115)
`United States Patent
`4,337,483
`[11]
`Guillow
`
` [45] Jun, 29, 1982
`
`3/1978 Sherman...........
`4,081,132
`aaa 358/122
`
`neni 340/149 A
`4,214,230 7/1980 Fak etal. ......
`
`Primary Examiner—Howard A. Birmiel
`(57]
`ABSTRACT
`A text video-transmission system comprising an infor-
`mation emitting center and receiving stations, the emit-
`ting center comprising encryption meansusing an oper-
`ating key, each receiving station comprising decryption
`means using the operating key, wherein in this system,
`the encryption meansofthe emitting center comprise: a
`generatordelivering a numericalsignal representing an
`operating key K,this key changing randomly at prede-
`termined intervals; an automatic encryption means
`comprising: a discriminator with an input connected to
`a magazine memorizing circuit from which it receives
`clear octets, this discriminator being capable ofdistin-
`guishing, among these clear octets, those wherein the
`7th and 6th binary elements are zero, an OR-exclusive
`logic circuit connected to the discriminator from which
`it receives octets wherein the 6th and/or 7th binary
`elementsare notzero,this logic circuit having an output
`whichcarries encrypted octets; a generator of encoding
`octets, the decoding means of each receiving station
`comprising: a generatorof a numerical signal represent-
`ing the operating key K in use in the emitting center,
`automatic decryption means comprising: a discrimina-
`tor adaptedto distinguish, among the encrypted octets,
`those wherein the 7th and 6th binary elements are zero,
`an OR-exclusive logic circuit connected to the discrimi-
`nator; and a generator for decoding octets.
`
`11 Claims, 10 Drawing Figures
`
`(54] TEXT VIDEO-TRANSMISSION SYSTEM
`PROVIDED WITH MEANS FOR
`CONTROLLING ACCESS TO THE
`INFORMATION
`Inventor:
`Louis C. Guillou, Bourgbarre-Saint
`Erblon, France
`
`[75]
`
`[73] Assignees: Etablissement Public de Diffusion dit
`“Telediffusion de France”,
`Montrouge; L’Etat Francais,
`represente par le Secretaire d'Etat
`aux Poste et Telecommunications
`(Centre National d’Etudes des
`Telecommunications), Issy les
`Moulineaux, both of France
`
`[21] Appl. No.: 117,234
`[22] Filed:
`Jan, 31, 1980
`[30]
`Foreign Application Priority Data.
`Feb. 6, 1979 [FR]
`France wsseesceceeesssstseesessnensee 79 02994
`[Si]
`Tint, C03 oovecescccsessssassens HO4N 7/16; HO4K 1/00
`[52] BSH cachaneneniieuacinas 358/114; 340/706;
`358/147; 340/825.54; 340/825.5
`[58] Field of Search .........0...::00 455/2; 358/86, 114;
`340/147 LP, 149 A, 149 R, 152 R, 152 T, 706;
`178/22.08
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`1/1976 Barnhart ........c.ccccscereeseeesees » 358/86
`3,934,079)
`
`5/1976 Andersonetal. ...
`+. 340/152 R
`3,956,615
`3,997,718 12/1976 Ricketts ..........-si vadiaadedudvuiceaseuns 455/2
`
`
`
`
`PMC Exhibit 2091
`Apple v. PMC
`IPR2016-00753
`Page 1
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`PMC Exhibit 2091
`Apple v. PMC
`IPR2016-00753
`Page 1
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`

`

`
`U.S. Patent—sun. 29, 1982 Sheet 1 of 9 4,337,483
`
`INFORMATION cr7
`| EMITTING
`
`
`6
`
`CENTER.
`
`RECEIVING
`STATIONS
`
`,
`
`|
`beeee
`
`
`
`PMC Exhibit 2091
`Apple v. PMC
`IPR2016-00753
`Page 2
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`Y\
`
`
`
`RECEIVING
`cc
`
`DIGITAL
`LINE
`
` T
`
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`IPR2016-00753
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`

`

`U.S. Patent
`
`sun. 29, 1982
`
`Sheet 2 of 9
`
`4,337,483
`
`INFORMATION
`SOURCE
`
`GENERATOR
`
`
`EMITTING
`CENTER ~~
`
`2
`
`
`
`
`
`
`
`MEANS
`
`i
`
`GATE
`
`Le _|
`
`FIG 20 oes
`
`—_— Oo Cr erierrwmWDlOOonOmercrrr |
`RECEIVING
`|
`RECEIVING
`|
`STATION
`CCT
`“4 |
`36 OPERATING
`|
`U
`A |
`|
`VIDEO
`|
`LINE
`|
`|
`|
`|
`6
`|
`|
`DISCRIMINATOR
`JSS eS" —|
`8
`|
`|
`|
`
`DIGITAL
`LINE
`
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`Apple v. PMC
`IPR2016-00753
`Page 3
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`Apple v. PMC
`IPR2016-00753
`Page 3
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`

`

`U.S. Patent
`
`Jun. 29, 1982
`
`Sheet 3 of 9
`
`4,337,483
`
`¢OldA
`a@Lo.
`[Seso©SALV9
`
`BAISNTOX3-4O~Ve
`
`do14-di4
`
`os
`
`VS
`
`9S
`
`8S
`
`O02
`
`H
`
`90719
`
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`Apple v. PMC
`IPR2016-00753
`Page 4
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`Apple v. PMC
`IPR2016-00753
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`

`
`
`U.S. Patent—sun.29, 1982 Sheet 4 of 9 4,337,483
`
`
`
`
`
`
`
`GENERATOR |
`
`GENERATOR
`
`Pg By Be By By Bz Be
`
`By
`
`SEQUENCER
`
`
`be eeee
`
`FIG. 5 GENERATOR>-26 ( 26”)
`
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`Apple v. PMC
`IPR2016-00753
`Page 5
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`IPR2016-00753
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`

`
`
`U.S. Patent—sun. 29, 1982 Sheet 5 of 9 4,337,483
`
`
`
`
`
`FIG. 6
`
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`Apple v. PMC
`IPR2016-00753
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`Apple v. PMC
`IPR2016-00753
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`

`

`U.S. Patent
`
`Jun. 29, 1982
`
`Sheet 6 of 9
`
`4,337,483
`
`CENTER
`
`SUBSCRIPTION
`HOLDER
`|106~
`108
`
`DISCRIMINATOR
`
`RECEIVING|
`|
`!
`__|
`{|
`
`
` EMITTING
`
`
`| |||
`
`CHARGING
`|
`K RESTORING
`
`STATION
`-—{
`CIRCUIT
`4 |
`nos ay
`FIG. 7
`*
`
`1
`_
`|
`|
`|
`\ i ——_—
`
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`IPR2016-00753
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`IPR2016-00753
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`

`U.S. Patent
`
`Jun. 29, 1982
`
`Sheet 7 of 9
`
`4,337,483
`
`TOYLNOD :AYOWSNOL
`
`LINDYID
`
`oe)
`
`SS9VSS3N|royiNODSSa900SHL
`
`choz
`
`8oda
`
`40NOILISOdWOD
`
`39vd
`
`AIBWASSV
`
`MO71S
`
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`Apple v. PMC
`IPR2016-00753
`Page 8
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`Apple v. PMC
`IPR2016-00753
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`

`U.S. Patent
`
`Jun. 29, 1982
`
`Sheet 8 of 9
`
`4,337,483
`
`
`
`AYOWSINLINDYID
`
`
`
`39vd9NIGOI30
`
`
`
`ONINNYOSoe=LI____G@Nvuzqoo3G4oN0DCY
`
`oNISS350Ud0880|TWLIOIG|GUVOBASID|aPo7Ng_
`
`aAvldsiqYOLWU3N39
`
`SNW3W&Fl
`,||||Ta)SrlrrErL|LinoUl!NOLLONNP
`Nol1313S!-|__
`eatenae4:|seesl6Ol
`[Aearennai
`
`YaNVadSGno7
`
`ONIAIZOSY
`
`LINDYID
`
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`IPR2016-00753
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`

`U.S. Patent
`
`Jun. 29, 1982
`
`Sheet 9 of 9
`
`4,337,483
`
`DECODING
`CIRCUIT
`
`DISCRIMINATOR
`
`JUNCTION
`
`42
`
`
`Cone
`
`MEMORY
`
`K RESTORING
`CIRCUIT
`
`SUBSCRIPTION
`HOLDER
`
`|
`
`be
`
`|
`
`OPERATING
`K SUPPLY
`
`36
`
`FIG. 10
`
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`IPR2016-00753
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`

`1
`
`4,337,483
`
`TEXT VIDEO-TRANSMISSION SYSTEM
`PROVIDED WITH MEANS FOR CONTROLLING
`ACCESS TO THE INFORMATION
`
`BACKGROUND OF THE INVENTION
`
`2
`means 6 for composing a magazine consisting of
`pages organised into lines of characters, if the supplier
`of the information has not already composedit in this
`way;
`a magazine memorising circuit 10 in the form of nu-
`merical signals grouped into octets (8 binary elements);
`a junction 11 connected to the circuit 10,
`a distribution multiplexer 12 serving to form bundles
`of octets and insert information in thelines ofa televi-
`sion signal, this device using the procedure mentioned
`above,
`L.
`Eachreceiving station comprises:
`a circuit 14 for receiving and demodulating saidtele-
`vision signal;
`a line 16 for processing the videopicture signals;
`a line 18 for processing numerical signals, this line
`comprising notably a numerical data decoder, and fi-
`nally
`display means 20.
`In a system ofthis kind, the flux of information from
`the suppliers of information to the distribution, centres
`has the following general characteristics.
`The source 5, whichis an information-“supplying data
`bank,
`is,
`for example, a meteorological service, the
`Stock Exchange, an information agency, etc. This bank
`supplies the composing means 6 which puts the infor-
`mation into pages of the suitable format.
`To indicate the size scales involved,it can be stated
`that, in the case of an experimental magazine produced
`for share values, there may be about 80 pages containing
`on average 800 octets, i.e. a total of 64000 octets. A
`shares magazine of this kind uses a resource of 10 lines
`per frame. A television line lasts 64 zs and can carry 32
`useful octets, and there are 50 frames per second.. Thus,
`the resource of a line/frame makesit possible to trans-
`mit 50X32 8=12800 b/s (binary elements per sec-
`ond). The entire magazine is thus transmitted in
`
`The present inventionrelates to a text video-transmis-
`sion system provided with meansfor controlling access
`to the information.
`It can be usedin the transmission and display of infor-
`mation on television receivers for purposes of entertain-
`ment, information or education. The invention applies
`essentially to a broadcase system (i.e. unidirectional) by
`means of which alphanumerical information organised
`into pages and magazines can beputintotelevisionlines
`and to interactive system (i.e. two-directional) affording
`access to data bases (general information, directories,
`etc.) and to interactive services (transactions, messages,
`education) through the telephone system.
`In the first system, the distribution of informationis
`effected by a method ofdistribution in bundles, compat-
`ible with the distribution of the television signal.
`These systems have already been described in numer-
`ous articles or patent applications. Reference is made
`hereinafter essentially to the so-called ANTIOPEsys-
`tem, a detailed description of which can be found par-
`ticularly in the following documents:
`the article by Y. GUINETentitled: “Etude compara-
`tive des
`systémes de
`télétexte en radiodiffusion.
`Quelques avantages de la diffusion des donnees par
`paquets appliquee au teletexte” which appeared in the
`U.E.R. Cahier Technique, no. 165, October 1977, pages
`242 to 253;
`the article by B. MARTI and M. MAUDUITentitled
`“ANTIOPE,service de télétexte”, which appeared in
`the journal “Radiodiffusion Télévision”, 9th year, no.
`40. November-December 1975, 5/5, pages 18 to 23;
`the “Spécification du Syst®me de télétexte ANTI-
`64x8
`OPE”, edited by the Centre Commun d’Etudes de Télé-
`12.8 x 10 = 4 seconds,
`vision et Télécommunications (CCETT);
`French patent application no. 75 18319, filed on June
`6th 1975 and entitled “Data distribution system”;
`French patent application Peg. no. 76 27212, filed on
`Sept. 6th 1976 and entitled “System for the numerical
`transmission and displaying of text on a television
`screen”;
`French patentapplication no. 76 29034, filed on Sept.
`22nd 1976 and entitled “Improvements to systems for
`the numerical transmission and displaying of texts on a
`television screen”;
`the French application fora certificate of addition no.
`77 17625, filed on June 3rd 1977 and entitled “Data
`distribution system”.
`As this video-transmission system is thus widely 55
`known,it will not be described in detail here. Only the
`essential principles will be mentioned, to make the in-
`vention easier to understand. For any details of design
`or construction, reference can be made to the docu-
`ments cited above whichin turn refer to others, andall
`these documents should be regarded as incorporated in
`this description.
`FIG. 1 shows, in highly diagrammatic form, the es-
`sential elements of such a system. Such a system com-
`prises an emitting centre 2 and Tepniving stations 4, 4’,
`etc.
`The emitting centre receives infection from one or
`more sources 5 and comprises:
`
`20
`
`25
`
`30
`
`50
`
`60
`
`65
`
`which means that the magazine is transmitted cyclically
`with a periodicity of 4 seconds.
`It will be noted thatan interactive line connecting the
`distribution centre to the information supplier typically
`operates at 4800 b/s andthis difference in speed relative
`to the speed of broadcasting at 12800 b/s explains the
`need to memorise the information at the distribution
`source.
`
`In such system, the octets carrying the information
`are traditionally marked as follows:
`
`
`bs
`Odd-numbered
`
`k
`j
`—— a,
`Le b6 =
`by.b3 at
`High weight
`Low weight
`
`whereinthe binary element bg is an odd-numbered ele-
`ment, in other words an element wherein the total num-
`ber of “1” appearing in the octet is odd.
`‘
`Thus,
`according
`to this
`notation,
`the octet
`(j/k) =(4/7) correspondsto the octet 11000111.
`The octets are divided into control octets and data
`octets. The control octets indicate,
`in particular,
`the.
`beginnings and ends of pages and the beginnings and
`ends of lines. The data octets,
`inserted between the
`control octets, correspond to the characters contained
`
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`Apple v. PMC
`IPR2016-00753
`Page 11
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`

`4,337,483
`
`:
`
`b
`bo
`bs
`
`«60
`OF
`O
`
`COO
`080
`1
`
`1
`
`O
`1
`1
`
`Ff
`O
`o
`
`-F
`
`1
`
`i
`[:-
`0
`
`1
`J
`1
`
`3
`in the lines. All these octets, both control and data oc-
`tets, comprise a heavy weight binary element which is
`an odd-numbered element.
`All the codes, identified by such octets, are organised
`into a table as follows:
`
`4
`Nowthat these points regarding the general system
`have been mentioned, we can deal with the problem
`which the invention sets out to solve.
`The advent of the new services above mentioned
`raises the question of how to charge for them,i.e. how
`to implement a system for identifying and controlling
`the audiences. This question arises more generally for
`any broadcast service which tends to make the broad-
`casting networks more profitable by making better use
`of the resources.
`J
`
`by
`by)
`6bplSCOySCk
`Oo
`1
`2
`3
`4
`5
`6
`7F
`Taxation of the subscription type constitutes a both
`o
`o
`oOo
`oO
`0
`flexible and durable relationship between a service and
`o
`o
`oOo
`1
`1
`its users. Such a methodof taxation is particularly justi-
`o
`oOo
`41
`0
`2
`fied in broadcasting.
`oe
`OO
`=f
`ch
`3
`o0.UvUdtmCCCOULU
`Taxation of the type based on consumption mayalso
`
`
`
`
`ft Fd 21 8
`be used; this method oftaxation is fundamental for “in-
`teractive” systems (where there is a dialogue between
`the subscriber and the information source; however,it is
`In this table,
`of secondary value in broadcasting systems (in which
`the columns 0 and | which correspond to the octets
`information is transmitted in one direction to the sub-
`wherein the 6th and 7th binary elements are zero
`scribers).
`(bg=b7=0), contain control octets;
`There may be intermediate systems known as “quasi-
`columns 2 and 3 contain essentially numbers and
`interactive” systems wherein the contentof the distribu-
`punctuation marks;
`tion source is continuously modified to meet the re-
`columns 4 and 5 contain essentially capital letters,
`quirements of the users, which are transmitted via a
`columns6 and 7 chiefly contain lower case letters.
`public data network. The advent of new distribution
`As an example, a current page of information accessi-
`means with a very large capacity, such assatellites, will
`ble to the user is in the following form:
`develop this quasi-interactive mode considerably, thus
`(1) First, it contains a page heading, which is made up
`making it necessary to implement a system for control-
`of the control codes (ETX) FF RS NP; NP2 NP3:
`ling access to the information provided.
`wherein:
`This problem of access control raises above all the
`ETXis a code which terminates the preceding page,
`problems of encrypting the information when it
`is
`FFis a code indicating a new page,
`broadcast and decrypting whenit is received. Natu-
`RSis a pageflag,
`rally, these problems must be resolved in accordance
`NP\, NP2, NP3 are codes indicating a page number
`with the specificity of the teletext system whichis to be
`from 001 to 999,
`controlled. In particular, the method of scrambling the
`(2) After the page heading thereis a ‘‘zero” line: US
`information and restoring the intelligibility of the infor-
`00 C; C2 C3........ RC LF,
`mation should not harm the performanceof the system.
`wherein:
`Now,it is known that messages translated into the
`USis a line flag,
`suitable language are characterised by a substantial
`00 indicates the zeroline,
`redundancy so that the incidence of transmission errors
`C1, C2, C3 are supplementary codes,
`on the intelligibility of the information broadcast
`is
`RC LFterminate the line.
`minimised. Thus, alphabetic texts are intrinsically very
`The zero line mayalso contain an operating name, a
`redundant, as are the majority of semi-graphic draw-
`date, a time and optionally information on charges. This
`ings;
`the character display controls use escapement
`zero line does not carry any information which consti-
`characters; the page and line numbering uses Hamming
`tutes the service. It is part of the procedure.
`codes; all the octets constituting a magazine are trans-
`(3) After the zero line come the information lines
`mitted with imparity, etc. ... Thus, there is no attempt
`comprisingfirst ofall a line heading which is made up of
`to compress the information and the methodof recover-
`ing the intelligibility of the information must therefore
`the codes (RC LF) US NR; NR2, wherein:
`respect this redundancy and not propagatethe deleteri-
`RC LFterminate the previous line,
`ous consequences of transmission errors, which are
`USisalineflag,
`difficult to monitor in broadcasting.
`NR; NR2constitute the line number, which goes
`from 01 to 24.
`The means for recovering the intelligibility of infor-
`Then comethe data octets d}, d2...d,. These octets are
`mation which has been locked up beforehand consti-
`inserted between thestart of the currentline and either
`tute, to some extent, an “electronic lock”, and theintel-
`ligibility of the locked up information can only be re-
`a line end—start of new line - or the end of a page.
`These octets dj, dz, ... dy represent the information
`covered by the use ofa suitable key.
`The first question whicharises is therefore the room
`constituting the service being broadcast. Thusthe infor-
`to be allotted to this electronic lock in the system to be
`mation element in a system ofthis kind is the displayable
`line.
`monitored. In fact,
`in the case of the teletext system,
`There are also other pages in addition to these current
`two procedures are used: the transporting procedure
`and the operating procedure. At whatlevelof the pro-
`pages of information. They are functionally accessible
`cedure should this lock be placed?
`by means of the supplementary codes Cy, C2, C3 con-
`tained in the zero line. These are, for example, cover
`BRIEF SUMMARY OF THE INVENTION
`sheets and warning pages. All these pagesare part of the
`procedure. Finally, there is a page of summary which
`can be regarded as part of the data.
`
`40
`
`50
`
`65
`
`The invention answers this question by proposing a
`lock which is attached to the operating level. This
`
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`Apple v. PMC
`IPR2016-00753
`Page 12
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`4,337,483
`
`25
`
`30
`
`45
`
`20
`
`6
`5
`and the group of columns 6 and 7 which contains
`method has a numberof advantages.First, it respects all
`mainly lower case letters.
`the constraints of synchronisation and non-propagation
`Finally, the octets belonging to columns 0 and | are
`of the transmission errors. Furthermore,it is indepen-
`not modified, particularly the octets corresponding to
`dent of the transporting network used by the system.
`the codes ETX, FF, RS, RC, LF and US, which are
`Finally, it does not require any adjustment of the exist-
`transmitted as they stand. Moreover, owing to the fact
`ing standards and will accommodate any future devel-
`that the 6th and 7th binary elements of the encoding
`opmentof these standards.
`In other words, and accordingto a first feature of the
`octets are zero, no new octets belonging to these col-
`umns are introduced. Thus the desires transparencyis
`invention, the encryption of the information constitut-
`ensured.
`ing a magazineis carried outat the distribution source.
`In this way,all the aims listed ne are attained with
`More precisely, the encryption means are located up-
`the locking means used according to the invention.
`stream of the multiplexer, which has reference numeral
`To reinforce the inviolability of the lock thus formed,
`12 in the plan in FIG.1.
`Now that room has been found for the encryption
`the operating key K is advantageously modified at ran-
`dom at predetermined,relatively short intervals (of the
`means,thereis still the question of the object to which
`order of a few minutes, for example).
`these means are applied.
`It then remains to decrypt the information whenit is
`The invention answers this second question by pro-
`posing means whose function is to encrypt up only the
`received. To do this, the receiver should comprise a
`generator of decoding octets which delivers octets
`information carried in the displayablelines of the ordi-
`formed as follows:
`nary pages of the magazine. In other words, the encryp-
`tion does not affect the control codes appearing in col-
`the low weight 5th binary elements are taken from a
`umns 0 and 1 ofthe table of codes given hereinbefore
`quasi-random series obtained from a generator reset at
`eachstart of a line by the operating key K, by the page
`and,in particular, the codes ETX, FF, RS, RC, LF and
`and line numbers in question;
`US.It affects only the data codes dj, d2, etc. This is the
`second feature of the invention.
`the 6th and 7th binary elements are zero, and
`the 8th binary elementis forced to zero.
`Finally, the invention sets out to solve a third prob-
`lem, that of respecting the imparity of the octets broad-
`The rules for decryption are analogous to the rules
`cast.
`for encryption; at each new octet received, belonging to
`an encrypted line, a new decoding octet is generated.
`All these aims are achieved by the use, according to
`There are twopossibilities:
`the invention, of automatic encryption means which
`If the octet received belongs to columns 0 and1, it is
`comprise means for forming a succession of encoding
`transmitted as it stands to the interpreting circuits;
`octets wherein the binary elements marked cj to cg are
`If the octet received does not belong to columns 0
`generated as follows:
`and 1 (because its 6th and/or 7th binary elements are
`C1, C2, C3, cgand csare taken at the output of a pseudo-
`not zero) it is combined by an OR-exclusivecircuit with
`random series generator which is reset at the start of 35
`the decoding octet before interpretation is carried out.
`each displayable line by an operating key K and by the
`Interpretation of the language is thus closely inter-
`page and line numbers in question;
`connected to the encryption ofthelines of information,
`cg and c7 are at zero, and
`and the robustness of the structure of the language
`cg is an even-numbered element.
`broadcast is not affected by the encryption operations.
`Thus, the coding series obtained is made up of even
`Now that these general comments have been made
`octets. These octets are marked C), C2... C,, or, generi-
`regarding the invention, the precise definition of the
`cally, Cj. The clear octets constituting a line of informa-
`object of the invention can then be wordedas follows:
`tion form a series marked d,, dz... d, or, generi-
`cally, dj. These octets are odd-numbered and are
`Transmission system comprising an information emit-
`locked wD by the encoding octets in accordance with
`ting centre and receiving stations, the emission centre
`the following rules:
`comprising:
`means 6 for composing a magazine consisting of
`At each new clear octet of the displayable line, an
`pages organised into lines of characters, if such means
`octet is taken from the encoding series. There are two
`are not already contained in the information source,
`possibilities:
`acircuit 10 for memorising the magazine in the form
`If the clear octet belongs to columns 0 and 1 of the
`of numerical signals grouped in octets (8 binary ele-
`table of codes (bg =b7=0)the clear octet is transmitted
`ments), these octets comprising control octets and data
`as it stands, and the encoding octet is not used;
`octets, the control octets indicating in particular the
`If the clear octet does not belong to column 0 or1,
`beginnings and ends of pages and the beginnings and
`then the clear octet and the encoding octet are com-
`endsoflines, the data octets corresponding to the char-
`bined by an “OR-exclusive” logic circuit
`to form a
`acters contained in each line, all these control and data
`broadcast octet: Dj=djC;, where the symbol © repre-
`octets comprising a binary element of high weight
`sents the “OR-exclusive” logic operation.
`which is an odd-numbered element, the octets wherein
`the
`Because of the parity of the encoding octets,
`broadcast octets are odd,
`like the clear octets, thus
`the 6th and 7th binary elements are zero being control
`octets,
`satisfying the requirement mentioned above.
`Moreover,
`the “OR-exclusive” operation is mani-
`a junction 11 connected to the circuit 10, and
`a distribution multiplexer 12 serving to insert infor-
`fested by the substitution of the clear octet by a broad-
`mation in the lines of a television signal, this emitting
`cast octet belonging to the same group of columns as
`centre also comprising meansfor encoding the informa-
`the clear octet, namely:
`tion using an operating key, each receiving station com-
`the group of columns 2 and 2 which contains essen-
`prising:
`tially the numbers and punctuation marks,
`a circuit 14 for receiving and demodulating said tele-
`the group of columns 4 and 5 which contains mainly
`vision signal,
`capital letters,
`
`55
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`65
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`PMC Exhibit 2091
`Apple v. PMC
`IPR2016-00753
`Page 13
`
`PMC Exhibit 2091
`Apple v. PMC
`IPR2016-00753
`Page 13
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`4,337,483
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`20
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`io
`a line 16 for processing the video picture signals,
`a line 18 for processing numerical signals, containing
`in particular a numerical signal decoder, and
`display means20, each receiving station further com-
`prising means for decoding the coded information using
`said operating key, the system being characterised in
`that:
`(A) the encoding means of the emission centre com-
`prise:
`(a) a generator 22 delivering a numerical signal repre-
`senting an operating key K,this key changing randomly
`at predetermined intervals,
`(b) automatic encryption means 24 comprising:
`(i) a discriminator with an input connected to the
`magazine memorising circuit from which it receives
`clear octets, this discriminator being adapted to distin-
`guish, amongthese clear octets, those wherein the 7th -
`and 6th binary elements are zero,
`this discriminator
`having two outputs,
`the first carrying these octets
`wherein the 7th and 6th binary elements are zero, and
`connected to the distribution multiplexer through the
`Junction, and the second carrying the clear octets d;
`wherein the 7th and/or 6th binary elements are not
`zero,
`(ii) an OR-exclusivelogic circuit with two inputs, one
`of which is connected to the second output ofthe dis-
`criminator from which it receives the clear octets dj
`wherein the 6th and/or 7th binary elements are not
`zero, this logic circuit having an output which carries
`odd-numbered coded octets Dj, the coded octets then
`_ being directed towards the distribution multiplexer
`through the junction;
`(c) a generator of encoding octets controlled by the
`automatic encryption means from which it receives
`octets indicating the page and line numbersofthe data
`to be transmitted and the signal corresponding to the
`operating key, this generator of octets delivering, for
`each data octet dj of a displayable line, an encrypted
`octet Cj, this octet having an even-numbered 8th binary
`element and 7th and 6th binary elements of zero, this
`octet being applied to the other input of the logic cir-
`cuit,
`(B) the decoding means of each receiving station
`comprise:
`(d) a generatorof a numerical signal representing the
`current operating key K in the emitting centre,
`(e) automatic decryption means comprising:
`(i) a discriminator with an input connected to the
`numerical signal decoderof the receiving station, from
`which it receives the coded octets, this discriminator
`being adapted to distinguish, among these coded octets,
`those wherein the 7th and 6th binary elements are zero,
`this discriminator having two outputs,thefirst carrying
`these octets wherein the 7th and 6th binary elements are
`zero, this first output being directly connected to the
`display means, the second carrying the coded octets D;
`wherein the 7th and/or 6th binary elements are not
`zero,
`(ii) an OR-exclusive logic circuit with two inputs, one
`connected to the second output of the discriminator
`from which it receives the coded octets Dj, this logic
`circuit having an output which carries decoded octets
`dj which are then directed towards the display means;
`(f) a generator of decoding octets controlled by the
`automatic decryption means which transmits to it the
`octets indicating the page and line numbers of the data
`transmitted and the signal corresponding to the current
`operating key K,
`this generator of decoding octets
`
`having an output which delivers, for each encrypted
`octet received, a decoding octet C; having a high
`weight binary element whichis forced to zero and 7th
`and 6th binary elements of zero.
`Encryption and decryption means ofthis kind pro-
`vide an advantageous solution to the problem of charg-
`ing mentioned hereinbefore. For this purpose, the in-
`vention proposes that in addition to the operating key
`whose function has been defined above, subscribers’
`keys should be used, which are generated randomly by
`a charge administration centre. These keys havea rela-
`tively long servicelife (from 1 to 12 months), compared
`with the operating key (which is of the order of a few
`minutes),
`:
`To illustrate the functioning of this double key sys-
`tem, one could take the example of a subscription plan
`using four types of subscription: 1 month, 3 months, 6
`months and one year. In addition to its duration, a sub-
`scription is characterised by the month in whichit be-
`gins. With a plan ofthis kind, in a given month and for
`a given service, there are thus 22 subscribers’ keysliable
`to be used by the users: a monthly key, three three-
`monthly keys, six six-monthly keys and twelve yearly
`keys.
`Each month, the charge administration centre pro-
`vides each distribution centre with a list of 22 subscrib-
`ers’ keys in use for each service distributed by this cen-
`tre. It also provides the subscription sales points with
`anotherlist of 4 keys which areto start in the following
`month (one month,
`three months, six months and a
`year), for each service, with the prices of the subscrip-
`tions.
`A suitable machine installed in each sales point re-
`cords someof these keys, in the form of subscription
`blocks, on holders provided for this purpose (for exam-
`ple, information-bearing cards of the credit card type).
`These cards are then inserted by theusers of the service
`in the receiver.
`For each chargeable service, approximately every
`five minutes, a new operating key K is generated at
`random,by eachdistribution centre concerned. Thus,in
`the course ofa session of a service (one or more hours),
`several dozen operating keys may succeed one another.
`As soonas a distribution centre generates a new oper-
`ating key K,it calculates, for each current subscribers’
`key in use C;for this service, a message M; by means of
`an algorithm M;=Fc; (K), with the keys C; acting as
`parameters.
`Thus, for a service using the subscription plan de-
`scribed above, there are 22 different messages in force at
`any one time. The duration of a messageis equal to that
`of the operating key K, and for a given service, at any
`one time, there are as many messagesas there are sub-
`scribers’ keys in use.
`All the messages M; in force together constitute the
`information for access control associated with the ser-
`vice being broadcast. This access control information is
`obviously not locked up by the electronic lock.
`A particular application of this system is envisaged
`within the scope of the present invention. In this in-
`stance, the messages Mj are grouped in a special page,
`known as the access control page, which is updated
`each time the operating key is changed. The access
`control pageis distributed cyclically, like the ordinary
`pages of information constituting the service. However,
`it is not locked up by the electronic lock. The access
`control page is read systematically by the receiver
`whenit is put into contact with the service, then each
`
`PMC Exhibit 2091
`Apple v. PMC
`IPR2016-00753
`Page 14
`
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`35
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`PMC Exhibit 2091
`Apple v. PMC
`IPR2016-00753
`Page 14
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`

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`4,337,483
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`9
`time this page is updated, during the period of consulta-
`tion ofthe service, but it is not displayable.
`The messagesare therefore, in fact, motifs of primary
`synchronisation of the lock and these motifs can be
`interpreted by an algorithm supplying the operating
`key. This algorithm is in the form: K=Gc; (M4,and is
`developed by a restoring circuit (which may also be
`part of the subscription holder which already contains
`the subscribers’ key C,) to which the messages M;are
`supplied. This circuit therefore provides the automatic
`unlocking means with the operating key K which ena-
`bles it to unlock the information received.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`10
`According, to the invention,the system also. com-
`prises:
`(A) in the emitting centre 2:-
`.
`- 3).
`is
`(a)a generator 22 delivering a numerical signal repre-
`’
`senting an operating key K, this key changing randomly
`at predetermined intervals which are, for example, of
`the order of a few minutes;
`(b) automatic encryption means 24 comprising:
`(i) a discriminator 28 with an input connected to the
`magazine memorising circuit 10 from which it receives
`clear octets; this discriminator is adapted to distinguish,
`amongthese clear octets, those wherein the 7th and 6th
`binary elements are zero; this discriminator has two
`outputs 31 and 32,
`the first carrying these octets
`In any case, the features and advantagesofthis inven-
`wherein the 7th and 6th binary elements ar