`Secb.et et al.
`
`[54] TELEVISION SYSTEM WITH ACCESS
`CONTROL
`
`[75]
`
`Inventors: Claude Sechet, Rennes, France;
`Gerard Babonneau, 14, rue Theodore
`Botrel, 35830 Betton, France; Louis
`C. Guillou, Saint Erblon, France
`[73] Assignees: Etablissement Public de Diffusion
`Dit: Telediffusion de France,
`Montrouge; Gerard Babonneau,
`Betton, both of France
`[21] Appl. No.: 158,499
`Jun. 11, 1980
`[22] Filed:
`[30]
`. Foreign Application Priority Data
`Jun. 15, 1979 [FR]
`France ................................ 79 15400
`Int. Cl.3 ......................... H04N 7/16; H04K 1/04
`[51]
`[52] u.s. Cl. ···································· 358/122; 358/114;
`358/345; 358/347
`[58] Field of Search ................. 358/114, 122, 86, 345,
`358/347
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`3,538,243 11/1970 Shanahan et al .................... 358/124
`3,934,079 1/1976 Barnhart ............................... 358/86
`3,956,615 5/1976 Anderson et al ............... 340/152 R
`
`[11]
`
`[45]
`
`4,354,201
`Oct. 112, 1982
`
`3,997,718 12/1976 Ricketts .................................. 455/2
`4,025,948 5/1977 Loshin ................................. 358/122
`4,045,814 8/1977 Hartung et al ...................... 358/124
`4,081,832 3/1978 Sherman ............................. 358/122
`4,214,230 7/1980 Fak et al ......................... 340/149 A
`
`Primary Examiner-S. C. Buczinski
`
`[57]
`
`ABSTRACf
`A television system with access control comprises a
`transmitter and receivers. The transmitter comprises a
`video signal and sound signal formation circuit, means
`for transmitting these signals and a jamming circuit
`using a service key. Each receiver comprises means for
`receiving the transmitted signals, means for the display
`of the picture and for restoring the sound and an unjam(cid:173)
`ming circuit connected to the reception means and
`working with the service key.
`It also comprises a subscription management center and
`in the transmitter a digital signal generator, a circuit for
`the formation of digital messages and a data broadcast(cid:173)
`ing system and in the receiver a subscription card, an
`extraction circuit for the data, and a circuit for restoring
`the service key. There is also at least one subscription
`card loading station connected to the subscription man(cid:173)
`agement center.
`
`5 Claims, 5 Drawing Figures
`
`42
`LOADING
`STATION
`
`I
`I
`I
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`I
`I
`
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`I
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`-
`L _________ l
`
`APPLE EXHIBIT 1045
`APPLE v. PMC
`IPR2016-00754
`Page 1
`
`
`
`U.S. Patent Oct. 12, 1982
`
`Sheet 1 of 4
`
`4,354,201
`
`SUBSCRIPTION
`MANAGEMENT
`CENTER
`
`10
`
`CL
`
`Cl
`
`/
`
`12
`
`TRANSMITTER L- --.-\--1- ~
`
`20
`I DIGIT~L
`~MESSAGES
`jl FORMAT. ION
`CIRCUIT
`
`2o
`
`-
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`=J"RANSMISSION
`MNS
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`14)
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`I
`I
`I
`I
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`I
`c~LJ~· ~~
`-
`I
`I
`joo
`~ IJ
`I
`L ________ :J
`
`I
`
`LOADING
`STATION
`
`FIG. 1
`
`APPLE EXHIBIT 1045
`APPLE v. PMC
`IPR2016-00754
`Page 2
`
`
`
`~
`V) .
`~ a (1) :s
`0 (') ... -l'l -I,Q
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`"'*
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`53
`
`64
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`67
`
`CIRCUIT
`
`6.9
`COUNTER
`
`PSEUDO-RANDOM
`GENERATOR
`
`FIG. 2
`
`LOADING
`REG.
`
`APPLE EXHIBIT 1045
`APPLE v. PMC
`IPR2016-00754
`Page 3
`
`
`
`U.S. Patent Oct. 12, 1982
`
`Sheet 3 of 4
`
`4,354,201
`
`...J
`~
`0::
`ILl
`1-z
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`·-·-·· ··-· .
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`•
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`1 ~
`j_.
`~'\
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`·-·~- ·-· -~·
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`ca r·-· ·.:n ~'
`'
`(!) ...J
`...J~!
`~~ I
`.
`<:: ~ z I
`I
`~ a:: cJl'
`.
`L
`z ILIL.I
`1-<(
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`•
`m- _.t_ ________ · ·=-~---
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`APPLE EXHIBIT 1045
`APPLE v. PMC
`IPR2016-00754
`Page 4
`
`
`
`0 (')
`l"""
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`-\0
`
`00
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`
`FIG. 4
`
`
`
`
`
` Z86I‘Z1‘moauema"311
`
`SUBSCRIPTION
`CARD
`
`
`
`" '
`
`EXTRACTION i
`*-.314
`7
`I
`T CIUIT j
`
`UNJMMING
`c.Rcun-
`2
`:3...
`
`‘
`
`FIG. 5
`17J017199IlS
`
`EOZWSEW
`
`APPLE EXHIBIT 1045
`APPLE v. PMC
`IPR2016-00754
`Page 5
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`
`
`TELEVISION SYSTEM WITH· ACCESS CONTROL
`
`BACKGROUND OF THE INVENTION
`The present invention relates to a television system
`with access control using a variable electronic key.
`The problem of access control of broadcast informa(cid:173)
`tion mainly consists of the jamming of information on
`transmission by means of an appropriate key, as well as
`unjamming or deciphering on reception by means of an
`identical key, which is only in possession of users who
`have regularly paid a subscription fee.
`Numerous television systems are already known
`which are equipped with jamming means on transmis(cid:173)
`sion and unjamming means on reception. Such systems
`are more particularly described in French Pat. No. 106
`670, German Pat. No. 1 907 580, French Patent Appli(cid:173)
`cation No. 75 34029 filed on Nov. 3, '1975 in the joint
`name of the French State and Telediffusion de France, 20
`French Pat. No. 1 034 776, German Pat. No. 1 254 676
`and U.S. Pat. Nos. 2,510,046, 2,619,530, 2,892,882 and
`2,972,009.
`The jamming processes used in these systems are
`based on the introduction of a displacement of the posi- 25
`tion of the line synchronization pulse on a periodic
`reversal of the complete signal and on the polarity
`change of the video signal or on a combination of these
`operations. In all these processes it is necessary for the
`receivers to receive in some way or the other signals 30
`making it possible to restore the key neceSS¥Y for cov(cid:173)
`ering the clear information.
`The present invention relates to a television system of
`this type, but in which the key which permits unjam(cid:173)
`ming is transmitted to the receivers in an original and 35
`advantageous manner.
`In the prior art systems the transmission of this key
`does not give entire satisfaction because it is not gener(cid:173)
`ally compatible with the recently developed digital
`services and which are being or will be offered to view- 40
`ers. They consist more particularly of three systems: a
`system for digital acquisition and television display of
`pictures organised in writing pages, a system for inter(cid:173)
`active terminal for teletext with call-in by numbering,
`and a system for programmed recording of transmis- 45
`sions on command from the sources.
`The first system consists of a broadcast videotex sys(cid:173)
`tem making it possible to insert alphanumeric informa(cid:173)
`tion organized in pages and in magazines on television
`channels. The second comprises an interactive videotex 50
`system compatible with the first system and giving ac(cid:173)
`cess to data bases (general information, lists, etc.) and to
`interactive services (transactions, messages, instruction)
`by the telephone system. The third system is a pro(cid:173)
`gramme message system consisting of offering by means 55
`of a data broadcasting channel the remote control from
`a transmission source of the recording action by a re(cid:173)
`ceiver (e.g. a magnetoscope) of a preselected television
`programme.
`For broadcasting information these three systems use 60
`means and a process of broadcasting of digital data,
`which is compatible with the broadcasting of the televi(cid:173)
`sion signal.
`
`BRIEF SUMMARY OF THE INVENTION
`The present invention relates to an access control
`means having a complete compatibility with these dif(cid:173)
`ferent systems.
`
`1
`
`4,354,201
`
`2
`To this end the system according to the invention.has
`two essential features:
`(1) In the first place it uses a double key system,
`namely with a service key K making it possible to jam
`information and which changes in a random manner at
`relatively short intervals of approximately a few min(cid:173)
`utes, and a subscription key which can assume several
`values C; depending on the type of subscription, said
`key also changes in a random manner but at longer
`10 intervals of approximately one month. This subscription
`key appears on a subscription card introduced into each
`receiver. The two keys K and C;are combined on trans(cid:173)
`mission for forming messages M;.
`(2) Secondly the messages M; and not the actual ser-
`15 vice key K are transmitted from the transmitter to the
`. receivers. This transmission take.s place in accordance
`with the aforementioned digital data broadcasting pro(cid:173)
`cess, which gives the system compatibility with all digi-
`tal services based on this procedure. On reception the
`messages M; received are combined by the subscription
`key C; supplied by a subscription card, making it possi-
`ble to restore the key K necessary for unjamming the
`signal received.
`More specifically the present invention relates to a
`television system provided with access control means
`and which comprises a transmitter and receivers, trans(cid:173)
`mitter comprising a formation circuit for a videosignal
`organized in lines and in fields and a sound circuit, as
`well as a transmission means for said signals, each re-
`ceiver comprising a reception means for the transmitted
`signals and means for the visual display of the picture
`and the restoration of the sound, wherein it also com(cid:173)
`prises:
`(A) a subscription management centre comprising the
`means for generating a plurality of digital signals consti(cid:173)
`tuting subscription keys C; changing in random manner
`at relatively long intervals of approximately one month;
`(B) a transmitter comprising:
`(a) a digital signal generator constituting a service
`key K, said key changing in randoni manner at rela(cid:173)
`tively short intervals of approximately a few minutes,
`(b) a circuit for the formation of digital messages M;
`obtained from the subscription keys C; and the service
`key K by an algorithm parametered by the subscription
`key, i.e. Mi=Fci (K), said circuit supplying the same
`number of messages as there are subscription keys, said
`messages changing with the service key,
`(c) a system for broadcasting digital data able to insert
`messages Mi in the field blanking intervals of the video
`signal,
`(d) a jamming circuit using the service key K, said
`jamming circuit receiving the video and/or sound sig(cid:173)
`nal and supplying jammed video and/or sound signals
`which are then transmitted to the transmission means,
`said jamming not affecting the messages contained in
`the field blanking intervals;
`(C) in each receiver are provided:
`(a) a subscription card on which is entered a signal
`corresponding to at least one of the subscription keys
`cj,
`(b) a circuit for the extraction of the digital data con(cid:173)
`tained in the signal received, said circuit restoring the
`messages Mi,
`(c) a circuit for restoring the service key receiving on
`65 the one hand messages supplied by the preceding circuit
`and on the other the subscription key Ci supplied by the
`subscription card, said circuit performing an algorithm
`K=Gci (Mi) making it possible to restore the signal
`
`APPLE EXHIBIT 1045
`APPLE v. PMC
`IPR2016-00754
`Page 6
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`
`
`25
`
`3
`corresponding to the service key K used in the transmit(cid:173)
`ter,
`(d) an unjamming circuit connected on the one hand
`to the reception means from where it receives the
`jammed video and optionally sound signals and on the
`other hand to the restoration circuit from where it re(cid:173)
`ceives the service key K, said unjamming circuit sup(cid:173)
`plying unjammed video and optionally sound signals
`which are then transmitted to the means for the display
`of the picture and the restoration of sound;
`(D) at least one subscription card loading station,
`which is connected to the subscription management
`centre from which it receives signals corresponding to
`the different subscription keys C; generated by the said
`centre, each station being able to temporarily receive 15
`subscription cards and write therein one of the subscrip-
`tion keys C;.
`·
`Preferably the jamming circuit comprises a pseudo(cid:173)
`random sequence generator re-initialized at the start of
`each field by the service key K and supplying a digital 20
`jamming signal at the start of each line, and a video and
`optionally sound signal conversion circuit, the conver(cid:173)
`sion being carried out by this circuit being defmed by
`the digital signal supplied by the pseudo-random se-
`quence generator.
`In this case the unjamming circuit comprises a pseu(cid:173)
`do-random sequence generator identical to that of the
`jamming circuit and in the same way re-initialized at the
`start of each field by the service key K and supplying an 30
`unjamming digital signal at the start of each line and a
`circuit able to carry out the reverse conversion to that
`of the jamming circuit on the video and optionally
`sound signal, said conversion being determined by the
`digital unjamming signal supplied .by the pseudo-ran- 35
`dom sequence generator.
`The jamming operation on transmission can be of any
`known type and particularly in accordance with the
`processes described in the documents referred to here(cid:173)
`inbefore. However, according to an advantageous vari- 40
`ant a means based on a circular permutation of the sam(cid:173)
`ples to be jammed is used.
`Naturally the jamming operation can affect both the
`picture and the sound. With regard to the transmission
`of sound it can be carried out either by an ordinary 45
`sound channel, or a digital channel using the field blank(cid:173)
`ing intervals and operating in accordance with the digi-
`tal data broadcasting procedure, or a digital channel
`using the line blanking intervals, or a digital channel
`using supplementary signals inserted in the chromi- 50
`nance colour bursts.
`The means used for the transmission of sound can be
`marked by means of bits forming part of the service key
`K.
`BRIEF DESCRIPTION OF THE DRAWINGS
`The invention is described in greater detail hereinaf(cid:173)
`ter relative to non-limitative embodiments and the at(cid:173)
`tached drawings, wherein show:
`FIG. 1-a block diagram of a television system with 60
`access control according to the invention.
`FIG. 2-diagrammatically jamming means using a
`circular permutation of samples.
`FIG. 3-the standard preferably adopted for the
`videosignal.
`FIG. 4--diagrammatically the locations in the field
`synchronization signal of the signals indicating a change
`of key.
`·
`
`65
`
`4,354,201
`
`4
`FIG. 5-the organization of the key change detection
`means.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENTS
`The system shown in FIG. 1 frrstly comprises a sub(cid:173)
`scription management centre 10 which generates a plu(cid:173)
`rality of signals constituting subscription keys C;, which
`change in a random manner at relatively long intervals
`10 of approximately one month.
`The actual television system is organized around the
`transmitter 12 and has a plurality of receivers 14.
`Transmitter 12 comprises: ·
`(a) a circuit 16 for the formation of television signals
`incorporating a part relative to a videosignal carried by
`a connection 17 and a part relative to the sound carried
`by a connection 19;
`(b) a generator 18 of a signal constituting a service
`key K, said key changing in a random manner at rela(cid:173)
`tively short intervals of approximately a few minutes;
`(c) a circuit 20 for the formation of digital messages
`M; from subscription key C; generated by centre 10 and
`the service key K generated by generator 18, for which
`purpose the circuit 20 performs an algorithm parame(cid:173)
`tered by the subscription keys, i.e. M;=Fc; (K), and
`supplies the same number of messages M; as there are
`subscription keys, said messages changing with the
`service key K;
`(d) a digital data broadcasting system 22 able to insert
`messages M; into the field blanking intervals of the vid(cid:173)
`eosignal coming from circuit 16 by means of connection
`17;
`(e) a jamming circuit 24 using the service key K for
`jamming the video and/or sound signal, said jamming
`not affecting the messages M; contained in the field
`blanking intervals, the jammed signal supplied by this
`circuit are then transmitted to the transmission means
`26.
`Each receiver 14 of the present system contains:
`(a) a broadcast signal reception means 30;
`(b) an unjamming circuit 32 connected to the recep-
`tion means 30 from which it receives the jammed video
`and optionally sound signals and which operates by
`means of the service key K, supplying the unjammed
`video and sound signals respectively carried by connec-
`tions 31 and 33;
`(c) a circuit 34 for the extraction of digital data con(cid:173)
`tained in the video signal received, said circuit restoring
`messages M; by a connection 35;
`·
`(d) a subscription card 36 on which is entered a signal
`corresponding to at least one of the subscription keys
`C,;
`(e) a circuit 38 for restoring the service key K from
`55 messages M;supplied by the circuit34 and the subscrip(cid:173)
`tion key C; supplied by the subscription card 36, said
`circuit 38 performing an algorithm K = Gc; (M;) making
`it possible to restore the ·signal corresponding to the
`service key K used in the transmitter, said key then
`being addressed to the unjamming circuit 32;
`(f) means 40 for the display of the pictures and the
`restoration of sound.
`The system shown also has at least one loading sta(cid:173)
`tion 42 suitable for the subscription card 36. This station
`is connected to the subscription management centre 10
`from which it receives signals corresponding to the
`different subscription keys C; generated by the centre.
`Each station 42 is temporarily able to receive the sub-
`
`APPLE EXHIBIT 1045
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`Page 7
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`4,354,201
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`10
`
`20
`
`(2) 1r -1 is calculated being the opposite to the modulo
`261_1 by an arithmetic programme using a variant of
`the Euclidian algorithms;
`(3) a first multiplication is performed by another
`arithmetic programme v=KTr-1 modulo (261_1);
`(4) 'Y is calculated, being the opposite of C modulo
`2127-1, by a programme similar to that of (2);
`(5) finally the message is calculated by a programme
`similar to (3): M=y·(v+264·7r) modulo (2127 -1).
`The programmes necessary for these calculations can
`be developed by a type 8080 microprocessor of the
`INTEL Company.
`All the messages Mi in force constitute. the access
`control information associated with the broadcast ser(cid:173)
`vice. According to the essential feature of the invention
`this information is broadcast by the digital data broad-
`casting process at circuit 22 and is restored on reception
`at circuit 34.
`This digital data broadcasting process is known per
`se.
`Broadcasting is performed by bringing the data into
`packets. Each packet occupies the active part of the
`television line making it possible to ensure a good com(cid:173)
`patibility with the conventional modes of use of the
`channel.
`As in the present invention the radio channel is allo(cid:173)
`cated to a television programme, only the marginal
`resource COQStituted by the field blanking interval can
`be used for the transmission of messages M.
`In the digital broadcasting process each packet has
`two parts, one called the prefix and the other called the
`data block. The prefix is used for the management of the
`packet and has eight octets, two for the synchronization
`of the bits, one for. the octet synchronization, three
`carry the channel code, including its protection, one
`carries the continuity symbol and the final octet de(cid:173)
`scribes the format (or length) of the data block.
`The data block follows the prefix. Its maximum
`length is dependent upon the timing-pulse rate and the
`active duration of the line. The timing-pulse rate is
`adapted to the channel band width. The modulation
`used is the "non-return to zero" (NRZ) brought into a
`· form for adapting the spectral energy distribution to the
`transmission channel.
`When the messages Mi have been transmitted and
`received by the digital broadcasting process it is neces(cid:173)
`sary to reconstitute the service key K. This is the func-
`tion of circuit 38. This circuit is programmed to develop
`an algorithm K = Gci (Mi) field algorithm. The opera(cid:173)
`tions are as follows:
`1. The message Mi (127 useful bits) is acquired octet
`by octet and a multiplication by Ci is carried out on the
`first field CG (2127 -I). Thus a word J.t is formed.
`
`scription cards and to write therein in a lasting manner
`(e.g. in a memory) one of the subscription keys Ci.
`For the purpose of illustrating the operation of this
`double key system it is possible to take the example of a
`subscription scheme using four types of subscriptions,
`i.e. one month, three months, six months and one year.
`In addition to its duration a subscription is characterized
`by the starting month. In the case of such a scheme for
`a given month and for a given service there are conse(cid:173)
`quently 22 subscription keys which are likely to be used
`by users, namely one monthly key, three quarter-yearly
`keys, six half-yearly keys and twelve yearly keys.
`Every month the subscription management centre 10
`supplies transmitter 12 with a list of 22 subscription keys
`Ci for each service broadcast by this transmitter. In 15
`addition, it supplies loading stations 42 with another list
`of four keys for starting the following month (one
`month, three months, six months and one year), for each
`service with the subscription rates.
`A suitable machine installed at each point of sale
`enters certain of these keys in the form of subscription
`blocks on the cards 36. A subscription block can for
`.
`example consist of four fields:
`(1) a service code having 16 bits designating the ser- 25
`vice in question;
`(2) a subscription symbol of 8 bits having which char(cid:173)
`acterizes the subscription for a service in question,
`whereby 2 of said bits indicate the subscription type (1,
`3, 6 or 12 months) and the 6 others indicate the subscrip- 30
`tion starting month (1 to 60 modulo 5 years);
`(3) a subscription key of 128 .bits which is the funda(cid:173)
`mental information of the block;
`(4) a cyclic redundancy code of 16 bits and relates to
`the preceding 152 bits and makes it possible to check the 35
`subscription block before using the same.
`Thus, a subscription block. is formed by 168 bits, i.e.
`21 octets. Such a block can easily be entered in a credit
`card-type support provided with a PROM memory
`(Programmable Read-Only Memory) with a capacity of 4D
`4096 bits usable for this purpose. Such a card can re(cid:173)
`ceive up to 24 subscription blocks having the indicated
`characteristics.
`For each paying service, approximately every five
`minutes, a new service key K is generated in a random 45
`manner in the transmitter. Thus, during a session of a
`service (one or several hours) a few dozen service keys
`can follow one another. As soon as a transmitter gener(cid:173)
`ates a new service key K it calculates for each subscrip(cid:173)
`tion key Ci in operation for said service a message Mi by 50
`an algorithm in which the keys Ci act as parameters.
`Thus, for a sevice with the subscription scheme re(cid:173)
`ferred to hereinbefore 22 different messages are in force
`at all times. The life of a message is equal to that of the 55
`service key K and for a given service there is the same
`number of messages as there are subscription keys being
`used at all times.
`The calculation of the messages Mifrom the subscrip(cid:173)
`tion keys Ci and key K takes place in the transmission 60
`centre by means of circuit 20, organized around a mi(cid:173)
`cro-processor.
`Such a circuit is programmed so as to realize an algo(cid:173)
`rithm using the subscription keys Ci (127 bits) and the
`service key K (56 bits) in the following way:
`(1) a confusion redundancy word 1r is formed which
`consists of 61 bits generated at random on each perfor(cid:173)
`mance of the algorithm;
`
`p.=M·C modulo (2127 -I).
`
`On the basis of the construction of M on transmission
`bits 1 to 61 of J.t represent the word v, while bits 65 to
`125 represent the word Tr. Obviously bits 62, 63, 64, 126
`and 127 must be zero. If they are not zero the word vis
`brought to zero before continuing the calculation.
`1r and v are multiplied on
`the second field
`CG(261-1), which brings about the disappearance of
`the confusion redundancy and one obtains K = v·Tr mod(cid:173)
`ulo (26L 1).
`A further probability test now takes place, because as
`K has 56 useful bits, bits 57, 58, 59, 60 and 61 must be
`
`65
`
`IUOiiiiliMIIW
`
`!iiiiiiiiUi
`
`APPLE EXHIBIT 1045
`APPLE v. PMC
`IPR2016-00754
`Page 8
`
`
`
`7
`zero. If this is not the case K is brought to zero before
`continuing the operation.
`The 56 useful bits of K are then available in the form
`of 8 uneven octets.
`The jamming and unjamming of the video signal
`taking place respectively in circuits 22 and 52 can ad(cid:173)
`vantageously be obtained by a process wherein the
`following operations are performed. The signal to be
`jammed is firstly sampled and then the samples are
`inserted in a video signal line. The n samples V o to V n 10
`constituting are permutated in circular manner by
`(p+ 1) positions, so that the samples V(p+ 1) to Vn are
`placed before samples V 0 to Vp, the samples are then
`transmitted in this permutated order. On reception the
`samples of the jammed signal are again circularly per- 15
`mutated by (n-p) positions to restore the initial se(cid:173)
`quence. The number n is determined line by line, ac(cid:173)
`cording to a law which is fixed by the transmitter and is
`transmitted to the receivers.
`FIG. 2 shows the block diagram of a jamming circuit 20
`which can be used in the invention. The video signal to
`be jammed is introduced by connection 50 into a sepa(cid:173)
`rating circuit 51 which supplies a line synchronization
`pulse to a time base circuit 52 and the luminance and
`chrominance signals to a sampling circuit 53. In the time 25
`base circuit 52 the line synchronization pulses are used
`in conventional manner for generating timing signals H
`at the sampling frequency and line parity and imparity
`signals 2p and 2j respectively. The output of the sam(cid:173)
`pling circuit 53 is connected in parallel to the signal 30
`inputs of two AND gates 54 and 55, whose outputs are
`respectively connected to two input circuits 56 and 57.
`The outputs of these circuits are respectively connected
`to the inputs of two delay circuits 58 and 59, respec(cid:173)
`tively connected to the output circuits 60 and 61. The 35
`outputs of circuits 60 and 61 are connected to the inputs
`of an OR gate 62, whose output is connected to the
`input of a smoothing circuit 63 joined to a circuit 64 in
`which a line synchronization pulse is inserted into the
`signal leaving 63.
`The coder of FIG. 2 also comprises a pseudo-random
`digital sequence generator 65 which can be a ten-stage
`shift register provided with nine re-Iooping points,
`whereby there is direct re-Iooping between last and first
`stage. The-eight intermediate loops are put into effec- 45
`tive operation when a level 1 is applied to the control
`input of the corresponding stage. These re-looping con(cid:173)
`trollevels are applied from a loading register 66, which
`permanently contains an eight bit word. This word
`defines the configuration of the generator. For each 50
`field synchronization signal transmitted by the separat(cid:173)
`ing circuit 51 and carried by a connection 67 to a regis-
`ter 68 which carries a ten bit word generator 65 is ini(cid:173)
`tialized in accordance with this word, each stage assum(cid:173)
`ing the state defined by the corresponding bit. For each 55
`field the same digital sequence of ten bits is generated
`with the timing of the line synchronization pulses sup(cid:173)
`plied by circuit 51 to generator 65. The eight bit word
`contained in register 66 and the ten bit word contained
`in register 68 together form the axis key to the jammed 60
`transmission.
`The output of generator 65 supplies a ten bit word to
`the initialization input of a counter 69, whose counting
`input receives the timing pulses H from the time base
`circuit 52. Counter 69 counts backwards on transmis- 65
`sion. When counter 69 is not at zero its signal output is
`at level 1, but as soon as it is at zero this output passes
`to 0.
`
`40
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`4,354,201
`
`~
`The second input of gate 54 is connected to an output
`2p of 52 in such a way that the uneven line signals trans(cid:173)
`mitted by circuit 53 are transmitted to circuit 54. The
`second input of gate 55 is connected to the output 2p in
`such a way that the even line signals are transmitted to
`circuit 57.
`One control input of circuit 56 is connected to the
`output of an AND gate 70, whose first input is con(cid:173)
`nected to the output 2p of 53 and whose second input is
`connected to the output of counter 69. The control
`input of circuit 57 is connected to the output of an AND
`gate 61, whose first input is connected to output 2jj of 52
`and whose input is connected to the output of counter
`69.
`The control input of circuit 60 is connected to the
`output 29 of 52, whilst the control input of circuit 61 is
`connected to output 2p of 52.
`Finally an input of circuit 64 is connected to an out(cid:173)
`put of circuit 52 which supplies a synchronization signal
`S', deduced from the incoming synchronization signal.
`The circuit of FIG. 2 functions as follows. During an
`uneven line signal 2p is at the high level, gate 54 is open,
`circuit 60 is open towards gate 62, circuit 61 is closed
`and gate 55 is closed. In addition, gate 70 is closed,
`whilst gate 71 is open and the output of counter 69 is at
`high level. Thus, samples from an uneven line enter
`circuit 58 and jammed samples from the uneven line
`leave it.
`During the following even line signal 2p is at high
`level, gate 51 is closed, circuit 60 is closed, circuit 61 is
`open and gate 55 is open. Moreover, gate 61 is closed
`whilst gate 60 is open and output of 69 is at high level.
`The first samples are transmitted to the input of 58,
`whilst the last are moved towards the output of 58, the
`content of 58 remaining unchanged until the end of the
`even line. Finally there is an uneven line and the opera(cid:173)
`tion described hereinbefore is repeated. Jamming of the
`even lines takes place in the same way with respect to
`circuit 59.
`It is clear that the circuit of FIG. 2 can be used on
`reception for restoring the initial forms of lines by using
`the same circuits 66 and 68, by connecting counter 60 in
`such a way that after its initialization at each line by 60
`it counts towards its maximum content instead of count(cid:173)
`ing towards zero as was the case for the coder on trans(cid:173)
`mission.
`When the treated samples are in analog form, the
`delay circuits 58 and 59 are advantageously load trans(cid:173)
`fer circuits. When the processed samples are in the
`coded digital form these delay circuits are shift regis(cid:173)
`ters.
`In the described embodiment the digital signal used
`by the pseudo-random sequence generator contains
`10+8= 18 bits, but the key can be constituted by a word
`having more than 18 bits, e.g. 32 bits. The 14 other bits
`of the key make it possible to determine which conver(cid:173)
`sion functions are active and which are not (2bits), what
`division of the resource is chosen, what relationship
`exists between the 10 bits of the shift register and certain
`parameters of the conversions of pure delays or circular
`displacement. In general terms the key can carry com(cid:173)
`plementary information relating to the possible configu(cid:173)
`rations of the signal. This is utilised for providing the
`possibility of repiacing a single full definition sound and
`video programme by four independent low definition
`programmes, this result being obtained by dividing up
`the screen space into four quadrants receiving four
`independent pictures obtained by reduction by digital
`
`APPLE EXHIBIT 1045
`APPLE v. PMC
`IPR2016-00754
`Page 9
`
`
`
`4,354,201
`
`30
`
`35
`
`9
`means in the case of the video and the sound channel
`into four narrow band sound channels. This possibility
`can be provided in the definition of the jamming system.
`The general public receivers are not necessarily pro(cid:173)
`vided with these means which can be reserved for spe(cid:173)
`cial users.
`The jamming of the picture sensitizes the latter to
`transmission faults and makes it necessary to provide
`redundancies. In the video standard adopted a time
`interval of 2.6 ,_.,s is. provided for this purpose. This 10
`interval remains free of any signal before jamming. This
`standard is shown in FIG. 3. Each video signal line has:
`a blanking interval Is which is riot affected by the
`pseudo-random transformations or conversions, except
`with regard to the content of any digital signal which 15
`may be present, said interval containing the line syn(cid:173)
`chronization and optionally a digital channel N for
`carrying sound.
`an interval Ircontaining the picture which is affected
`by the pseudo-random transform