CN1141559A - Secrecy broadcasting system - Google Patents

Abstract

The invention discloses an encrypted broadcasting system which is characterized in that even the same information data have different results after encryption processing. The invention comprises an encryption processor which appends a first lengthy data to the information data, then produces a first appended lengthy data, appends a second lengthy data to the first appended lengthy data and produces a second appended lengthy data, and conducts designated cipher processing to the second appended lengthy data, and a decoding device to a judgment device which judges whether the above operation and processing are right according to the restored second appended lengthy data so as to estimate correctness of the information data.

Description

Secrecy broadcasting system

The present invention relates to for example such user's television broadcasting system such as CATV (cable TV) broadcast system and broadcasting-satellite system, particularly relate to the improvement of the data of this broadcasting being carried out sending, being decrypted at receiving terminal after the encryption secrecy broadcasting system of processing.

As is generally known, for above-mentioned secrecy broadcasting system, receiving terminal from TV station to each user not only carries out sending after the encryption to the TV signal that comprises picture signal and voice signal, and also must carry out sending after the encryption to the control information that is used to control receiving terminal.

At this moment, in the encryption that formerly has, the at first corresponding information data that transmits is carried out tediously long property additional treatments, carries out the encryption by the 1st time and the 2nd time processed constitutes then.For example, establish information data and be " 83 ",, carry out tediously long property additional treatments, thereby generate the tediously long property additional data that is expressed as " 8323 " the fixing tediously long property data " 23 " of its affix.

Then, by everybody of this tediously long property additional data " 8323 " added 1 respectively, promptly

8+1＝9

3+1＝4

2+1＝3

3+1=4 generates the 1st processed of the data that are expressed as " 9434 ".

And, with the data " 9434 " after the 1st processed as text, as such shown in 3 (highest orders)～position 0 (lowest order) of the position among Fig. 1, everybody is transformed to 2 system numbers respectively with it, by as among Fig. 1 from position 3 ' (highest order)～position reading in like that shown in 0 ' (lowest order), after being transformed to 16 system numbers, read in from bottom to top, generate the 2nd processed of the password that is expressed as " A258 ", so far, be the data of " A258 " just with information data " 83 " encryption.

In addition, at receiving terminal,,, judge in transmitting the way that data have or not to alter etc. according to whether reproducing additional tediously long property additional data " 23 " by the data that receive are carried out and above-mentioned opposite processing.

But, in above-mentioned existing secrecy broadcasting system, because tediously long property additional data is fixed, the result of identical information data encryption is always become identical data, so, in the process that sends repeatedly, the possibility of being understood has just improved, thereby illegally altered easily etc.

For the send mode of above-mentioned control information, the band inner control that the outer control of the band that utilizes different transmission lines to send TV signal and control information is respectively independently arranged and on TV signal, utilize common transmission line to send the control information superposition.

Wherein, not needing especially independently transmission line because the band inner control is compared with the outer control of band, is practical control, so the possibility of Shi Shiing is very high from now on.Yet in the band inner control, control information is not always to be superimposed on the TV signal of all channels to send.For example, existing control information is superimposed to the channel that sends on the TV signal, also has control information not to be superimposed to channel on the TV signal fully.In addition, even control information is superimposed to the channel that sends on the TV signal, this control information also has situation about sending by certain or irregular batch (-type).

Therefore, the receiving terminal that formerly has is except the user selects not comprise the channel of control information, particularly when the mains switch with receiving terminal disconnects, always receive the channel that comprises control information by automatically being controlled to be, just can obtain up-to-date control information.But, owing to always receive of the most of circuit just always constantly power supply of the state of the channel that comprises control information to receiving terminal, and both uneconomical so power consumption increases, must take some countermeasures to heating again.

One of this user's TV (charge) broadcast system is illustrated in clear and in November, 63 according in the consulting to " about the technical conditions of the charge method of the television broadcasting that utilizes satellite broadcasting " of electrical communication technology review conference consulting (after, be called document 1).

Fig. 2 is the system configuration of the charge method shown in the document 1, as cipher mode, uses PN signal (simulation random noise signal) addition formula.

In this charging broadcast system, be sent to the broadcast singal of decoder 210 from TV station 110, comprise the picture signal and the subsignal of encryption, comprise the digital audio signal of encryption and programme information in the subsignal and about the individual information of decoder 210.

In TV station's 110 1 sides, in the individual information about decoder 210 is among job key Kw, contract content and the decoder ID, use decoder ID from major key file 110g, to obtain major key Kmi, use this major key Kmi, utilize scrambler 110f to carry out the encryption of individual information.In addition, use job key Kw, utilize scrambler 110e to carry out the encryption of the programme information on encryption key Ks, TV station's identification, service, days etc.

Because and this part do not have direct relation, so, the details of cipher mode is not explained.But picture signal and voice signal use the PN signal to encrypt respectively in image encryption device 110a and sound encryption equipment 110b.The PN signal that is used to encrypt is the random data that order changes, and is supplied with by PN generator 110c.The initial condition of PN generator 11c is given by encryption key Ks.

The voice signal of encrypting is with the programme information of the initialized timing information of PN generator 110c, encryption and individual information are become subsignal (sub signal) after by superposer 110d superposition.The picture signal of this subsignal and encryption is exported from TV station 110 as broadcast singal (broadcasting wave).

Broadcast singal is owing to the triple cryptography architecture that has used job key Kw, major key Kmi and encryption key Ks has improved confidentiality.In addition, individual information can also transmit to the decoder 210 of correspondence by telephone line and IC (integrated circuit) card.

In decoder 210, utilize separator 210d from the subsignal of broadcast singal, to isolate voice signal, programme information and individual information.The individual information of separating is used the major key Kmi that gives this decoder in advance, utilizes decoder 210f to decipher and preserve.This decoding just can not correctly be carried out, so the decoder that only has this major key Kmi could be deciphered individual information if not using the identical major key Kmi that uses when encrypting.

Programme information uses the job key Kw in the individual information decipher and to obtain, and utilizes decoder 210e to decipher, and still, at this moment also is the identical job key Kw that uses when encrypting if not using, and just can not correctly decipher programme information.

Deciphering resulting programme information and individual information is like this compared by contract for deed condition comparison circuit 210g respectively.Here, when judging conditions of contract unanimity, in the time of can being decrypted, PN generator 210c just becomes operate condition according to this judgement signal.

PN generator 210c uses the encryption key Ks in the programme information that is obtained by decoder 210e that the PN signal takes place.In image decipher 210a and sound decipher 210b, use this PN signal to utilize add operation etc. to be decrypted.

Only picture signal and voice signal are decrypted needed value and when being value identical when encrypting, just carry out the deciphering and the output of picture signal and voice signal as encryption key Ks.For encryption key Ks is restored, need to use job key Kw, so the decoder that does not have job key Kw just can not obtain correct encryption key Ks.

In addition, can change, send the individual information that comprises job key Kw, only to the decoder supply individual information of looking the hearer of wishing that contract continues from TV station 110 in order to make job key Kw.And, restore in order to make the individual information that comprises job key Kw, need major key Kmi, the decoder that only has this major key Kmi could receive individual information.

Major key Kmi is set at different values to each decoder.This value preestablished when for example dispatching from the factory in factory before decoder arrives in the hand of looking the hearer.

In the code translator that above-mentioned charging broadcast system uses, usually, the password decoding in the decoder is handled and the processing of the comparison of the conditions of contract uses the data handling system of having used microprocessor (after, be called microprocessor system) to carry out.And, the circuit that comprises this microprocessor system can also be made IC-card, thereby can change.Fig. 3 is to use IC-card to carry out that password decoding is handled and the structure example of the decoder of the comparison of the conditions of contract.

The decoder of Fig. 3 has the structure roughly the same with the decoder 210 of Fig. 2, and the microprocessor system that is used to carry out above-mentioned processing is located at IC-card 220.IC-card 220 and decoder body can carry out handshaking by pecker.

And IC-card 220 has the nonvolatile storages such as ROM that are used to store major key Kmi (after, be called major key memory, ID memory) 210j, 210k, and ID comparator 210h is arranged on the decoder body.To be included in ID in the individual information of from the subsignal of broadcast singal, separating and the ID of IC-card 220 compares by ID comparator 210h, when both are consistent, just individual information be supplied with IC-card 220.

Programme information and individual information deciphered (210e, 210f), relatively the conditions of contract (210g) when its term harmonization, are just connected switch 210i, and encryption key Ks is supplied with PN generator 210c.Like this, carry out the selection of individual information, just limit according to the individual information of supplying with IC-card 220 and have only the promisor just can carry out audiovisual.In addition, ID comparator 210h be for to the restricted necessary circuit of the communication data speed of IC-card 220.

Fig. 4 is the structure example of the PN generator 210c shown in the above-mentioned document 1.This PN generator is the combinational circuit example of linear feedback shift register (LFSR) 211a, 211b, 211c and non-linear logic (NF) circuit 212a, 212b, 212c.

Encryption key Ks just reads in LFSR211a～211c in that packing into during commutator pulse of obtaining arranged from the subsignal of broadcast singal, carry out the initialization of PN generator.In encryption key Ks, 13 each registers of supplying with LFSR211a, 11 each registers of supplying with LFSR211b, 8 each registers of supplying with LFSR211c.

As the general structure of LFSR211a～211c, what people knew is the PN symbol that M series takes place as shown in Figure 5.This LFSR by n level shift register 2111 and " different " (EX-OR) circuit 2112 constitute, (1≤k≤n) state of the shift register 2111 of level carries out exclusive-OR operation to order to k, input as elementary shift register 2111 is supplied with, by supplying with shift clock to shift register 2111, state transition takes place.

To LFSR211a～211c supply and voice signal and the synchronous shift clock of picture signal, NF212a～212c is supplied with in the output of each 6 register in the register of LFSR211a～211c respectively.

NF212a～212c uses ROM to constitute, and 6 output utilization certain non-linear logics consistent with its mask graph of LFSR211a～211c are carried out conversion, exports by 1.

Diverter switch 214 is switched NF212a, 212c according to the switching signal of NF212b, supplies with " different " (EX-OR) circuit 213."or" else circuit 213 is supplied with in the output of 1 register of LFSR211a, and its output EX-OR with NF212a or NF212c is defeated by image decipher 210a and sound decipher 210b as connection signal.

The state of LFSR211a～211c moves according to the initial condition of shift clock when supplying with encryption key Ks, and meanwhile, the output of NF212a～212c also changes.Like this, use the PN signal at random that obtains from the state of change at random just can be decrypted.

In addition, in this example, be to use NF212a～212c, still, also have the structure that diverter switch 214 and "or" else circuit 213 use as the PN signal is directly supplied with in each 1 register output of LFSR211a～211c.

But, in the above-mentioned code translator that has earlier, if the content of major key Kmi, decoding algorithm and PN generator has been known that by the third party then the fail safe of system will reduce.Therefore, for example, in the example of Fig. 2, image decipher 210a, sound decipher 210b, PN generator 210c and the microprocessor system that decoder 210 is used must utilize the IC of 1 chip etc. to take some countermeasures.

In addition, as shown in Figure 3, in using the decoder of IC-card 220, owing to supply with encryption key Ks to PN generator 210c from IC-card 220, so, might know the structure of PN generator 210c according to the third party that concerns of encryption key Ks and PN signal.

Therefore, the present invention considers above-mentioned situation and motion, even thereby purpose aims to provide the also different very good secrecy broadcasting systems of performance that can prevent illegal deciphering of the result of identical information data encryption.

In addition, thus the present invention also aims to provide receiving control information and the very good TV signal receiver of the low performance that can suppress to generate heat of power consumption reliably.

In addition, thus the fail safe that the present invention also aims to provide simple in structure, can improve system secrecy can suppress the code translator of the illegal secrecy broadcasting system that uses.

Secrecy broadcasting system of the present invention comprises encryption device and decryption device, and this encryption device has: thus to information data additional in time process and the 1st tediously long property data that change generate the 1st generating apparatus of the 1st tediously long property additional data; Additional the 1st tediously long property additional data that is generated by the 1st generating apparatus is carried out the calculation process of appointment and thereby the 2nd tediously long property data that obtain generate the 2nd generating apparatus of the 2nd tediously long property additional data; With the encryption apparatus that the 2nd tediously long property additional data that is generated by the 2nd generating apparatus is carried out the cryptographic processing of appointment; Thereby this decryption device has deciphering the restoring means that restores the 2nd tediously long property additional data from the code data of encryption apparatus output; Thereby with judge calculation process that the 2nd generating apparatus carries out the 2nd tediously long property additional data that is restored by this restoring means and whether set up the judgment means of the correctness of judging the information data of removing the 1st and the 2nd tediously long property data.

According to said structure, to the information data affix in time process and thereby the 1st tediously long property data that change generate the 1st tediously long property additional data, simultaneously, additional the 1st tediously long property additional data is carried out the calculation process of appointment and the 2nd tediously long property data that obtain, generate the 2nd tediously long property additional data, the 2nd tediously long property additional data is encrypted, so, even the result of identical information data encryption is also different, thereby can prevent illegal deciphering.

TV signal receiver of the present invention has received superposition and has been used to control the TV signal of the control information of receiving terminal, is object with the situation according to the control information control action of superposition on this TV signal.And, have and selecting the control information superposition under the state that mains switch disconnects at the channel selecting device of the channel on the TV signal and the control device that cut-out is supplied with the electric power of channel selecting device under the state that obtains control information from the channel of being selected by this channel selecting device.

According to said structure, under the state that mains switch disconnects, select the channel of control information superposition on TV signal, obtaining from selected channel under the state of control information, cut-out is supplied with the electric power of channel selecting device, so, receiving control information reliably not only, and power consumption is low, thereby can suppress heating.

In order to solve above-mentioned problem, the present invention uses the PN signal that image and voice signal or one of them are encrypted in TV station, thereby the key information that will be used for understanding this encryption with other sub-information encrypt superposition and and above-mentioned coded signal one be used from broadcasting secrecy broadcasting system and with the encrypted broadcast signals that receives use the PN signal to be decrypted to be transformed to can audiovisual image and the code translator of voice signal, thereby have the encrypted message that is received by receiving terminal is deciphered the decoder of extracting above-mentioned key information and sub-information out, the key information judgment means of the true and false of the key information that judgement is obtained by this decoder, thereby make particular data PN signal generator that above-mentioned PN signal formation logic can change according to modification information and the sub-information that will obtain take out and change the PN signal formation logic change device of the formation logic of above-mentioned PN signal generator as above-mentioned modification information according to this modification information by above-mentioned decoder when being judged to be by this key information judgment means that true time just carries out state transition from the sequence of states given by above-mentioned key information and generating above-mentioned PN signal from this transition state according to converter logic.

Above-mentioned PN signal formation logic change device is characterised in that: the particular data that is changed arbitrarily by TV station that will be included in the above-mentioned sub-information takes out as modification information.

In addition, the feature of above-mentioned PN signal formation logic change device also is: keep being included in a plurality of particular datas in the above-mentioned sub-information, will be used as modification information by the particular data that is included in the modification information specific data appointment in the above-mentioned sub-information.

Perhaps, the feature of above-mentioned PN signal formation logic change device also is: according to the above-mentioned modification information of area information final decision of this broadcast region of expression.

In the code translator of the secrecy broadcasting system of said structure, can be according to the formation logic of the needed PN signal of the change of the particular data in the sub-information of TV station's supply deciphering, can change the PN signal arbitrarily by TV station, listen with, the fail safe that has improved the confidentiality of system.

Fig. 1 is the figure that is used to illustrate the encryption that has earlier.

Fig. 2 is the circuit block diagram of the structure of expression application charging broadcast of the present invention system.

Fig. 3 is the circuit block diagram of structure of representing the decoder of the secrecy broadcasting system that has earlier.

Fig. 4 is the circuit block diagram of the structure of the PN generator that uses of the decoder of presentation graphs 3.

Fig. 5 is the circuit block diagram of the structure of the LFSR that uses of the PN generator of presentation graphs 4.

Fig. 6 is an embodiment of secrecy broadcasting system of the present invention, is the simple structured flowchart of cable TV (CATV) broadcast system.

Fig. 7 is the figure of control information that is used for the embodiment of key diagram 6.

Fig. 8 is the structured flowchart of details of receiving terminal of the embodiment of presentation graphs 6.

Fig. 9 is the figure of encryption that is used for the embodiment of key diagram 6.

Figure 10 is the flow chart of action of center fixture that is used for the embodiment of key diagram 6.

Figure 11 is the flow chart of action of receiving terminal that is used for the embodiment of key diagram 6.

Figure 12 is the flow chart that is used for other action examples of key diagram 6.

Figure 13 is the flow chart that is used for other action examples of Figure 12 key diagram 6.

Figure 14 is the flow chart that is used for other action examples of key diagram 6.

Figure 15 is the flow chart that is used for the action example of Figure 14 key diagram 6.

Figure 16 is the structured flowchart of details of receiving terminal 17 of the embodiment of presentation graphs 6.

Figure 17 is the flow chart that is used to illustrate the action of Figure 16.

Figure 18 is the routine flow chart of other actions that is used to illustrate Figure 16.

Figure 19 is the routine flow chart of other actions that is used to illustrate Figure 16.

Figure 20 is the routine flow chart of other actions that is used to illustrate Figure 16.

Figure 21 is the routine flow chart of other actions that is used to illustrate Figure 16.

Figure 22 is the routine flow chart of other actions that is used to illustrate Figure 16.

Figure 23 is the routine flow chart of other actions that is used to illustrate Figure 16.

Figure 24 is the flow chart that is used for illustrating with Figure 23 other action examples of Figure 16.

Figure 25 is the routine flow chart of other actions that is used to illustrate Figure 16.

Figure 26 is the routine flow chart of other actions that is used to illustrate Figure 16.

Figure 27 is the circuit block diagram of structure of an embodiment of the code translator of expression secrecy broadcasting system of the present invention.

Figure 28 is the circuit block diagram of concrete structure example of the PN generator 310 of expression Figure 27.

Figure 29 is the circuit block diagram of other structure example of the PN generator 310 of expression Figure 27.

Figure 30 is the circuit block diagram of structure of other embodiment of expression code translator of the present invention.

Figure 31 is the figure of transfer approach of PN modification information that is used to illustrate the PN generator 310 of Figure 30.

Below, the embodiment that present invention will be described in detail with reference to the accompanying.Fig. 6 shows the simple situation of the cable tv broadcast system that utilizes the present embodiment explanation.That is, in Fig. 6, symbol 11 is center fixtures, has the video signal source 12 that multiple TV signal takes place.

Supply with modulating device 13 from each TV signal of these video signal source 12 outputs, by a plurality of modulation circuits 131 ... 13n carries out modulation treatment respectively, simultaneously, supplies with and encrypts modulating device 14, by a plurality of scrambled devices 141 ..., 14n carries out encryption and modulation treatment respectively.

The output of these modulating devices 13 and the output of encrypting modulating device 14 are exported to network after by superposition device 15 superpositions.As this network, a plurality of (illustrated situation is one) receiving terminal 17 is connected with transmission line 16 at a plurality of points.Television receiver 18 is connected with this receiving terminal 17.And above-mentioned video signal source 12 and encryption modulating device 14 are by 19 controls of the computer installations in the center fixture 11.

In addition, this computer installation 19 generates the control information that is used for to network output, and is defeated by and encrypts modulating device 14.Therefore, for from the TV signal of modulating device 13 output with from the TV signal of the encryption of encrypting modulating device 14 outputs, after the control information of encryption, just can transmit on the superposition to receiving terminal 17.

Here, from the control information of aforementioned calculation machine 19 output shown in the data line Fig. 7 (a) like that, superposition is on the TV signal during the vertical flyback.Shown in Fig. 7 (b), this control information partly is made of data synchronizing signal part, packet kind data division, control data part and checking symbol.And, as the content of control information, shown in Fig. 7 (c), channel number, channel selection frequency and current time etc. are arranged as common information, as individual information indivedual places, channel number and channel selection permissive condition etc. are arranged.

Secondly, Fig. 8 shows the details of above-mentioned receiving terminal 17.That is, in Fig. 8, symbol 20 is input terminals, supplies with the TV signal that sends from center fixture 11.Supply with the TV signal of this input terminal 20 and supply with tuner 21, carry out channel selection according to the indication of station selecting circuit 22 after, supply with sound demodulation circuit 23 and image demodulator circuit 24 respectively.

Wherein, sound demodulation circuit 23 carries out the sound composition in the TV signal of input to be defeated by RF (radio frequency) modulation circuit 25 after the demodulation.In addition, above-mentioned image demodulator circuit 24 with the input TV signal in the iconic element demodulation after be defeated by control information extracting circuit 26 and image decrypt circuit 27 respectively.

At this moment, at first, control information extracting circuit 26 is extracted control information out from the picture signal of input, and is defeated by microprocessor 28.This microprocessor 28 is understood the control information of input, and understands as a result control chart as decrypt circuit 27 according to this.Therefore, image decrypt circuit 27 is decrypted processing according to the indication of microprocessor 28 to the picture signal of importing, and is defeated by RF modulation circuit 25.And this RF modulation circuit 25 will be synthetic with the picture signal of exporting from image demodulator circuit 24 from the voice signal of sound demodulation circuit 23 outputs, and be defeated by above-mentioned television receiver 18 by lead-out terminal 29.

In addition, the operation information of not shown keyboard and straighforward operation portion etc. is by input circuit 30 input microprocessors 28.Therefore, when user's selection operation during desirable channel, this operation information is just analyzed the back by microprocessor 28 and is supplied with station selecting circuits 22.Like this, station selecting circuit 22 is just controlled the channel that tuner 21 makes it to select appointment.In addition, display 31 is connected with microprocessor 28, in order to operate condition of display operation information and receiving terminal 17 etc.

Below, the encryption and the decryption processing of being undertaken by present embodiment are described.That is, in encryption, the corresponding information data that transmits is carried out the 1st and the 2nd tediously long property additional treatments, carries out the cryptographic processing by the 1st time and the 2nd time processed constitutes then.For example, establish information data and be " 83 ",, carry out tediously long property additional treatments, be generated as the 1st tediously long property additional data of " 833 " its additional the 1st tediously long property data (for example " 3 ") that take place by not shown anolog random number generator.

Secondly, and then pass through the 1st tediously long property additional data " 833 " is added the 2nd tediously long property data, generate 4 data.The lowest order that the 2nd tediously long property is data based will comprise the whole addition of itself 4 data the time becomes the condition of " 0 " and selects.That is, at this moment,,, thereby be generated as the 2nd tediously long property additional data of " 8336 " so the 2nd tediously long property data are chosen as " 6 " because the 1st tediously long property additional data is " 833 ".

Then, by everybody of the 2nd tediously long property additional data " 8336 " added 1 respectively, promptly

8+1＝9

3+1＝4

3+1＝4

6+1=7 is generated as the 1st processed of the data of " 9447 ".

And, with the data " 9447 " after the 1st processed as text, as 3 (highest orders)～position 0 (lowest order) of Fig. 9 shown in, be transformed to 2 system numbers with its everybody like that respectively, then with its such as Fig. 9 reading in like that shown in position 3 ' (highest order)～position 0 ' (lowest order), be transformed to 16 system numbers, in the drawings by reading in from bottom to top, be generated as the 2nd processed of the password of " 9178 ", so far, information data " 83 " just encryption be the data of " 9178 ".

In addition, in decryption processing, to the data that receive by respectively according to carrying out the 2nd processed and the 1st processed with above-mentioned opposite order, reproduce the 2nd tediously long property additional data " 8336 ", whether the lowest order according to this whole addition of data of 4 time is " 0 ", judges the correctness of 2 high-order data " 83 ".

Figure 10 is the center fixture 11 of above-mentioned encryption is carried out in expression to control information the flow chart of action.At first, when generating respectively at S1 should be with the common information of TV signal superposition of broadcasting and individual information the time, computer installation 19 just generates control information by they are carried out incorporate transfer management at S2, and is defeated by and encrypts modulating device 14.

So, this encryption modulating device 14 just utilizes anolog random number generator to control information affix the 1st tediously long property data according to the S3 that is controlled at of computer installation 19, generate the 1st tediously long property additional data, in addition, at S4 the 2nd tediously long property data of above-mentioned condition are satisfied in the 1st tediously long property additional data affix, generate the 2nd tediously long property additional data.

Then, encrypt modulating device 14 and the 2nd tediously long property additional data that generates is carried out by the cryptographic processing that the 1st aggregated(particle) structure is handled and the 2nd time processed constitutes, be superimposed at S6 on the TV signal of broadcasting and send (S7) at S5.

Figure 11 is the flow chart of the action of the receiving terminal 17 of expression when receiving the control information carried out this encryption.At first, when when S8 receives control information, microprocessor 28 just carries out above-mentioned decryption processing, the row decoding of going forward side by side to the control information that receives at S9.Then, microprocessor 28 is judged the correctness of the control information of decoding at S10.

And when judgement was correct control information, microprocessor 28 just carried out the processing corresponding with this control information at S11, and transferred to next the processing at S12.In addition, when judging that at S10 when not being correct control information, microprocessor 28 is also transferred to the processing of S12.

Therefore, according to the structure of the foregoing description, owing to be to append to the 1st tediously long property data on the information data by anolog random number generator, even identical information data, the result of encryption is also inequality, so, can make deciphering very difficult.

Figure 12 is the routine flow chart of other actions of the encryption of expression center fixture 11.At first, when generating common information on the TV signal that should be superimposed to broadcasting and individual information respectively at S13, computer installation 19 just generates control information by they are carried out incorporate transfer management at S14, and is defeated by and encrypts modulating device 14.

So, this encryption modulating device 14 just is controlled at the S15 1st tediously long property data corresponding with current time to the control information affix according to computer installation 19, generate the 1st tediously long property additional data, and then, at S16 the 2nd tediously long property data of above-mentioned condition are satisfied in the 1st tediously long property additional data affix, generate the 2nd tediously long property additional data.

Then, encrypt modulating device 14 and the 2nd tediously long property additional data that generates is carried out by the 1st processed and cryptographic processing that the 2nd time processed constitutes, be superimposed at S18 on the TV signal of broadcasting and send (S19) at S17.

Figure 13 is the flow chart of the action of the receiving terminal 17 of expression when receiving the control information carried out this encryption.At first, when when S20 receives control information, microprocessor 28 just carries out the laggard row decoding of above-mentioned decryption processing to the control information that receives at S21.Then, search the 1st tediously long property data in the control information after being included in decoding at S22 microprocessor 28, and judge its correctness.The judgement of the correctness of the 1st tediously long property data be by for example judge the 1st tediously long property data whether with interior corresponding the carrying out of the moment that is contained in the not shown timer in the receiving terminal 17.

And when judgement was the correct the 1st tediously long property data, microprocessor 28 was just judged the correctness of control information at S23, when judgement is correct control information, just carried out the processing corresponding with this control information at S24, and transferred to next the processing at S25.In addition, when judging at S22 when not being the correct the 1st tediously long property data, and judge that at S23 when not being correct control information, microprocessor 28 is also transferred to the processing of S25.

Therefore, according to the structure of above-mentioned the 2nd embodiment, generate the 1st tediously long property data according to current time, even identical information data, the result of encryption is also inequality, so, still can make very difficulty of deciphering.In addition, after the correctness of judgement according to the 1st tediously long property data of current time generation, can judge the correctness of control information.So, can find illegal alter etc. at an easy rate.

Figure 14 is the routine flow chart of other actions of the encryption of expression center fixture 11.At first, when generating common information on the TV signal that should be superimposed to broadcasting and individual information respectively at S26, computer installation 19 just generates control information by they are carried out incorporate transfer management at S27, and is defeated by and encrypts modulating device 14.

So, this encryption modulating device 14 is just issued the 1st corresponding tediously long property data of sequence number according to the S28 that is controlled at of computer installation 19 to control information affix and its transmission, generate the 1st tediously long property additional data, and then, at S29 the 2nd tediously long property data of above-mentioned condition are satisfied in the 1st tediously long property additional data affix, generate the 2nd tediously long property additional data.This transmission distribution sequence number is exactly whenever the sequence number that just increases by 1 when center fixture 11 sends control information.

Then, encrypt modulating device 14 and the 2nd tediously long property additional data that generates is carried out by the 1st processed and cryptographic processing that the 2nd time processed constitutes, and be superimposed at S31 on the TV signal of broadcasting and send (S32) at S30.

Figure 15 is the flow chart of the action of the receiving terminal 17 of expression when receiving the control information carried out this encryption.At first, when when S33 receives control information, microprocessor 28 just carries out above-mentioned decryption processing, the row decoding of going forward side by side to the control information that receives at S34.Then, microprocessor 28 is searched the 1st tediously long property data in the control information after being included in decoding at S35, judges its correctness.The judgement of the correctness of the 1st tediously long property data for example, if inequality with the 1st tediously long property data that are included in the control information that received in the past, just judges it is correct.

And when judgement was the correct the 1st tediously long property data, microprocessor 28 was stored this transmission distribution sequence number at S36 for the correctness of judging the 1st tediously long property data from now on.Then, microprocessor 28 is judged the correctness of control information at S37, when judgement is correct control information, just carries out the processing corresponding with this control information at S38, and transfers to next the processing at S39.In addition, when judging at S35 when not being the correct the 1st tediously long property data, and judge that at S37 when not being correct control information, microprocessor 28 is also transferred to the processing of S39.

Therefore, according to the structure of above-mentioned the 3rd embodiment, be to issue sequence number according to the transmission of control information to generate the 1st tediously long property data, even identical information data, the result of encryption is also inequality, so, still can make very difficulty of deciphering.In addition, after the correctness of judging the 1st tediously long property data that generate according to transmission distribution sequence number, can judge the correctness of control information, so, illegal alter etc. can be found at an easy rate.

According to the various embodiments described above, even identical information data, the result of encryption is also inequality, so, can provide to prevent the illegal very good secrecy broadcasting system of understanding of performance.

Below, describe other embodiment of the present invention in detail with reference to Fig. 6.

In Fig. 6, supply with modulating device 13 from each TV signal of video signal source 12 outputs, by a plurality of modulation circuits 131 ... 13n carries out modulation treatment respectively, simultaneously, supplies with and encrypts modulating device 14, by a plurality of scrambled devices 141 ..., 14n carries out encryption and modulation treatment respectively.

The output of these modulating devices 13 and the output of encrypting modulating device 14 send to network after by superposition device 15 superpositions.As network, a plurality of (illustrated situation is one) receiving terminal 17 is connected with transmission line 16 at a plurality of points.Television receiver 18 is connected with this receiving terminal 17.And above-mentioned video signal source 12 and encryption modulating device 14 are by 19 controls of the computer installations in the center fixture 11.

In addition, this computer installation 19 generates the control information that sends owing to network, and is defeated by and encrypts modulating device 14.Therefore, the control information of encryption just can be superimposed to from the TV signal of modulating device 13 output with on the TV signal of the encryption of encrypting modulating device 14 outputs and send to receiving terminal 17.

Figure 16 shows the details of above-mentioned receiving terminal 17.That is, in Figure 16, symbol 20 is input terminals, supplies with the TV signal of sending from center fixture 11.Supply with the TV signal of this input terminal 20 and supply with tuner 21, carry out channel selection according to the indication of station selecting circuit 22 after, supply with sound demodulation circuit 23 and image demodulator circuit 24 respectively.

Wherein, the sound composition in the TV signal of sound demodulation circuit 23 demodulation input, and be defeated by RF modulation circuit 25.In addition, the iconic element in the TV signal of above-mentioned image demodulator circuit 24 demodulation input is defeated by control information extracting circuit 26 and image decrypt circuit 27 respectively.

At this moment, at first, control information extracting circuit 26 is extracted control information out from the picture signal of input, and is defeated by microprocessor 28.This microprocessor 28 is understood the control information of input, and understands as a result control chart as decrypt circuit 27 according to this.Therefore, image decrypt circuit 27 is decrypted processing according to the indication of microprocessor 28 to the picture signal of importing, and is defeated by RF modulation circuit 25.

This RF modulation circuit 25 will synthesize with the picture signal of exporting from image demodulator circuit 24 from the voice signal of sound demodulation circuit 23 outputs, and is defeated by above-mentioned television receiver 18 by lead-out terminal 29.In addition, this RF modulation circuit 25 also has the function of the composite signal of voice signal and picture signal promptly being exported to television receiver 18 to lead-out terminal 29 according to the indication cut-out of microprocessor 28.

Here, the operation information of not shown keyboard and straighforward operation portion etc. is by input circuit 30 input microprocessors 28.Therefore, when user's selection operation during desirable channel, this operation information is analyzed the back by microprocessor 28 and is supplied with station selecting circuits 22.Therefore, station selecting circuit 22 is just controlled the channel that tuner 21 makes it to select appointment.In addition, display 31 is connected with microprocessor 28, is used for the operate condition of display operation information and receiving terminal 17 etc.

Secondly, in Figure 16, symbol 32 is power supply terminals, supplies with from the outside to exchange commercial power.Supply with the interchange commercial power supply power circuit 33 of this power supply terminal 32, be transformed to the voltage of appointment after, as power supply voltage supplying microprocessor 28.In addition, the voltage from power circuit 33 outputs passes through to control the switch 34 of on/off respectively as internal circuits such as power supply voltage supplying tuner 21, station selecting circuit 22, sound demodulation circuit 23, image demodulator circuit 24, RF modulation circuit 25, control information extracting circuit 26, image decrypt circuit 27, input circuit 30 and displays 31 by microprocessor 28.

For said structure, with reference to its action of flowchart text shown in Figure 17.At first, at S101, when the user turn-offs the not shown mains switch of receiving terminal 17, microprocessor 28 just makes RF modulation circuit 25 become dissengaged positions at S102, the composite signal of sound and image is not supplied with television receiver 18, simultaneously, the demonstration of display 31 is extinguished fully.

Then, microprocessor 28 makes it to select the channel of communicating control information at S103 control station selecting circuit 22, waits for receiving control information at S104, at S105 switch 34 is switched to off-state, stops to above-mentioned internal circuit supply line voltage.And microprocessor 28 judges at S106 whether mains switch is connected, and when judging on, just carries out common reception at S107 and handles.

Therefore, structure according to the foregoing description, when mains switch disconnects, just become the accepting state of the channel of communicating control information, after receiving control information under this state, just stop the internal circuit supply power beyond the microprocessor 28, so, receiving control information, and power consumption reliably is low, thereby can suppress heating.

Secondly, Figure 18 is the routine flow chart of other actions that is used to illustrate Figure 16.At first, at S108, when the user disconnects the not shown mains switch of receiving terminal 17, as previously mentioned, microprocessor 28 just makes RF modulation circuit 25 become dissengaged positions at S109, thereby the composite signal of sound and image is not supplied with television receiver 18, simultaneously, the demonstration of display 31 is all extinguished.

Then, microprocessor 28 makes it to select the channel of communicating control information at S110 control station selecting circuit 22, and the not shown timer of dress carries out timing in S111 sets.And microprocessor 28 judges whether to receive control information at S112, when judging when not receiving, just judges at S113 whether timer has passed through the fixed time and promptly judged whether to overflow.

Here, when judging that timer does not overflow, microprocessor 28 just turns back to the processing of S112.In addition, when judging that timer has overflowed, when the channel that promptly utilizes current selection can not obtain control information at the appointed time, microprocessor 28 was just controlled station selecting circuit 22 at S114, makes it to select other channels, and turns back to the processing of S111.

On the other hand, when when the S112 judgement has received control information, microprocessor 28 switches to off-state at S115 with switch 34, stops to above-mentioned internal circuit supply line voltage.And microprocessor 28 is judged whether on of mains switch at S116, when judging on, just carries out common reception at S117 and handles.

Therefore,, when mains switch disconnects, become the accepting state of the channel of communicating control information, under this state, when not receiving control information more than at the appointed time, just select other channels according to above-mentioned action example.So, receiving control information reliably.

Secondly, Figure 19 is the routine flow chart of other actions that is used to illustrate Figure 16.At first, at S118, when the user disconnected the not shown mains switch of receiving terminal 17, as previously mentioned, microprocessor 28 made RF modulation circuit 25 become dissengaged positions at S119, the composite signal of sound and image was not supplied with television receiver 18.Simultaneously, the demonstration of display 31 is all extinguished.

Then, microprocessor 28 makes it to select the channel of communicating control information at S120 control station selecting circuit 22, and the not shown timer of dress carries out timing in S121 sets.And microprocessor 28 judges whether to receive control information at S122, when judgement does not receive, judges at S123 whether whether timer has passed through the fixed time, promptly overflow.

Here, when judging that timer does not overflow, microprocessor 28 just turns back to the processing of S122.In addition, when judging that timer has overflowed, when the channel that promptly utilizes current selection can not obtain control information at the appointed time, microprocessor 28 was just controlled station selecting circuit 22 at S124, make it according to the next channel of predefined selective sequential, and turn back to the processing of S121.

On the other hand, received control information when judging at S122, microprocessor 28 just switches to off-state with switch 34 at S125, stops to above-mentioned internal circuit supply line voltage.And microprocessor 28 is judged whether on of mains switch at S126, when judging on, just carries out common reception at S127 and handles.

Therefore, according to above-mentioned action example, when mains switch disconnects, just become the accepting state of the channel of communicating control information.Under this state, when not receiving control signal more than at the appointed time, just according to other channels of predefined selective sequential.So, receiving control information reliably still.

Secondly, Figure 20 is the routine flow chart of other actions that is used to illustrate Figure 16.At first, at S128, when the user disconnects the not shown mains switch of receiving terminal 17, as previously mentioned, microprocessor 28 makes RF modulation circuit 25 become dissengaged positions at S129, the composite signal of sound and image is not supplied with television receiver 18, simultaneously, the demonstration of display 31 is all extinguished.

Then, microprocessor 28 makes it to select the channel of communicating control information at S130 control station selecting circuit 22, the 1st not shown timer of dress in S131 sets, carry out timing, then the 2nd not shown timer of dress in S132 sets carries out timing.

And microprocessor 28 judges whether to receive control information at S133, when judgement does not receive, just judges at S134 whether whether the 2nd timer passes through the fixed time, promptly overflow.

Here, when judging that the 2nd timer does not overflow, microprocessor 28 just turns back to the processing of S133.In addition, when judging that the 2nd timer has overflowed, when the channel that promptly utilizes current selection can not obtain control information at the appointed time, microprocessor 28 was just controlled station selecting circuit 22 at S135, makes it to select other channels, and turns back to the processing of S132.

On the other hand, when when the S133 judgement has received control information, microprocessor 28 switches to off-state at S136 with switch 34, stops to above-mentioned internal circuit supply line voltage.And microprocessor 28 judges at S137 whether whether the 1st timer passes through the fixed time, promptly overflow, when judgement has been overflowed, at S138 switch 34 is switched to on-state, beginning turns back to the processing of S130 behind above-mentioned internal circuit supply line voltage.

In addition, when judging that at S137 the 1st timer does not overflow, microprocessor 28 is judged whether on of mains switch at S139, when judging on, just carries out common reception at S140 and handles.

Therefore, according to above-mentioned action example, even after control information is received in the mains switch breaking and connecting, stop under the state of internal circuit supply line voltage, by the 1st timer metering fixed time, after the process fixed time, just can be once more automatically to the internal circuit supply line voltage, thereby become can receiving control information state, so,, also can handle fully even upgrade control information at regular intervals.

Secondly, Figure 21 is the routine flow chart of other actions that is used to illustrate Figure 16.In this action example, in the control information that sends from center fixture 11, be to be object with the data conditions that comprises the control information transmission the plan when control information from now on of expression record send.

At first, at S141, when the user disconnected the not shown mains switch of receiving terminal 17, as previously mentioned, microprocessor 28 made RF modulation circuit 25 become dissengaged positions at S142, the composite signal of sound and image was not supplied with television receiver 18.Simultaneously, the demonstration of display 31 is all extinguished.

Then, microprocessor 28 makes it to select the channel of communicating control information at S143 control station selecting circuit 22, and the not shown timer of dress carries out timing in S144 sets.And microprocessor 28 judges whether to receive control information at S145, when judgement does not receive, just judges at S146 whether whether timer passes through the fixed time, promptly overflow.

Here, when judging that timer does not overflow, microprocessor 28 just turns back to the processing of S145.In addition, when judging that timer has overflowed, when the channel that promptly utilizes current selection can not obtain control information at the appointed time, microprocessor 28 was just controlled station selecting circuit 22 at S147, makes it to select other channels, and turns back to the processing of S144.

On the other hand, when when the S145 judgement has received control information, in the control information transmission plan of microprocessor 28 in S148 just will be included in the control information of this reception stored in the not shown memory of dress, simultaneously, switch 34 is switched to off-state, stop to above-mentioned internal circuit supply line voltage.

Then, microprocessor 28 is judged whether on of mains switch at S149, when judging on, just carries out common reception at S150 and handles.In addition, when judging the mains switch access failure at S149, microprocessor 28 is searched the control information transmission plan of earlier stored in the memory at S151, has judged whether to send the moment of next control information.

And, when judgement is not also arrived the delivery time of next control information, microprocessor 28 just turns back to the processing of S149, when the delivery time of next control information had been arrived in judgement, microprocessor 28 just switched to on-state with switch 34 at S152, and beginning is to above-mentioned internal circuit supply line voltage, simultaneously, control station selecting circuit 22 makes it to select to transmit the channel of next control information, and turns back to the processing of S144.

Here, utilize microprocessor 28 carries out sky system information transmission plan is carried out according to flow chart shown in Figure 22 to the action of memory stores.Promptly, when microprocessor 28 when S153 receives control information, just whether comprised control information transmission plan in the control information of judgement in this reception at S154, when judgement has comprised, after S155 stores into this control information transmission plan in the memory, the action beyond S156 transfers to receiving control information.

Therefore, according to above-mentioned action example, when in control information, comprising expression record and when transmit the data of control information transmission plan of control information from now on, just from the control information that receives, take out control information transmission plan and store in the memory, after, by searching the content of memory, just can be when sending control information automatically to the internal circuit supply line voltage, become can receiving control information state, so, can omit ground receiving control information reliably not.

Secondly, Figure 23 and Figure 24 are the routine flow charts of other actions that is used to illustrate Figure 16.At first, receive at receiving terminal 17 under the state of channel (S157) of appointments, microprocessor 28 judges from the channel that receives whether can obtain control information at S158, when judging can not obtain the time, the timer of dress action in S159 just makes, metering fails to obtain the time of control information.

And microprocessor 28 judges whether not to be not receive for a long time information at S160 according to the time of measuring.When judging is not when not receiving for a long time, S161 just control switch 34 is switched to on-state, beginning is to the internal circuit supply line voltage, simultaneously, control station selecting circuit 22 makes it to select the channel of communicating control information.At this moment, owing to being the channels that receive appointment, so switch 34 was exactly on-state originally at S157 receiving terminal 17.And, switch to the channel of communicating control information forcibly from the channel of initial reception.

Then, microprocessor 28 by the time receiving control information at S163, before switching to the channel of communicating control information, judges whether mains switch is on-state, when judgement is on-state, is just selected the channel of the appointment of original reception at S162 etc. at S164.

And, when judging receiving control information at S158, judge it is when not receiving control information for a long time at S160, when S163 judges that mains switch is not on-state, in addition, after S164, microprocessor 28 just judges whether to have imported by input circuit 30 user's operation information at S165.

Here, when judging when having imported operation information, microprocessor 28 is judged whether on of switch 34 at S166, when judging access failure, carries out and the corresponding processing of importing of operation information at S167, and turns back to the processing of S165.In addition, when judging switch 34 ons at S166, microprocessor 28 is judged whether on of mains switch at S168, when judging on, at S169 switch 34 is set at off-state, and turns back to the processing of S165.

According to above-mentioned action example,, in the time control information can not being obtained for a long time, just select the channel of communicating control information forcibly even receiving terminal 17 receives the state of the channel of appointment.So, can prevent the situation that reception can not obtain control information for a long time.That is, when proceeding to receive when not upgrading control information, misoperation will take place in receiving terminal 17, so, in order to address this problem, in the time can not obtaining control information for a long time, just select the channel of communicating control information forcibly.

Secondly, Figure 25 is the routine flow chart of other actions that is used to illustrate Figure 16.That is, in this action example, the countermeasure when taking place to have a power failure is described.At first, after microprocessor 28 is having a power failure, detect when having recovered energising, just begin to carry out internal initialization and handle (S170), switch 34 is switched to on-state and begin behind the internal circuit supply line voltage initialization process of device, memory and other circuit in carrying out at S171.

Then, microprocessor 28 makes it to select the channel of communicating control information at S172 control station selecting circuit 22, after S173 waits for receiving control information, receives user's operation information at S174.

That is, according to this action example, after having a power failure, be to detect the operation information that receives the user after receiving control information under the state that recovers to switch on, so, for example by upgrading control information, can prevent that just receiving terminal 17 from misoperations taking place.

Secondly, Figure 26 is the routine flow chart of other actions that is used to illustrate Figure 16.That is, in this action example, utilize the current time data that are included in the control information, the situation of receiving terminal 17 being carried out the program timing function is described.

At first, when the user when S175 input requires program timing function operations information to receiving terminal 17, after microprocessor 28 is set processing for the program timing function that realizes requiring to internal circuit at S176, at S177 control station selecting circuit 22, make it to select the channel of communicating control information, judge whether to receive control information at S178.

And when judgement had received control information, microprocessor 28 was extracted the current time data out at S179 from the control information that receives, at S180 executive program timing function.

Therefore, according to this action example, when receiving terminal 17 is required the program timing function, at first, and receiving control information, after the current time data that obtain to be included in wherein, the executive program timing function, so, can realize correct program timing function.

According to the various embodiments described above, thereby can provide not only the very good TV signal receiver of the low performance that can suppress to generate heat of receiving control information but also power consumption reliably.

Below, describe other embodiment of the present invention in detail with reference to Figure 27～Figure 31.

Figure 27 is the structure of the code translator of secrecy broadcasting system of the present invention.In Figure 27, for the part identical, be marked with identical symbol with Fig. 2,, different parts only is described here.

This code translator has example the same earlier with above-mentioned, have the separator 210d that from the subsignal of broadcast singal of encryption, separates voice signal, programme information and individual information, to the encrypted image signal of broadcast singal be decrypted and be transformed to the image decipher 210a of picture signal that can audiovisual, to the encryption voice signal that obtains from subsignal was decrypted and was transformed to the sound decipher 210b of voice signal that can audiovisual and the ID that is used for being included in the ID memory 210j of the ID of individual information and IC-card 220 compares ID comparator 210h.

In addition, this code translator is carrying out also having example the same earlier with above-mentioned aspect the various processing, still, it is characterized in that the processing of a part of microprocessor system is different with the structure of PN generator 310.

PN generator 310 is from carrying out state transition in proper order by the given initial condition of encryption key, is to be used for generating the circuit of PN signal from the state of this migration according to converter logic, still, has the change handling part for the logical circuit that is used to generate this PN signal.This change handling part is characterised in that according to the PNG modification information and changes the logical circuit that is used to generate the PN signal.Figure 28 and Figure 29 are the concrete structure example of this PN generator 310.

Non-linear logical circuit (NF) 312a, 312b, 312c that the PN generator 310 of Figure 28 uses its content to change constitute.When packing commutator pulse into, LFSR211a～211c is taken into 13,11,8 of encryption key Ks respectively, and the state of LFSR211a～211c moves for initial condition regularly according to shift clock from encryption key Ks.

The circuit that NF312a, 312b, 312c use its contents such as EFPROM or RAM to change constitutes, in order to the PNG modification information of the microprocessor system that writes IC-card 220.And, carry out conversion according to the non-linear logic consistent with the PNG information that writes, be used to generate the signal of PN signal by 1 output.

Diverter switch 214 is switched NF312a, 312c according to the switching signal of NF312b, and is defeated by EX-OR213.EX-OR213 is supplied with in the output of 1 register of LFSR211a, and its output EX-OR with NF212a or NF212c is defeated by image decipher 210a and sound decipher 210b as the PN signal.

The state of LFSR211a～211c according to shift clock the initial condition during from given encryption key Ks move, meanwhile, the output of NF312a～312c also changes.Following such state transition to generate aspect at random the PN signal, there is example the same earlier with above-mentioned, still, in PN generator 310 shown in Figure 28, the PN signal of generation is difference with the PNG modification information that writes NF312a～312c.

Like this, the PN generator 310 of Figure 28 just can change the logic that is used to generate the PN signal by changing the converter logic of non-linear logical circuit 312a, 312b, 312c.

The PN generator 310 of Figure 29 just can change converter logic equivalently by changing the state output of LFSR211a～211c.

The PN generator 310 of Figure 29 uses LFSR211a～211c, NF212a～212c, diverter switch 214 and the EX-OR213 the same with example is arranged earlier.And, multiplexer 315a～315c is connected between LFSR211a～211c and the NF212a～212c, constitute register circuit portion with LFSR211a～211c.

Multiplexer 315a, 315b, 315c select 6, select 6, select 6 from the output of the eight bit register of LFSR211c from the output of 11 bit registers of LFSR211b from the output of 13 bit registers of LFSR211a respectively according to the PNG modification information of the microprocessor system of IC-card 220, and supply with NF212a～212c.

NF212a～212c be conversion register circuit portion output, obtain to be used to generate the logical circuit of the signal of PN signal.Like this, the output of the register by switching LFSR211a～211c is also supplied with NF212a～212c, just can change the logic that is used to generate the PN signal.

Control part is that microprocessor system is located on the IC-card 220 of Figure 27, in Figure 27, shows the processing block diagram.In IC-card 220, Kmi is written in the major key memory 210k, and ID is written in the ID memory 210j.

This IC-card 220 has with that example is arranged earlier is the same: use major key Kmi to decipher to handle and the decoder 210f of preservation according to the individual information of separating; Use the job key Kw in the individual information that obtains after the decoding that programme information is carried out decoders for decoding 210e; According to the programme information and the individual information comparison conditions of contract and judge the conditions of contract comparison circuit 210g whether conditions of contract meet; With the switch 210i that the encryption key Ks in the programme information is supplied with PN generator 310.

Like this, example is the same with having earlier, thereby when judging that major key Kmi is consistent with ID and the conditions of contract are consistent and can be decrypted, switch 210i connects, encryption key Ks supply PN generator 210c.

Here, the PNG modification information is supplied with the change handling part of PN generator 310 from the PNG modification information generating unit 210p that generates the PNG modification information.

This PNG modification information generating unit 210p takes out and is included in by programme information after decoder 210e, the 210f decoding or the specific data in the individual information, exports as the PNG modification information.

By above-mentioned processing, when encryption key Ks supplies with PN generator 210c, just according to the converter logic output PN signal that utilizes the PNG modification information to change, supply with image decipher 210a and sound decipher 210b, be decrypted respectively just can obtain after the processing can audiovisual picture signal and voice signal.

The action of the decoder of Fig. 1, except with the relation of PN generator 310 and PNG modification information generating unit 210p, example is identical with having earlier.From subsignal, separate voice signal, programme information and individual information by separator 210d, to be included in ID in the individual information and the ID of IC-card 220 compares by ID comparator 210h, when both were consistent, just the decoder 210f by IC-card 220 used major key Kmi that individual information is deciphered.

In addition, use the job key Kw in the individual information that programme information is deciphered by decoder 210e, when judging that by the conditions of contract comparison circuit 210g conditions of contract meet, the encryption key Ks that is included in the programme information just supplies with PN generator 310.

Here, because PN generator 310 can change the logic that is used to generate this PN signal, so, when input PNG modification information, just carry out state transition from the initial condition order according to this PNG modification information, PN signal that will be corresponding with it is supplied with image decipher 210a and sound decipher 210b, picture signal and voice signal after just can obtaining deciphering.

The PNG modification information is to take out the information that is included in the specific data in programme information or the individual information by PNG modification information generating unit 210p, can be set arbitrarily by TV station.

For example, shown in Fig. 7 (a) like that, programme information in the broadcast singal and individual information superposition are on the data wire during the vertical flyback of picture signal.Shown in Fig. 7 (b), the form of this data wire is made of data synchronizing signal zone, packet kind zone, data area and checking symbol zone.

Control information shown in Fig. 7 (c) is left in the data area.This control information by as the programme information of the common information of each decoder with the different individual information of each decoder is constituted, as common information, the information of channel number and channel selection frequency is arranged usually, in addition, as individual information, the information of indivedual places, channel number and channel selection permissive condition is arranged.Here, the PNG modification information is added in the programme information (common information).The content of this PNG modification information can be changed arbitrarily by TV station.

Like this,, just from programme information, extract out by PNG modification information generating unit 210p in decoder one side at the PNG modification information that TV station inserts, and input PN generator 310.Therefore, the content in that the PNG modification information is only switched in TV station just can change the state transition of the PN generator 310 of each decoder, thereby can generate different PN signals.

Therefore, in the code translator of said structure, can be changed the logic that is used to generate the PN signal of PN generator 310 by TV station arbitrarily, the logic that is used to generate the PN signal is not certain, but variable, so, just be difficult to know its structure.Therefore, its confidentiality can be kept, thereby very high fail safe can be realized.

Particularly, even from the decoder of IC-card to PN generator supply encryption key, the third party also can not know the structure of PN generator according to the relation of encryption key and PN signal, so, fail safe to the confidentiality of system can be provided, thereby can suppress illegal use.

Figure 30 is the structure of other embodiment of code translator of the present invention.In Figure 30, be marked with identical symbol for the part identical, and omit its explanation with Figure 27.

In the present embodiment, it is characterized in that setting area code memory 210q in IC-card 220 will specify the area code of specific region to store in this memory 210q in advance, according to the final designated value of area code decision PNG modification information.

As area code, for example can use TV station's code.According to this structure, even suppose in a certain area (zone) and understood the PN code, can not use this decoder in other areas, the scope that can illegally use is limited in specific area, thereby can suppress the expansion of the illegal scope of application.

In the above-described embodiments, employing be that order sends the structure of PNG modification information one by one basically, still, also can send a plurality of PNG modification informations in advance, select to specify the PNG modification information then.

For example, as shown in Figure 31, as the common information in the control information, PNG modification information specified message is added in channel number and the channel selection frequency, as individual information, the PNG modification information is added in indivedual places, channel number and the channel selection permissive condition.And, from individual information, receive the PNG modification information one by one in decoder one side and do not store, from common information, take out PNG modification information appointed information, and read corresponding PNG modification information.Also can obtain the effect identical by such processing with the embodiment of front.

In addition, in the various embodiments described above, be to use IC-card to change the PN signal formation logic of decoder one side, still, even do not use IC-card, the present invention also can guarantee the enough fail safes to the confidentiality of system.But, ID at this moment is not the ID of IC-card, and for example supposition is by the given ID of decoder itself.In addition, the present invention can also carry out all distortion certainly.

According to the various embodiments described above, thereby can provide simple in structure, can improve the code translator that can suppress the illegal secrecy broadcasting system that uses to the fail safe of the confidentiality of system.

Claims (18)

1. secrecy broadcasting system, it is characterized in that: comprise encryption device and decryption device, thereby this encryption device comprise to information data additional in time process and the 1st tediously long property data that change generate the 1st tediously long property additional data the 1st generating apparatus, additional the 1st tediously long property additional data that is generated by the 1st generating apparatus is carried out the calculation process of appointment and thereby the 2nd tediously long property data that obtain generate the 2nd generating apparatus of the 2nd tediously long property additional data and the 2nd tediously long property additional data that is generated by the 2nd generating apparatus is carried out the encryption apparatus of the cryptographic processing of appointment; Thereby this decryption device comprises deciphering the restoring means that restores the 2nd tediously long property additional data from the code data of encryption apparatus output and judging thereby whether calculation process that the 2nd generating apparatus carries out the 2nd tediously long property additional data that is restored by this restoring means sets up the judgment means of the correctness of the information data that judgement removes the 1st and the 2nd tediously long property data.

2. secrecy broadcasting system according to claim 1 is characterized in that: above-mentioned the 1st generating apparatus obtains to append to the 1st tediously long property data on the above-mentioned information data from anolog random number generator.

3. secrecy broadcasting system according to claim 1 is characterized in that: above-mentioned the 1st generating apparatus is according to generating the 1st tediously long property data that append on the above-mentioned information data constantly.

4. secrecy broadcasting system according to claim 3 is characterized in that: above-mentioned judgment means has by comparing the decision maker of judging the correctness that is included in the 1st tediously long property data in the above-mentioned the 2nd tediously long property additional data that is restored by above-mentioned restoring means with the moment of being measured by above-mentioned decryption device.

5. secrecy broadcasting system according to claim 1 is characterized in that: above-mentioned the 1st generating apparatus generates the 1st tediously long property data that append on the above-mentioned information data according to the distribution sequence number of this information data.

6. secrecy broadcasting system according to claim 5, it is characterized in that: above-mentioned judgment means has storage and is attached to the storage device that is judged to be the above-mentioned distribution sequence number on the correct information data, and has by comparing the decision maker of judging the correctness that is included in the 1st tediously long property data in the above-mentioned the 2nd tediously long property additional data that is restored by above-mentioned restoring means with the distribution sequence number that is stored in the above-mentioned storage device.

7. TV signal receiver, be used to receive superposition the TV signal of the control information that is used to control receiving terminal and, it is characterized in that: had and selecting the control information superposition at the channel selecting device of the channel on the TV signal with under the state that obtains control information from the channel of selecting by this channel selecting device, cut off the control device that the electric power of channel selecting device is supplied with under the state that mains switch disconnects according to the control information control action of superposition on this TV signal.

8. TV signal receiver according to claim 7, it is characterized in that: above-mentioned control device is when the channel selected by above-mentioned channel selecting device can not obtain above-mentioned control information more than at the appointed time, just control above-mentioned channel selecting device, make it to select other channels.

9. TV signal receiver according to claim 7, it is characterized in that: above-mentioned control device is when the channel selected by above-mentioned channel selecting device can not obtain above-mentioned control information more than at the appointed time, just control above-mentioned channel selecting device, make it to select the next channel corresponding with predefined order.

10. TV signal receiver according to claim 7 is characterized in that: above-mentioned control device under the state through the fixed time, begins the channel selection action of this channel selecting device is carried out in above-mentioned channel selecting device power supply after cutting off above-mentioned channel selecting device power supply.

11. TV signal receiver according to claim 7, it is characterized in that: above-mentioned control information comprises the data of the transmission plan of the control information that transmits after the expression, above-mentioned control device is obtaining under the state of above-mentioned control information from the channel of being selected by above-mentioned channel selecting device, storage package is contained in the transmission planning data in this control information, according to power supply and the outage to above-mentioned channel selecting device of the transmission plan control of this storage.

12. TV signal receiver, be used to receive superposition the TV signal of the control information that is used to control receiving terminal and, it is characterized in that: had the channel selecting device of the channel of selecting above-mentioned TV signal and controlling the control device that above-mentioned channel selecting device makes it to select other channels under the at the appointed time above state that can not obtain above-mentioned control information from the channel of selecting by above-mentioned channel selecting device according to the control information control action of superposition on this TV signal.

13. TV signal receiver, be used to receive superposition the TV signal of the control information that is used to control receiving terminal and according to the control information control action of superposition on this TV signal, it is characterized in that: have the channel selecting device that begins under the state of externally fed, to select the channel of above-mentioned control information superposition on TV signal detecting, under the state that obtains above-mentioned control information from the channel of selecting by above-mentioned channel selecting device, receive peripheral operation information.

14. TV signal receiver, be used to receive superposition the TV signal of the control information that is used to control receiving terminal and according to the control information control action of superposition on this TV signal, it is characterized in that: have the channel selecting device of under the state of importing the function operations information that requires utilization to be included in the data in the above-mentioned control information, selecting the channel of above-mentioned control information superposition on TV signal, under the state that obtains above-mentioned control information from the channel of selecting by above-mentioned channel selecting device, carry out above-mentioned functions.

15. the code translator of a secrecy broadcasting system, be used for using the PN signal with image in TV station's one side, voice signal or one of them are encrypted, the use PN signal that the key information that will be used to understand this encryption carries out the secrecy broadcasting system that cryptographic processing and superposition broadcast with above-mentioned coded signal with other sub-information with the encrypted broadcast signals deciphering that receives be transformed to can audiovisual image, voice signal is characterized in that: have the encrypted message that receives at receiving terminal is deciphered the decoder that obtains above-mentioned key information and sub-information, judgement is by the key information judgment means of the true and false of the key information of this decoder acquisition, when being judged to be true key information by this key information judgment means from the sequence of states given by above-mentioned key information carry out state transition and from this transition state generate according to converter logic that thereby above-mentioned PN signal can change the PN signal generation apparatus of above-mentioned PN signal formation logic according to modification information and the sub-information that will obtain by above-mentioned decoder particular data take out and change the PN signal formation logic change device of the formation logic of above-mentioned PN signal generation apparatus according to this modification information as above-mentioned modification information.

16. the code translator of secrecy broadcasting system according to claim 15 is characterized in that: the particular data that is changed arbitrarily by TV station that above-mentioned PN signal formation logic change device will be included in the above-mentioned sub-information takes out as modification information.

17. the code translator of secrecy broadcasting system according to claim 15, it is characterized in that: above-mentioned PN signal formation logic change device keeps being included in a plurality of particular datas in the above-mentioned sub-information, and the particular data that utilization is included in the modification information specific data appointment in the above-mentioned sub-information uses as modification information.

18. the code translator of secrecy broadcasting system according to claim 15 is characterized in that: above-mentioned PN signal formation logic change device is according to the above-mentioned modification information of area information final decision of its broadcast region of expression.

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