Cryptography – Key management – Having particular key generator
Patent
1984-01-03
1987-02-10
Cangialosi, Salvatore
Cryptography
Key management
Having particular key generator
380 49, H04L 900
Patent
active
046424245
ABSTRACT:
In a cryptographic communication system, a first encryptor transmits to a first decryptor and a second encryptor, co-located with the first decryptor, transmits to a second decryptor, which is co-located with the first encryptor. Each encryptor/decryptor pair is adapted to communicate using a selected non-self-synchronizing cryptographic mode. Whenever it is determined that synchronization between, say, the first encryptor and the first decryptor has been lost, both the first decryptor and the co-located, second encryptor are switched from the non-self-synchronizing mode to the self-synchronizing mode. This causes a loss of synchronization between the second encryptor and second decryptor since the latter is still operating in the non-self-synchronizing mode. Upon detection of this loss of synchronization, the second decryptor and the co-located, first encryptor are also switched from the non-self-synchronizing mode to the self-synchronizing mode. In due course, then, synchronization in both transmission directions automatically restores.
Return of each encryptor/decryptor pair to operation using the non-self-synchronizing mode is thereafter initiated by having each encryptor transmit a string of "1"s followed by a "0". The encryptor thereupon returns to the non-self-synchronizing mode. The string of "1"s is long enough to ensure that synchronization with the encryptor is re-established and when the "1"-to-"0" transition is detected at the decryptor, it, too, is switched back to the non-self-synchronizing mode.
REFERENCES:
patent: 3349175 (1967-10-01), Meisingset et al.
patent: 4079188 (1978-03-01), Kinch, Jr. et al.
patent: 4091423 (1978-05-01), Branscome
patent: 4109856 (1978-08-01), van Beverer et al.
patent: 4166922 (1979-09-01), Kinch, Jr. et al.
patent: 4169212 (1979-09-01), Kinch, Jr. et al.
patent: 4172963 (1979-10-01), Belcher et al.
patent: 4208544 (1980-06-01), Burke, Jr.
patent: 4211891 (1980-07-01), Glitz
patent: 4305152 (1981-12-01), Asakawa et al.
patent: 4313031 (1982-01-01), Widmer
patent: 4434322 (1984-02-01), Ferrell
patent: 4434323 (1984-02-01), Levine et al.
AT&T Information Systems Inc.
Cangialosi Salvatore
Lewis Aaron J.
Slusky Ronald D.
LandOfFree
Cryptographic transmission system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cryptographic transmission system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cryptographic transmission system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2363824