EP0204226B1 - Procédé de réalisation d'une communication radiophonique chiffrée - Google Patents

Procédé de réalisation d'une communication radiophonique chiffrée Download PDF

Info

Publication number
EP0204226B1
EP0204226B1 EP86106999A EP86106999A EP0204226B1 EP 0204226 B1 EP0204226 B1 EP 0204226B1 EP 86106999 A EP86106999 A EP 86106999A EP 86106999 A EP86106999 A EP 86106999A EP 0204226 B1 EP0204226 B1 EP 0204226B1
Authority
EP
European Patent Office
Prior art keywords
information
procedure
station
identification
cipher
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
EP86106999A
Other languages
German (de)
English (en)
Other versions
EP0204226A2 (fr
EP0204226A3 (en
Inventor
Bodo Dipl.-Math. Rittenauer
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.)
Siemens AG
Original Assignee
Siemens 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 Siemens AG filed Critical Siemens AG
Priority to AT86106999T priority Critical patent/ATE55523T1/de
Publication of EP0204226A2 publication Critical patent/EP0204226A2/fr
Publication of EP0204226A3 publication Critical patent/EP0204226A3/de
Application granted granted Critical
Publication of EP0204226B1 publication Critical patent/EP0204226B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
    • H04K1/00—Secret communication

Definitions

  • the invention relates to a method for carrying out encrypted radio traffic between transmitting and receiving stations, in particular mobile transmitting and receiving stations, in which time-dependent synchronization and identification information is transmitted from the transmitting side to the receiving side at the beginning of at least certain transmission processes between at least two stations.
  • the individual transceiver stations In order to achieve a high level of secrecy for the information to be transmitted, it is customary, as is shown for example in the reference DE-OS 21 60 132, to transmit the information on the digital level and to encrypt the digital information in a suitable manner with a key signal sequence.
  • the individual transceiver stations In order to enable orderly radio traffic for this, the individual transceiver stations must use the same day key on the one hand and also work synchronously.
  • the key signal sequence is derived from the time, a code number and the day key, and time-dependent synchronization and identification information is transmitted at the start of the encrypted transmission.
  • the start phase address and start time information are transmitted here unencrypted as a preamble in order to give the receiving station the opportunity to generate the associated key signal sequence for decrypting the received message.
  • An intelligent jammer has the option here of recording a radio message to send it out again after an arbitrary time and in this way to update an already outdated and outdated information for the receiving stations. This can create considerable confusion within such a radio network.
  • a corresponding possibility for such an intrusion of an intelligent interferer into a radio network is given when a transceiver wants to access a synchronized radio network and, in plain text, requests the information required for its synchronization from a master station.
  • a transceiver wants to access a synchronized radio network and, in plain text, requests the information required for its synchronization from a master station.
  • the object of the invention is to eliminate the disadvantages of the older proposal for preventing intelligent intruders from penetrating into the radio network for radio systems operating with encryption.
  • process identifiers represent a key-related information derived from a received identifier information and exclusively marking the relevant transmission process.
  • the process identifiers differ from one another in terms of station and additionally regardless of whether a different key is always used for the successive connections between two transmitting / receiving stations Application comes.
  • a special embodiment of the method according to the invention for use in radio systems using preamble synchronization in connection with encryption is specified in claim 2.
  • a further advantageous application of the method for carrying out an initial synchronization of a station to a synchronized radio network having a master station and operating with encryption is in claim 3 wrote and specified a special embodiment thereof in claim 4.
  • a sequence control AST is provided for controlling the function of the key signal generator SSG, the characteristic value generator KWG and the switch U.
  • the key signal generator SSG has a basic key generator SG, which is adjustable and generates the day key.
  • the day key storage R1 is connected to the basic key generator SG, in which the day key is stored and can be called up as required.
  • the key signal generator SSG has the key computer SR, to the input side of which the mixer MD1, for example a modulo-2 adder, supplies a mixed signal from the day key and the signal supplied by the characteristic value transmitter. From this signal, the key computer SR generates the key signal sequence which is fed to the key sequence memory SF connected downstream.
  • the characteristic value generator KWG has a clock center TK, which on the one hand supplies the clock T for the various assemblies and also has a station clock, the accuracy of which is determined by the oscillation of the quartz generator G.
  • the clock center TK is connected to a station clock setting device EV controlled by the sequence control AST for setting the station clock.
  • the respective time is output in digital form from the clock center TK to the characteristic value memory R2 connected downstream.
  • the characteristic value memory R2 is also connected to an adjustable code number transmitter NE, the set code number of which is also stored in the characteristic value memory.
  • the signal from the KWG parameter transmitter to the mixer MD1 thus consists of the station time and a code number.
  • the request signal Sig to be emitted via the transmitter S of this transceiver station is first processed from the digital sequences called up via the day key memory R1 and the characteristic value memory R2 in the mixer MD1 into a mixed signal, from which the key computer SR then uses the day key, the time and the Code number-related key signal sequence generated and made available via the key sequence memory SF.
  • the request signal Sig begins with the switch U in the position shown caused by the sequential control AST, the time and the code number are sent to the transmitter S as a clear signal, and a key sequence pattern follows after switching the switch U into the switch position shown in broken lines.
  • the request signal generated in this way is sent unencrypted via the transmitter to the master station.
  • the evaluation of the request signal Sig sent by the station requesting synchronization and received by the master station will now be explained in more detail.
  • the key signal generator SSG and the characteristic value generator KWG corresponding to FIG. 1 are only shown in one block in FIG. 2.
  • the request signal fed to the receiver E via the antenna A and the transceiver W is divided into its individual components in the receiver E.
  • the characteristic value signal containing the time and the code number is fed to the key signal generator SSG via the switch U1 in the interrupted switch position, which generates the key signal sequence corresponding to the transmitting station after mixing with the day key in the mixer MD1 via the key computer SR and via the key sequence memory SF provides.
  • the key signal sequence generated in this way is fed to the key sequence pattern memory SF1 in the switching position shown via the changeover switch U3.
  • the receiver E feeds the key sequence pattern contained in the received request signal to the key sequence pattern memory SF2 via a second output line.
  • the conformity of the two key sequence patterns is then checked via the sequential control AST using the comparator V1.
  • the master station does not respond. If the result is negative, the master station does not respond. If the result is positive, the sequence control AST causes a characteristic portion of the key sequence pattern stored in the key sequence pattern memory SF2 is transferred to the key sequence sequence pattern memory SF3. At the same time, the key part sequence circulation memory SF4 is activated. For this purpose, the changeover switch U2 is brought into the switch position shown in an interrupted manner so that the key partial sequence patterns stored in the key partial sequence circulation memory SF4 can circulate. These key partial sequence patterns stored here are now compared via the comparator V2 with the characteristic part of the key sequence pattern stored in the key partial sequence pattern memory SF3.
  • the sequence control AST evaluates the received request signal as false information and omits a response signal. If the result is negative, the memory content of the key partial sequence pattern memory SF3 is transferred into the key partial sequence circular memory SF4 by switching the switch U2 into the switching position shown in FIG. 2, and the response signal is generated for the station wishing for synchronization.
  • This response signal essentially consists of the time of the master station and a code number, which is now encrypted with the time encryption specified by the station wishing for synchronization.
  • the changeover switch U3 is switched over to the switch position shown in an interrupted manner and, at the same time, the characteristic value signal is called up from the characteristic value generator KWG to which the sequence control AST is connected via lines which are designated a and b in FIG. 2.
  • the encryption takes place via the encryptor MD2, which can be, for example, a modulo-2 adder.
  • the encrypted signal Sig is then fed to the transmitter S and radiated from the antenna A via the transmission / reception switch W.
  • the station wishing to synchronize can now decrypt this response signal with the time encryption specified by itself and synchronize its station clock with the station clock of the master station. As a result, it is then able to generate the time-correct key and to establish any connection with one of the transceiver stations present in the synchronized radio network.
  • the method according to the invention can also be used in radio systems operating with preamble synchronization in conjunction with encryption.
  • the transceiver station wishing to establish a connection sends the called station a preamble P in plain text, which, like the signal frame SIG shown in FIG. 3, contains a time stamp ZM in addition to start information SI.
  • the start information SI determines the start phase of the pseudo random generator generating the key signal sequence within a period of its key signal sequence, while the time stamp ZM determines the time of the start of the pseudo random generator.
  • the preamble P is then followed by the useful information N, which is encrypted on the transmission side in the usual manner with the key signal sequence supplied by the pseudo-random generator and decrypted on the reception side.
  • the procedure is as will be explained in more detail with reference to FIG. 4.
  • the received signal frame SIG is supplied from the output of the receiver E on the one hand in the synchronization preamble receiver SE and on the other hand via the delay element LG and the switch s to the decryption device ES for the useful signal N.
  • the useful signal sink NS connects to the decryption device ES.
  • the runtime element LG gives the synchronizing preamble receiver SE the opportunity to first evaluate the preamble P, in order to then open the working contact of the switch s if any incorrect information is detected, and in this way to prevent further processing of the useful information.
  • the synchronization preamble receiver supplies the decryption device ES with the necessary control information for the start phase and the time of the pseudo-random generator within the decryption device ES and also transmits a portion of the preamble (process identifier) that is characteristic of the transmission process to the preamble pattern memory PM.
  • the control device ST uses the comparator V3 to compare the process identifier stored in the preamble pattern memory PM with corresponding process identifiers of previous correct transmissions stored in the preamble circulation memory PU.
  • the circulation function of the preamble circulation memory PU is initiated by switching the switch U4 into the switch position shown in broken lines.
  • the control device ST causes the process identifier to be transferred from the preamble pattern memory PM to the preamble circulation memory PU. If the comparator V3 has a positive result, the make contact of the switch s is opened and the received information interpreted as false information is suppressed.
  • the method can be used in radio systems working with encryption wherever an intelligent interferer can use recorded received radio messages to re-emit them in a later time range so that the receivers of the transceiver stations of the radio network to be disrupted can synchronize them with this re-emitted information. It is irrelevant whether it is one such, in particular tactical radio system is floor-floor systems, floor-air systems or air-air systems.

Landscapes

  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Engineering & Computer Science (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Road Signs Or Road Markings (AREA)
  • Aeration Devices For Treatment Of Activated Polluted Sludge (AREA)
  • Alarm Systems (AREA)
  • Developing Agents For Electrophotography (AREA)
  • Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)
  • Control And Other Processes For Unpacking Of Materials (AREA)
  • Transmitters (AREA)
  • Devices For Checking Fares Or Tickets At Control Points (AREA)
  • Synchronisation In Digital Transmission Systems (AREA)

Claims (4)

1. Procédé pour l'exécution d'une radiocommunication codée entre des postes émetteurs/récepteurs, notamment des postes émetteurs/récepteurs mobiles, et selon lequel au début d'au moins des opérations déterminées de transmission, une information de synchronisation et une information formant indicatif, qui sont fonction du temps, sont transmises entre deux postes, du côté réception, caractérisé par le fait
qu'une indication (indicatif d'opération) liée au code et marquant exclusivement l'opération de transmission considérée est dérivée de l'information d'indicatif reçue et est ensuite comparée immédiatement à des indicatifs d'opérations correctes précédentes de transmission de ce type, rapportés au même code et maintenus dans une mémoire circulante (SF4, PU), et qu'en outre, en fonction du résultat d'une telle comparaison, l'information contenue dans cette opération de transmission est rejetée comme étant une information fausse ou est évaluée en tant qu'information réelle.
2. Procédé pour l'exécution d'une radiocommunication codée à l'intérieur d'un réseau synchronisé de radiotélécommunications, constitué par des postes émetteurs/récepteurs, notamment des postes émetteurs/récepteurs mobiles, et selon lequel chaque opération de transmission commence, pour une information utile codée, par un plan non codé, selon la revendication 1, caractérisé par le fait que l'indicatif d'opération, tiré de chaque préambule reçu, est comparé respectivement aux indicatifs d'opérations conservés dans la mémoire circulante (PU), de toutes les opérations correctes précédentes de transmission,
qu'en outre une information fausse est identifiée dans le cas d'un résultat positif de la comparaison et qu'une information d'un résultat positif de la comparaison et qu'une information réelle est identifiée dans le cas d'un résultat négatif et qu'un indicatif d'opération prêt à être soumis à la comparaison n'est transféré dans la mémoire circulante que dans le cas d'un résultat négatif de la comparaison.
3. Procédé pour réaliser une première synchronisation d'un poste sur un réseau synchronisé de radiocommunications comportant une poste pilote, suivant la revendication 1, caractérisé par le fait
que le poste (poste appelant), qui désire réaliser une première synchronisation et utilise le même code, émet en clair, en direction du poste pilote, un signal de demande (Sig) qui inclut l'heure du poste, un indicatif de code ainsi qu'un modèle de séquence de code dérivé du code, de l'heure du poste et de l'indicatif de code, que le poste pilote produit, à partir des indications contenues dans le signal de demande reçu, un modèle de séquence de code correspondant, vérifie si ce dernier coïncide avec le modèle de séquence de code reçu et, dans le cas d'un résultat positif de cette première comparaison, libère le modèle de séquence de code reçu en tant qu'indicatif d'opération pour une seconde comparaison à des indicatifs d'opérations correspondants, déjà éventuellement présents dans la mémoire circulante (SF4), et les indications nécessaires pour la synchronisation du poste appelant sur le réseau sont retransmises en direction de ce poste par le poste pilote, conformément au codage temporel prédéterminé par le poste appelant.
4. Procédé suivant la revendication 3, caractérisé par le fait que seule une séquence partielle caractéristique du modèle de séquence de code reçu est utilisée comme indicatif d'opération pour la seconde comparaison.
EP86106999A 1985-06-04 1986-05-23 Procédé de réalisation d'une communication radiophonique chiffrée Expired - Lifetime EP0204226B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86106999T ATE55523T1 (de) 1985-06-04 1986-05-23 Verfahren zur durchfuehrung eines verschluesselten funkverkehrs.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3519902 1985-06-04
DE3519902 1985-06-04

Publications (3)

Publication Number Publication Date
EP0204226A2 EP0204226A2 (fr) 1986-12-10
EP0204226A3 EP0204226A3 (en) 1988-12-28
EP0204226B1 true EP0204226B1 (fr) 1990-08-08

Family

ID=6272342

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86106999A Expired - Lifetime EP0204226B1 (fr) 1985-06-04 1986-05-23 Procédé de réalisation d'une communication radiophonique chiffrée

Country Status (5)

Country Link
EP (1) EP0204226B1 (fr)
AT (1) ATE55523T1 (fr)
DE (1) DE3673241D1 (fr)
TR (1) TR23092A (fr)
ZA (1) ZA864121B (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4339464C2 (de) * 1993-11-19 1995-11-16 Litef Gmbh Verfahren zur Sprachverschleierung und -entschleierung bei der Sprachübertragung und Einrichtung zur Durchführung des Verfahrens

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2517073C1 (de) * 1975-04-18 1978-02-09 Siemens Ag Mit Gegenverkehr arbeitendes UEbertragungssystem
DE3518462A1 (de) * 1985-05-23 1986-11-27 Standard Elektrik Lorenz Ag, 7000 Stuttgart System zur verschluesselten nachrichtenuebertragung

Also Published As

Publication number Publication date
EP0204226A2 (fr) 1986-12-10
EP0204226A3 (en) 1988-12-28
ZA864121B (en) 1987-01-28
DE3673241D1 (de) 1990-09-13
TR23092A (tr) 1989-03-13
ATE55523T1 (de) 1990-08-15

Similar Documents

Publication Publication Date Title
DE69229346T2 (de) Dynamische verschlüsselungsschlüsselauswahl zur verschlüsselten funkübertragung
EP0283432B1 (fr) Procédé et dispositif de protection des éléments secrets dans un réseau d'appareils de chiffrage à administration ouverte des clés
EP1064810B1 (fr) Procede, station mobile et systeme de radiocommunication pour commander des fonctions liees a la securite lors de la gestion de communications
DE4423209C2 (de) Verfahren zum Durchführen einer Punkt-zu-Punkt-Kommunikation bei abhörsicheren Kommunikationssystemen
CH656761A5 (de) Datenuebertragungsanlage, die eine verschluesselungs/entschluesselungs-vorrichtung an jedem ende wenigstens einer datenverbindung aufweist.
DE3210081C2 (de) Verfahren und Anordnung zum Übertragen von verschlüsselten Texten
DE69634717T2 (de) Kryptographische Einrichtung zur Funkkomunikation
DE2556625B2 (de) Anordnung zur Identifizierung von Objekten mit auf eine Abfrageimpulsgruppe mit einem Impulskode antwortender Bake
EP1081000B1 (fr) Dispositif de sécurité
EP0204226B1 (fr) Procédé de réalisation d'une communication radiophonique chiffrée
EP0063332B1 (fr) Dispositif pour la transmission chiffrée d'informations numériques
EP0209079B1 (fr) Procédé de réalisation d'une communication radio chiffrée
EP1088401A1 (fr) Procede et dispositif a diversite en frequence porteuse destines a la transmission d'informations par un procede a sauts de frequence
DE4416705C1 (de) Elektronische Sicherungsvorrichtung und Verfahren zu dessen Betrieb
DE102005009490A1 (de) Verfahren, Vorrichtung, Gerät und System zum Schützen eines privaten Kommunikationsschlüssels für eine Fahrzeug-Umwelt-Kommunikation
EP1277632A2 (fr) Procédé de commande à distance pour le verrouillage et/ou le déverrouillage d'un véhicule
DE69814044T2 (de) Authentifizierungssystem, authentifizierungsvorrichtung, vorrichtung zur erzeugung von authentifizierungsdaten und authentifizierungsverfahren
DE3420874A1 (de) Verfahren und anordnung zur kontrolle des netzzugangs in fernmeldenetzen
DE2334330C3 (de) Schaltungsanordnung zum Übertragen von Nachrichtensignalen
DE3518462C2 (fr)
EP0187973A2 (fr) Procédé et circuit pour empêcher la réception non-autorisée de signaux de télévision hachés
DE10301100A1 (de) Telekommunikationsgestützter Zeitstempel
DE2060455C3 (de) Verfahren zur Kommandoübertragung an einen über Funk fernlenkbaren Flugkörper oder Satelliten und Kommandoübertragungssystem zur Durchführung dieses Verfahrens
DE2903419B3 (de) Funksystem
EP1052862B1 (fr) Procédé et appareil électronique de cryptage de numéros d'identification

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT CH DE FR GB IT LI NL SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT CH DE FR GB IT LI NL SE

17P Request for examination filed

Effective date: 19890627

17Q First examination report despatched

Effective date: 19891010

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT CH DE FR GB IT LI NL SE

REF Corresponds to:

Ref document number: 55523

Country of ref document: AT

Date of ref document: 19900815

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3673241

Country of ref document: DE

Date of ref document: 19900913

ET Fr: translation filed
ITF It: translation for a ep patent filed

Owner name: STUDIO JAUMANN

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19910523

Ref country code: AT

Effective date: 19910523

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19910524

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19910531

Ref country code: CH

Effective date: 19910531

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19911201

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19920131

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19930720

Year of fee payment: 8

EUG Se: european patent has lapsed

Ref document number: 86106999.5

Effective date: 19911209

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19950201

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050523