Cryptography – Communication system using cryptography – Symmetric key cryptography
Reexamination Certificate
2002-03-26
2010-12-28
Smithers, Matthew B (Department: 2437)
Cryptography
Communication system using cryptography
Symmetric key cryptography
C380S043000
Reexamination Certificate
active
07860251
ABSTRACT:
An encryption-decryption circuit for encrypting and decrypting data. The encryption-decryption circuit comprises: 1) an N-bit shift register for storing and shifting an N bit keyword; 2) a first exclusive-OR gate array for receiving M bits from the N-bit shift register and generating a one-bit exclusive-OR result that is shifted into an input of the N-bit shift register; and 3) a second exclusive-OR gate array comprising K exclusive-OR gates, each of the K exclusive-OR gates receiving one of K bits from the N-bit shift register and one of K data bits from a received K-bit data word and generating therefrom an exclusive-OR result. The K exclusive-OR gates thereby produce one of: i) a K-bit encrypted data word and ii) a K-bit unencrypted data word.
REFERENCES:
patent: 3657699 (1972-04-01), Rocher et al.
patent: 3899951 (1975-08-01), Griffith et al.
patent: 4228712 (1980-10-01), Uchiyama et al.
patent: 4304962 (1981-12-01), Fracassi et al.
patent: 4965881 (1990-10-01), Dilley
patent: 5365588 (1994-11-01), Bianco et al.
patent: 5377270 (1994-12-01), Koopman et al.
patent: 5910907 (1999-06-01), Chen et al.
patent: 6763363 (2004-07-01), Driscoll
patent: 7035290 (2006-04-01), Lyle
patent: 7068788 (2006-06-01), Haque et al.
patent: 7558326 (2009-07-01), Lyle et al.
Alfred J. Menezes, Paul C. Van Oorschot, Scott A. Vanstone. Handbook of Applied Cryptography. 1997. CRC Press LLC. pp. 191-222.
Bruce Schneier. Applied Cryptography: Protocols, Algorithms, and Source Code in C. 1996. John Wiley & Sons, Inc. pp. 372-395.
Apparatus for Low to Medium Secure Encoding of Data. IBM Technical Disclosure Bulletin. vol. 23. Issue 7A. Dec. 1980. pp. 2966-2967.
Schneier, Bruce. Applied Cryptography. 1996. John Wiley & Sons. Inc. Second Edition. pp. 4, 15-17, 173, 181, 372-379, 382-385.
National Semiconductor Corporation
Smithers Matthew B
Teslovich Tamara
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