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US5054067A Expired / Lapsed US ⏱️ 0.0 years remaining

Block-cipher cryptographic device based upon a pseudorandom nonlinear sequence generator

Assignee: Arris Technology Inc
•
Filing: 1990-02-21
•
Granted: 1991-10-01
•
Expires: 2010-02-21
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Abstract

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. <IMAGE> <IMAGE>

Inventors

  • 👤 Paul Moroney
  • 👤 Christopher J. Bennett

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 10:55
CPC Classifications
H; H04; H04L; H04L9/00; H04L9/06; H04L9/065; H04L9/0656; H04L9/0662; H04L9/0668; H04L9/0618; H04L9/0625; H04L2209/00; H04L2209/12

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 142 words
A block-cipher cryptographic device for processing plain-text or encrypted input data with a key signal to provide encrypted or decrypted output data respectively, comprising a shift register for receiving the input data; and data processing means, including a pseudorandom nonlinear sequence generator, for executing a data processing routine for a selected number of cycles to provide the output data, wherein the data processing routine includes: processing the contents of said shift register with a key signal to provide initially processed data; initializing the pseudorandom nonlinear sequence generator with the initially processed data; running the pseudorandom nonlinear sequence generator to generate a keystream; segregating portions of the keystream; processing 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.
Claim 2
Dependent Claim 142 words
A block-cipher cryptographic device for processing plain-text or encrypted input data with a key signal to provide encrypted or decrypted output data respectively, comprising a shift register for receiving the input data; and data processing means, including a pseudorandom nonlinear sequence generator, for executing a data processing routine for a selected number of cycles to provide the output data, wherein the data processing routine includes: processing the contents of said shift register with a key signal to provide initially processed data; initializing the pseudorandom nonlinear sequence generator with the initially processed data; running the pseudorandom nonlinear sequence generator to generate a keystream; segregating portions of the keystream; processing 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.
Claim 3
Dependent Claim 38 words
A device according to claim 1, wherein the data processing means provide said output data in the shift register by said shifting of said blocks of processed data into the shift register for said selected number of cycles.
Claim 4
Dependent Claim 54 words
A device according to claim 1, wherein the data processing routine includes segregating a portion of said keystream in accordance with a routine that begins said segregated portion at a time indicated by a duration indication that is separately provided for each of the cycles and may be different for each of the cycles.
Claim 5
Dependent Claim 67 words
A device according to claim 3, wherein the routine for segregating said portion of said keystream includes providing said segregated portion by segregating 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 that is separately provided for each of the cycles and may be different for each of the cycles.
Claim 6
Dependent Claim 63 words
A device according to claim 4, wherein the data processing means includes means for providing said initially processed data by first processing said shift register contents and said key signal and then rotating data produced by said first processing in response to a rotation indication that is separately provided for each of the cycles and may be different for each of the cycles.
Claim 7
Dependent Claim 20 words
A device according to claim 5, wherein the data processing means includes a dynamic-feedback-arrangement-scrambling-technique keystream generator for generating said keystream.
Claim 8
Dependent Claim 20 words
A device according to claim 4, wherein the data processing means includes a dynamic-feedback-arrangement-scrambling-technique keystream generator for generating said keystream.
Claim 9
Dependent Claim 63 words
A device according to claim 3, wherein the data processing means includes means for providing said initially processed data by first processing said shift register contents and said key signal and then rotating data produced by said first processing in response to a rotation indication that is separately provided for each of the cycles and may be different for each of the cycles.
Claim 10
Dependent Claim 20 words
A device according to claim 8, wherein the data processing means includes a dynamic-feedback-arrangement-scrambling-technique keystream generator for generating said keystream.
Claim 11
Dependent Claim 20 words
A device according to claim 3, wherein the data processing means includes a dynamic-feedback-arrangement-scrambling-technique keystream generator for generating said keystream.
Claim 12
Dependent Claim 64 words
A device according to claim 1, wherein the data processing routine includes segregating a portion of said keystream by segregating every nth bit of the keystream from a beginning of said segregated portion for a selected number of segregated bits in response to a frequency indication that is separately provided for each of the cycles and may be different for each of the cycles.
Claim 13
Dependent Claim 63 words
A device according to claim 11, wherein the data processing means includes means for providing said initially processed data by first processing said shift register contents and said key signal and then rotating data produced by said first processing in response to a rotation indication that is separately provided for each of the cycles and may be different for each of the cycles.
Claim 14
Dependent Claim 20 words
A device according to claim 12, wherein the data processing means includes a dynamic-feedback-arrangement-scrambling-technique keystream generator for generating said keystream.
Claim 15
Dependent Claim 20 words
A device according to claim 11, wherein the data processing means includes a dynamic-feedback-arrangement-scrambling-technique keystream generator for generating said keystream.
Claim 16
Dependent Claim 63 words
A device according to claim 1, wherein the data processing means includes means for providing said initially processed data by first processing said shift register contents and said key signal and then rotating data produced by said first processing in response to a rotation indication that is separately provided for each of the cycles and may be different for each of the cycles.
Claim 17
Dependent Claim 20 words
A device according to claim 15, wherein the data processing means includes a dynamic-feedback-arrangement-scrambling-technique keystream generator for generating said keystream.
Claim 18
Dependent Claim 20 words
A device according to claim 1, wherein the data processing means includes a dynamic-feedback-arrangement-scrambling-technique keystream generator for generating said keystream.

References Cited (Backward Citations)

US4255811A Cited
US4316055A Cited
US4663500A Cited
US4890324A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-09-30 1995-04-01 1995-10-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-09-30 1999-04-01 1999-10-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-09-30 2003-04-01 2003-10-01 $7700.00 Window Closed / Lapsed

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