Cryptography – Communication system using cryptography – Data stream/substitution enciphering
Patent
1988-07-19
1989-10-24
Buczinski, Stephen C.
Cryptography
Communication system using cryptography
Data stream/substitution enciphering
380 20, 380 21, 380 43, 380 45, 380 50, H04L 902, H04N 7167
Patent
active
048767182
ABSTRACT:
A bit packet communication system includes a head-end having a software implemented 16 bit shaft register with a plurality of feed-forward taps and a different plurality of feed-back taps for simultaneously dividing and multiplying the input data bit packet to provide an output bit packet that is both encrypted and error protected. Dynamic encryption is provided by utilizing an initial preset for the software corresponding to a preset encryption key for the shift register. Authorized subscriber terminals are provided with memories and decryption keys are downloaded. The bit packets are assembled with a global bit packet encrypted with a global encryption key and subsequent individually addressed bit packets encrypted with address keys. The address keys and terminal addresses are permanently stored in the subscriber terminal memories. The global encryption keys are changed periodially. Means are provided in each subscriber terminal for storing a number of global decryption keys which are cycled through in attempts to decrypt the global packets. One of the global decryption keys is a permanent default key associated with the subscriber terminal to assure that communication with that terminal is possible despite a lack of knowledge of the terminal address or the other global decryption keys in its memory.
REFERENCES:
patent: 4159468 (1979-06-01), Barnes
patent: 4292650 (1981-09-01), Hendrickson
patent: 4323921 (1982-04-01), Guillou
patent: 4337483 (1982-06-01), Guillou
patent: 4354201 (1982-10-01), Sechet et al.
patent: 4434322 (1984-02-01), Ferrell
patent: 4531020 (1985-07-01), Wechselberger et al.
patent: 4531021 (1985-07-01), Bluestein et al.
patent: 4639548 (1987-01-01), Oshima et al.
patent: 4694491 (1987-09-01), Horne et al.
patent: 4815130 (1989-03-01), Lee et al.
Citta Richard W.
Gosc Paul M.
Mutzabaugh Dennis M.
Sgrignoli Gary J.
Buczinski Stephen C.
Zenith Electronics Corporation
LandOfFree
Secure data packet transmission system and method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Secure data packet transmission system and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Secure data packet transmission system and method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1593398