Title:
疑似ランダム非線形シーケンス発生装置に基づいたブロック暗号装置
Document Type and Number:
Japanese Patent JP3566311
Kind Code:
B2
Abstract:
A block-cipher cryptographic device that processes plaintext/encrypted input data with a key signal to provide encrypted/decrypted output data. Such device includes a shift register (10) for receiving input data (13); and data processing means (12), including a pseudorandom nonlinear sequence generator (32), for executing the following data processing routine a selected number of cycles to provide output data (15): processing (18, 22, 30) the contents (16) of said shift register with a key signal (14) to provide initially processed data (28); initializing the pseudorandom nonlinear sequence generator with the initially processed data; running the pseudorandom nonlinear sequence generator to generate a keystream (34); segregating (36, 38) portions of the keystream; processing (44) said segregated portions of said keystream with a portion of the data in the shift register to provide a block of processed data; and shifting said block of processed data into the shift register. To further increase the randomness of the pseudorandom keystream generator, and hence the encryption security, the data processing routine segregates the keystream in accordance with a routine (36) wherein the beginning of said segregated portion is provided at a time related to the beginning of the keystream in response to a duration indication (Y); segregates (38) every nth bit of the keystream from said beginning of said segregated portion for a selected number of segregated bits in response to a frequency indication (n); and provides said initially processed data by first processing (18) said shift register contents and said key signal and then rotating (22) data produced by said first processing in response to a rotation indication (X). The duration indication, the frequency indication and the rotation indication are each separately provided for each of the cycles and may be different for each of the cycles.
Inventors:
Paul Moloney
Christopher John Bennett
Daniel Ray Kindred
Christopher John Bennett
Daniel Ray Kindred
Application Number:
JP2638591A
Publication Date:
September 15, 2004
Filing Date:
February 20, 1991
Export Citation:
Assignee:
GENERAL INSTRUMENT CORPORATION
International Classes:
H04L9/00; G09C1/00; H04L9/06; H04L9/08; H04L9/26; (IPC1-7): G09C1/00
Domestic Patent References:
| JP222693A | ||||
| JP64500227A |
Attorney, Agent or Firm:
Takehiko Suzue
Sadao Muramatsu
Ryo Hashimoto
Toshio Shirane
Sadao Muramatsu
Ryo Hashimoto
Toshio Shirane