US4171513A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Secure communications system
Assignee: Lockheed Martin Corp
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Filing: 1969-07-22
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Granted: 1979-10-16
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Expires: 1989-07-22
Abstract
Abstract A privacy communication system is herein disclosed comprising apparatus for digitizing information to be transmitted, apparatus for logically adding a selected pseudo-random digital code to the digitized information, apparatus for removing the pseudo-random code upon reception and apparatus for synchronizing the transmitted and received pseudo-random codes.
Inventors
- 👤 Charles R. Otey
- 👤 Burton C. Winkler, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:35
CPC Classifications
H; H04; H04K; H04K1/00; H04K1/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
5 words
A privacy communications system, comprising:
Claim 2
Dependent Claim
5 words
A privacy communications system, comprising:
Claim 3
Dependent Claim
6 words
means for generating a digital signal;
Claim 4
Dependent Claim
6 words
means for generating a digital signal;
Claim 5
Dependent Claim
8 words
means for generating a pseudo-random digital code signal;
Claim 6
Dependent Claim
8 words
means for generating a pseudo-random digital code signal;
Claim 7
Dependent Claim
71 words
means for generating a clock signal, and a signal combining and separating circuit, including first and second exclusive OR gates, said first exclusive OR gate having inputs from the system clock means and from the output of said means for generating a pseudo-random digital code signal, said second exclusive OR gate having inputs from said first exclusive OR gate and from the output of said means for generating a digital signal.
Claim 8
Dependent Claim
71 words
means for generating a clock signal, and a signal combining and separating circuit, including first and second exclusive OR gates, said first exclusive OR gate having inputs from the system clock means and from the output of said means for generating a pseudo-random digital code signal, said second exclusive OR gate having inputs from said first exclusive OR gate and from the output of said means for generating a digital signal.
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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) | 1982-10-15 | 1983-04-16 | 1983-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-15 | 1987-04-16 | 1987-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-15 | 1991-04-16 | 1991-10-16 | $7700.00 | Window Closed / Lapsed |