Cryptography – Particular algorithmic function encoding – Nbs/des algorithm
Patent
1993-12-02
1995-10-03
Cain, David C.
Cryptography
Particular algorithmic function encoding
Nbs/des algorithm
380 23, 380 49, 380 46, H04L 900
Patent
active
054558620
ABSTRACT:
An encryption/decryption unit (EDU) and method for determining a data encryption key used in encrypting and decrypting data transmitted over a non-secure communication link. Each EDU includes a central processing unit (CPU) that controls its operation, random access memory (RAM) in which one or more sets of seed keys are stored, and a data encryption standard (DES) coprocessor that implements a data encryption algorithm developed by the U.S. National Bureau of Standards. The CPU includes special circuitry enabling it to operate in an encrypted mode so that it cannot be interrogated to discover the program or data stored therein. Each EDU randomly generates a pointer, bytes of which determine the number of times that a loop is repeated in which values (initially determined by two of the seed keys) are XORed together and encrypted using one of the seed keys to determine a portion of the data encryption key (DEK). The pointer is encrypted, along with other information, producing an encrypted key header that is transmitted to the other EDU establishing the link. Upon receiving the encrypted key header, it is decrypted, and the decrypted pointer is used by the receiving EDU to determine the portion of the DEK developed by the other EDU. The two portions of the DEK are then logically combined at each EDU to produce the final DEK, which is then used during the current communication session for encrypting data exchange between the two EDUs.
REFERENCES:
patent: Re33189 (1990-03-01), Lee et al.
patent: 4218582 (1980-08-01), Hellman et al.
patent: 4578531 (1986-03-01), Everhart et al.
patent: 4607137 (1986-08-01), Jansen et al.
patent: 4677670 (1987-06-01), Henderson, Jr.
patent: 4771429 (1988-09-01), Davis et al.
patent: 4771462 (1988-09-01), Hannan et al.
patent: 4809327 (1989-02-01), Shima
patent: 4876716 (1989-10-01), Okamoto
patent: 4888802 (1989-12-01), Cooney
patent: 4910776 (1990-03-01), Dyke
patent: 4985919 (1991-01-01), Naruse et al.
patent: 5001750 (1991-03-01), Kato et al.
patent: 5003597 (1991-03-01), Merkle
patent: 5029208 (1991-07-01), Tanaka
patent: 5073935 (1991-12-01), Pastor
patent: 5081678 (1992-01-01), Kaufman et al.
patent: 5124117 (1992-06-01), Tatebayashi et al.
patent: 5144665 (1992-09-01), Takaragi et al.
patent: 5146498 (1992-09-01), Smith
patent: 5204901 (1993-04-01), Hershey et al.
patent: 5222136 (1993-06-01), Rasmussen et al.
patent: 5222141 (1993-06-01), Killian
patent: 5237611 (1993-08-01), Rasmussen et al.
B. Schneier, "Untangling Public-Key Cryptography," Dr. Dobb's Journal, May 1992, 8 pages.
A. Konheim, Cryptography: A Primer, John Wiley and Sons, Inc., 1981, pp. 288-293 and 331-347.
Cain David C.
Crest Industries, Inc.
LandOfFree
Apparatus and method for encrypting communications without excha does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus and method for encrypting communications without excha, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus and method for encrypting communications without excha will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1082278