a program transmitting apparatus (1) for outputting a video program and soft information concerning said video program; a scrambling apparatus (10) for scrambling a video signal together with an audio signal; a transmitting apparatus (3) for transmitting a signal supplied from said scrambling apparatus (10); a receiving apparatus (4) for receiving and demodulating said signal transmitted from said transmitting apparatus (3); a decoding apparatus (20) for processing the video signal from the receiving apparatus (4); and video equipment (31-33) to which a signal from said decoding apparatus is supplied, wherein the scrambling apparatus is adapted to insert said soft information into a vertical blanking period of a video signal output from said transmitting apparatus (1), the decoding apparatus (20) is adapted to insert an identification code of said decoding apparatus into a vertical blanking period of a video signal demodulated from said receiving apparatus (4), and the system further comprises an information detecting apparatus (5) for detecting said identification code and said soft information inserted into said predetermined line within the vertical blanking period of said video signal and for determining therefrom whether the viewer is viewing illegally. A scrambling system according to claim 1, wherein said scrambling apparatus (10) is adapted to superimpose said soft information upon a predetermined horizontal line within a vertical blanking period of said video signal supplied from said program transmitting apparatus (1). A scrambling system according to either one of the preceding claims, wherein said decoding apparatus (20) is adapted to superimpose said identification code of said decoding apparatus (20) upon a predetermined horizontal line within the vertical blanking period of said video signal. A scrambling system according to any one of the preceding claims, further comprising a management apparatus (2) for supplying said scrambling apparatus (10) with management information necessary for managing each of said decoding apparatus (20). A scramble system according to claim 4, further comprising a scrambling means (13) for scrambling information necessary for managing each of said decoding apparatus (20) and supplying the scrambled management information to said transmitting apparatus (3) . A scramble system according to any one of the preceding claims, wherein said soft information contains an identification code for identifying the video program transmission side. The scramble system according to any one of the preceding claims, wherein said soft information contains a video program transmission time and date.

Inventors: IHARA KIICHI, IHARA, KIICHI, Ihara, Kiichi, c/o Sony Corporation
Applicants: SONY CORP, SONY CORPORATION
Application year: 1993
Main classification: H04N7
IPC codes: H04N7, H04K1