Cryptography – Key management – Having particular key generator
Patent
1995-04-03
1997-04-08
Cain, David C.
Cryptography
Key management
Having particular key generator
380 49, 380 28, 380 21, H04L 900
Patent
active
056195761
ABSTRACT:
Binary data is encrypted or decrypted using a final key. The final key is formed by manipulating one or more user keys, a base key and a block of data, and combining the manipulated keys and data using an exclusive-OR operation. The data to be encrypted or decrypted are combined with the final key using a circular exclusive-OR operation. A new final key is formed for each block of data. The user and base keys are binary sequences having any number of bits. The user key may be input to the present invention directly in binary form or in any other suitable form that the present invention can interpret as a binary sequence, such as a string of ASCII-encoded alphanumeric characters. Manipulating the user key includes the steps of shuffling or permuting segments of the user key, such as bytes, circularly shifting the permuted user key by a number of bit positions, and filling a location with one or more copies of the permuted and shifted key such that the result has a length equal to that of the base key. The ordering of the segments of the user key in the permutation step and the number of bit positions by which the user key is shifted in the shifting step are determined in response to the value and position of the segments of the user key itself. Manipulating the base key includes the step of circularly shifting the base key by a number of bit positions that is determined in response to the value and position of segments of the user key.
REFERENCES:
patent: 4200770 (1980-04-01), Hellman et al.
patent: 4225935 (1980-09-01), Zscheile, Jr. et al.
patent: 4369332 (1983-01-01), Campbell, Jr.
patent: 4503287 (1985-03-01), Morris et al.
patent: 4596898 (1986-06-01), Pemmaraju
patent: 4663500 (1987-05-01), Okamoto et al.
patent: 4819267 (1989-04-01), Cargile et al.
patent: 4897876 (1990-01-01), Davies
patent: 5115467 (1992-05-01), Esserman et al.
patent: 5231662 (1993-07-01), Van Rumpt et al.
patent: 5237612 (1993-08-01), Raith
patent: 5241599 (1993-08-01), Bellovin et al.
LandOfFree
Variable-key cryptography 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 Variable-key cryptography system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variable-key cryptography system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2402076