US3808365A - Method and apparatus for encoding and decoding messages - Google Patents

Method and apparatus for encoding and decoding messages Download PDF

Info

Publication number
US3808365A
US3808365A US00205098A US20509871A US3808365A US 3808365 A US3808365 A US 3808365A US 00205098 A US00205098 A US 00205098A US 20509871 A US20509871 A US 20509871A US 3808365 A US3808365 A US 3808365A
Authority
US
United States
Prior art keywords
pulses
series
time
pulse
clock
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00205098A
Other languages
English (en)
Inventor
K Ehrat
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Gretag AG
Original Assignee
Gretag AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Gretag AG filed Critical Gretag AG
Application granted granted Critical
Publication of US3808365A publication Critical patent/US3808365A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
    • H04L9/12—Transmitting and receiving encryption devices synchronised or initially set up in a particular manner
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
    • H04L9/06—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols the encryption apparatus using shift registers or memories for block-wise or stream coding, e.g. DES systems or RC4; Hash functions; Pseudorandom sequence generators
    • H04L9/065—Encryption by serially and continuously modifying data stream elements, e.g. stream cipher systems, RC4, SEAL or A5/3
    • H04L9/0656—Pseudorandom key sequence combined element-for-element with data sequence, e.g. one-time-pad [OTP] or Vernam's cipher
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L2209/00—Additional information or applications relating to cryptographic mechanisms or cryptographic arrangements for secret or secure communication H04L9/00
    • H04L2209/12—Details relating to cryptographic hardware or logic circuitry

Definitions

  • Thei rigding data is derive om a secret asic co e an e output coding
  • Appl' 205098 pulses from the pulse generator are used to encode clear message pulses, the encoded message then being [30] Foreign Application Priority Data transmitted to a receiving station.
  • the encoded mes- Dec. 8 1970 Switzerland 18134/70 e is deemed by mixing with mdinfilqlieil' **d in the same way as the coding pulse were pro- 52 US. Cl. 178/22 prised by the generamrl Means are Provided [51] Int. Cl.
  • H04l 9/02 Synchronismg the generation of the coding Pulses at 58 Field of Search 178/22 the transmiting and receiving smimls-
  • the rules forming the coding pulse sequences are selected so [56] References Cited that these sequences depend only for a limited period of time on the state of their terms at the beginning of UNITED STATES PATENTS that period of time.
  • PATENTEDAPR 30 I974 sum 01 or 18 PATENTEDAPR 30 m4 sum 02 0F 18 llll-ll llll NQW w E2: 2104 nmkm b2 ER Nt DNv N55: 9
  • PATENTEDAPR 30 I974 sum 10 UF18 PATENTEDAPR 30 1974 sum 12 or 18 FIG. l
  • PATENTEDAPR 30 I974 sum-1s or 18 $66 I 855KB ms;
  • PATENTEDAPR 30 I974 sum '17 [1F 18 llo PATENTEDAPR 30 1974 3808.365
  • This invention relates to a method for the encoded transmission of messages in which the clear language message pulses are mixed on the transmitting side with coding .pulses and the clear message pulses are restored on the receiving side by mixing the received coded pulse train with identical coding pulses, the coding pulses being generated at the transmitting and receiving stations by identical pulse generators in accordance with identical rules based on a secret basic code and a term derived from the date and time.
  • the rules for forming the coding pulse sequences are selected so that they depend on the initial state of coding pulse generators, the initial state itself being defined by basic and supplementary codes. Since the coding pulse generators are set to a new initial state for each new message transmission it is impossible even for authorised third parties to gain access to a connection which is already established and over which a coded message is being transmitted. This is a disadvantage, in particular in multiple transmission networks.
  • the invention seeks to avoid this disadvantage by forming the coding pulse sequences in accordance with rules selected so that the last mentioned sequence depends only for a limited period of time on the condition of its terms at the beginning of the said period of time and that the instantaneous state of the data contained in all the storage cells of the coding pulse generator is constantly influenced by the term derived from the data and time, at least during message transmission.
  • the initial state of the coding pulse generators is no longer preset, instead the instantaneous state of the data in the storage cells of the coding pulse generator are constantly influenced by a term derived from the date and time, that is to say the initial state of the coding pulse generator is constantly reset.
  • the rules for forming the coding pulse sequences are selected so that these sequences depend only for a limited period of time on the state of their terms at the beginning of the said period of time. This means that the initial data produced by the coding pulse generator at an instant in time depends only on the input data which occurs during a predetermined period of time prior to that instant and is independent of all input data applied earlier.
  • An authorised third party may without difficulty gain access to an existing encoded message transmission since he need only wait for those moments in time at which the coding pulse sequence which occurs at the output of the coding pulse generator at the transmitting station is independent of the secret and supplementary coding states occuring prior to the aforementioned moments in time and in which the instantaneous state of the coding pulse generator is influenced by the term derived from the date and time.
  • This invention furthermore provides apparatus for performing the aforementioned method, the apparatus having a clock, preferably electronic, and a coding pulse generator which may be driven by a control pulse sequence formed from a secret basic code and from a term derived from the date and time.
  • the coding pulse generator may be programmed so that each coding pulse at the output of the coding pulse generator remains unaffected by that part of the control pulse sequence which occurs prior to the affected coding pulse by an amount of time equal to the so-called passage time and that the passage time switches from a larger to a smaller value for a predetermined period of time and at intervals which depend on the secret code.
  • the clock is connected as a timing generator for the coding pulse generator.
  • FIG. 1 is a block diagram of a coding apparatus.
  • FIGS. 2a and 2b are details of FIG. 1.
  • FIGS. 3 to 6 are graphs illustrating the pulses used in synchronising two sets of coding apparatus.
  • FIGS. 7, 8 illustrate detail modifications of FIG. 1.
  • FIGS. 9, 10 are diagrams showing the function of synchronising sets of coding apparatus.
  • FIGS. 11, 12 are detail variations of FIG. 1.
  • FIGS. l3, 14 are diagrams for explaining the synchronising stage illustrated in FIG. 12, and
  • FIGS. 15 to 20 show detail variations of FIG. 1.
  • each coding station is provided with a clear language text-clear language pulse converter 9, the converter being adapted to convert the clear language message text into clear language message pulses at the transmitter or vice versa at the receiver.
  • This converter may be, for example, a teleprinter.
  • the output of the transmitter station converter feeds the clear language message pulses through a conductor 147 into a mixer 8 the output of which is connected to the transmission line 148, which may be a cable, wire or radio link.
  • the transmission line 148' is connected to a mixer 8 the output of which feeds a converter 9 through a conductor 102.
  • the mixer 8 is provided with encoding pulse sequences from coding apparatus which are mixed in the transmitter station mixer with the clear language message pulse sequences generated by the clear language text-clear language pulse converter 9.
  • the pulse sequences thus encoded and received on conductor 148 are mixed with decoding pulse sequences identical to the encoding pulse sequences and fed to the clear language text-clear language pulse converter at the receiving station which restores the received encoded pulse sequences to the clear language message text.
  • the coding apparatus mainly comprises an encoding pulse generator 5 and a synchronising stage 6.
  • the purpose of the coding pulse generator 5 is to produce a coding pulse sequence with the longest possible cycle and which is built up in such a way that variation between successive elements or element groups is as random as possible.
  • the coding pulse generator comprises

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Synchronisation In Digital Transmission Systems (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Storage Device Security (AREA)
US00205098A 1970-12-08 1971-12-06 Method and apparatus for encoding and decoding messages Expired - Lifetime US3808365A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH1813470A CH540613A (de) 1970-12-08 1970-12-08 Verfahren und Vorrichtung zur chiffrierten Nachrichtenübermittlung

Publications (1)

Publication Number Publication Date
US3808365A true US3808365A (en) 1974-04-30

Family

ID=4430724

Family Applications (1)

Application Number Title Priority Date Filing Date
US00205098A Expired - Lifetime US3808365A (en) 1970-12-08 1971-12-06 Method and apparatus for encoding and decoding messages

Country Status (8)

Country Link
US (1) US3808365A (fr)
CA (1) CA956891A (fr)
CH (1) CH540613A (fr)
DE (1) DE2160132A1 (fr)
FR (1) FR2117478A5 (fr)
GB (1) GB1379740A (fr)
IT (1) IT943759B (fr)
SE (1) SE378496B (fr)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4107458A (en) * 1976-08-23 1978-08-15 Constant James N Cipher computer and cryptographic system
US4133973A (en) * 1976-11-10 1979-01-09 Datotek, Inc. Digital cryptographic system having synchronous and asynchronous capabilities
US4166922A (en) * 1975-04-14 1979-09-04 Datotek, Inc. Multi-mode digital enciphering system with repeated priming sequences
EP0050268A1 (fr) * 1980-10-16 1982-04-28 Siemens Aktiengesellschaft Dispositif pour la transmission chiffrée d'informations
EP0131663A1 (fr) * 1983-07-13 1985-01-23 Sony Corporation Appareil pour brouiller un signal de télévision
WO1985004299A1 (fr) * 1984-03-14 1985-09-26 Computer Security Systems, Inc. Procede et appareil pour proteger des donnees memorisees et tansmises d'une egalisation fixe ou d'une interception
EP0206319A2 (fr) * 1985-06-25 1986-12-30 Nec Corporation Circuit de codage et de décodage de données
EP0209079A2 (fr) * 1985-07-12 1987-01-21 Siemens Aktiengesellschaft Procédé de réalisation d'une communication radio chiffrée
EP0258838A2 (fr) * 1986-09-01 1988-03-09 Siemens Aktiengesellschaft Dispositif pour l'actualisation du temps local d'un utilisateur d'un système de transfert d'informations
US4747139A (en) * 1984-08-27 1988-05-24 Taaffe James L Software security method and systems
US4972474A (en) * 1989-05-01 1990-11-20 Cylink Corporation Integer encryptor
US20050195887A1 (en) * 2003-10-21 2005-09-08 Mitsubishi Denki Kabushiki Kaisha System and device for modulating UMB pulse sequences
US7577188B1 (en) * 2001-09-13 2009-08-18 Cisco Technology, Inc. Physical layer and MAC enhancements using complex sequences on a wireless channel
CN106533529A (zh) * 2016-09-27 2017-03-22 北京无线电计量测试研究所 一种卫星双向时间比对的调制解调系统与方法

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2448824A1 (fr) * 1979-02-06 1980-09-05 Telediffusion Fse Systeme de videotex muni de moyens de controle d'acces a l'information
FR2448825A1 (fr) * 1979-02-06 1980-09-05 Telediffusion Fse Systeme de transmission d'information entre un centre d'emission et des postes recepteurs, ce systeme etant muni d'un moyen de controle de l'acces a l'information transmise
JPS6120442A (ja) * 1984-07-09 1986-01-29 Toshiba Corp 有料放送方式
DE3730134C1 (de) * 1987-09-09 1996-05-30 Siemens Ag Schlüsselgerät

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3170033A (en) * 1960-08-02 1965-02-16 Csf Electrical generators of quasi-random symbols
US3427399A (en) * 1964-11-06 1969-02-11 Ciba Ltd Method of and apparatus for encoding and decoding clear signal pulse sequences
US3614316A (en) * 1964-05-20 1971-10-19 Us Navy Secure communication system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3170033A (en) * 1960-08-02 1965-02-16 Csf Electrical generators of quasi-random symbols
US3614316A (en) * 1964-05-20 1971-10-19 Us Navy Secure communication system
US3427399A (en) * 1964-11-06 1969-02-11 Ciba Ltd Method of and apparatus for encoding and decoding clear signal pulse sequences

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4166922A (en) * 1975-04-14 1979-09-04 Datotek, Inc. Multi-mode digital enciphering system with repeated priming sequences
US4107458A (en) * 1976-08-23 1978-08-15 Constant James N Cipher computer and cryptographic system
US4133973A (en) * 1976-11-10 1979-01-09 Datotek, Inc. Digital cryptographic system having synchronous and asynchronous capabilities
EP0050268A1 (fr) * 1980-10-16 1982-04-28 Siemens Aktiengesellschaft Dispositif pour la transmission chiffrée d'informations
EP0131663A1 (fr) * 1983-07-13 1985-01-23 Sony Corporation Appareil pour brouiller un signal de télévision
WO1985004299A1 (fr) * 1984-03-14 1985-09-26 Computer Security Systems, Inc. Procede et appareil pour proteger des donnees memorisees et tansmises d'une egalisation fixe ou d'une interception
US4747139A (en) * 1984-08-27 1988-05-24 Taaffe James L Software security method and systems
EP0206319A2 (fr) * 1985-06-25 1986-12-30 Nec Corporation Circuit de codage et de décodage de données
EP0206319A3 (fr) * 1985-06-25 1988-05-04 Nec Corporation Circuit de codage et de décodage de données
EP0209079A3 (en) * 1985-07-12 1989-01-04 Siemens Aktiengesellschaft Berlin Und Munchen Method for making an enciphered radio communication
EP0209079A2 (fr) * 1985-07-12 1987-01-21 Siemens Aktiengesellschaft Procédé de réalisation d'une communication radio chiffrée
EP0258838A2 (fr) * 1986-09-01 1988-03-09 Siemens Aktiengesellschaft Dispositif pour l'actualisation du temps local d'un utilisateur d'un système de transfert d'informations
EP0258838A3 (fr) * 1986-09-01 1991-01-23 Siemens Aktiengesellschaft Dispositif pour l'actualisation du temps local d'un utilisateur d'un système de transfert d'informations
US4972474A (en) * 1989-05-01 1990-11-20 Cylink Corporation Integer encryptor
US7577188B1 (en) * 2001-09-13 2009-08-18 Cisco Technology, Inc. Physical layer and MAC enhancements using complex sequences on a wireless channel
US20050195887A1 (en) * 2003-10-21 2005-09-08 Mitsubishi Denki Kabushiki Kaisha System and device for modulating UMB pulse sequences
US7539234B2 (en) * 2003-10-21 2009-05-26 Mitsubishi Denki Kabushiki Kaisha System and device for modulating UWB pulse sequences
CN106533529A (zh) * 2016-09-27 2017-03-22 北京无线电计量测试研究所 一种卫星双向时间比对的调制解调系统与方法
CN106533529B (zh) * 2016-09-27 2020-03-03 北京无线电计量测试研究所 一种卫星双向时间比对的调制解调系统与方法

Also Published As

Publication number Publication date
IT943759B (it) 1973-04-10
SE378496B (fr) 1975-09-01
GB1379740A (en) 1975-01-08
FR2117478A5 (fr) 1972-07-21
CA956891A (en) 1974-10-29
DE2160132A1 (de) 1972-06-22
CH540613A (de) 1973-08-15

Similar Documents

Publication Publication Date Title
US3808365A (en) Method and apparatus for encoding and decoding messages
US4145568A (en) Method and apparatus for ciphering and deciphering messages
US3523291A (en) Data transmission system
US2498695A (en) Telegraph receiver
US4341925A (en) Random digital encryption secure communication system
US4145569A (en) Method and apparatus for synchronizing the ciphering and deciphering of binary-coded messages
RU95105525A (ru) Приемная и передающая аппаратура и способ, включающий пунктурированное сверточное кодирование и декодирование
US3038028A (en) Arrangement for producing a series of pulses
US3852534A (en) Method and apparatus for synchronizing pseudorandom coded data sequences
JPS6336589B2 (fr)
GB1388035A (en) Method of and apparatus for encoded communications transmission
FR1442912A (fr) Dispositif de codage d'une information ayant la forme d'impulsions
US3603932A (en) Party line stations for selective calling systems
US3813493A (en) Secure data transmission apparatus
DE1076733B (de) Anordnung zur Sicherstellung des Synchronlaufs der Schluessel-zeichengeneratoren aufder Sende- und Empfangsseite bei der Geheimuebertragung von kodierten Nachrichtensignalen
US4093940A (en) System and equipment for quality checking of a digital connection circuit
US2858530A (en) Conversion of binary code to reflected code
US4007422A (en) Method and apparatus for calling a ground station by an aircraft
SU370737A1 (ru) Всесоюзная .
US4156115A (en) Apparatus and method for a multiple tone code sender system for automatic call initiation
US4177485A (en) Facsimile apparatus
US2509829A (en) Duplex telegraph system
RU2206957C2 (ru) Устройство приема дискретной информации
SU1181572A3 (ru) Устройство вызова наземной станции с самолета
JPS5449002A (en) Secret communication system