US3911216A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nonlinear code generator and decoder for transmitting data securely
Assignee: Bull HN Information Systems Italia SpA
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Filing: 1973-12-17
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Granted: 1975-10-07
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Expires: 1993-12-17
Abstract
Abstract A code generator for encoding digital data includes a first feedback shift register for code generation and at least a second feedback shift register interconnected with the first shift register whereby the generated code is effectively nonlinear. Clear text may be applied as an input to the first shift register or the generated code may be applied to the clear text outside of the first shift register. Similar decoding apparatus is employed to recover the clear text from the transmitted cryptogram.
Inventors
- 👤 Douglas J Bartek
- 👤 Thomas H Howell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:54
CPC Classifications
H; H04; H04L; H04L9/00; H04L9/06; H04L9/065; H04L9/0656; H04L9/0662; H04L9/0668
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
143 words
Code apparatus for use in the transmission of digital data in coded form comprising a first shift register having a plurality of serially connected bistable stages, at least one feedback loop interconnecting the output of one stage and the input of a preceding stage of said first shift register; a second shift register having a plurality of serially connected bistable stages, said second shift register interconnected in said feedback loop of said first shift register whereby cycling of said first and second shift registers is interdependent; at least one feedback loop interconnecting the output of one stage and the input of a preceding stage of said second shift register; and logic means interconnecting the output of one stage of said second shift register to said first shift register whereby said first and second shift registers cooperatively function to produce an effectively nonlinear code.
Claim 2
Dependent Claim
143 words
Code apparatus for use in the transmission of digital data in coded form comprising a first shift register having a plurality of serially connected bistable stages, at least one feedback loop interconnecting the output of one stage and the input of a preceding stage of said first shift register; a second shift register having a plurality of serially connected bistable stages, said second shift register interconnected in said feedback loop of said first shift register whereby cycling of said first and second shift registers is interdependent; at least one feedback loop interconnecting the output of one stage and the input of a preceding stage of said second shift register; and logic means interconnecting the output of one stage of said second shift register to said first shift register whereby said first and second shift registers cooperatively function to produce an effectively nonlinear code.
Claim 3
Dependent Claim
66 words
Code apparatus as defined by claim 1 wherein said apparatus includes a third shift register having a plurality of serially connected bistable stages and at least one feedback loop interconnecting the output of one stage and the input of a preceding stage, and means interconnecting the output of one stage of said third shift register to a shift register stage outside of said third shift register.
Claim 4
Dependent Claim
35 words
Code apparatus as defined by claim 2 wherein said means interconnecting the output of one stage of said third shift register includes adder means at the input of one stage of said first shift register.
Claim 5
Dependent Claim
21 words
Code apparatus as defined by claim 2 wherein said third shift register cycles independently from said first and second shift registers.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-06 | 1979-04-07 | 1979-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-06 | 1983-04-07 | 1983-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-06 | 1987-04-07 | 1987-10-07 | $7700.00 | Window Closed / Lapsed |