US3936601A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for altering the synchronous compare character in a digital data communication system
Assignee: Unisys Corp
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Filing: 1974-05-28
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Granted: 1976-02-03
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Expires: 1994-05-28
Abstract
Abstract In order to provide for a digital data transmitting system of increased security, means are provided to dynamically alter the synchronous compare character between message transmissions. Included in the data communication system are: a character general for programmatically generating a synchronous compare character; a character storage register for storing the character so generated; and circuitry for moving the synchronous character from the storage register to the data transmission circuitry. By dynamically altering the synchronous character between message transmissions, it is possible to substantially enhance the security of the data transmission system.
Inventors
- 👤 Carl Obeginski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:06
CPC Classifications
H; H04; H04K; H04K1/00; H04L; H04L7/00; H04L7/0079; H04L7/0083; H04L7/04; H04L7/041; H04L9/00; H04L9/06; H04L9/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
97 words
In an apparatus for transmitting digital data in a synchronous mode, the improvement comprising: character generating means for generating a plurality of different synchronizing characters in a preselected nonrepetitious pattern thereby dynamically altering said synchronizing characters; storage means for storing at least one of said synchronizing characters; transmitting means for transmitting digital data and at least one of said synchronizing characters; means for transferring at least one of said synchronizing characters from said storage means to said transmitting means; and said dynamically alterable synchronizing characters preventing unauthorized interception of the digital data transmitted by the transmitting means.
Claim 2
Dependent Claim
97 words
In an apparatus for transmitting digital data in a synchronous mode, the improvement comprising: character generating means for generating a plurality of different synchronizing characters in a preselected nonrepetitious pattern thereby dynamically altering said synchronizing characters; storage means for storing at least one of said synchronizing characters; transmitting means for transmitting digital data and at least one of said synchronizing characters; means for transferring at least one of said synchronizing characters from said storage means to said transmitting means; and said dynamically alterable synchronizing characters preventing unauthorized interception of the digital data transmitted by the transmitting means.
Claim 3
Independent Claim
68 words
A method for transmitting digital data to a receiving apparatus in a synchronous mode comprising the steps of: generating a first synchronous character; transmitting said first synchronous character to the receiving apparatus; transmitting a first message in digital form to the receiving apparatus; and generating different synchronous characters in a preselected nonrepetitious pattern to provide dynamically altered characters to precede future message transmissions thereby preventing unauthorized interception thereof.
Claim 4
Independent Claim
68 words
A method for transmitting digital data to a receiving apparatus in a synchronous mode comprising the steps of: generating a first synchronous character; transmitting said first synchronous character to the receiving apparatus; transmitting a first message in digital form to the receiving apparatus; and generating different synchronous characters in a preselected nonrepetitious pattern to provide dynamically altered characters to precede future message transmissions thereby preventing unauthorized interception thereof.
Claim 5
Dependent Claim
19 words
The method of claim 2 wherein a predetermined number of said synchronous characters are transmitted before transmitting said messages.
Claim 6
Dependent Claim
33 words
The method of claim 2 including the step of transmitting a predetermined number of messages after said step of transmitting said first message before generating subsequent synchronous characters to precede future message transmissions.
Claim 7
Dependent Claim
19 words
The method of claim 4 wherein a predetermined number of said synchronous characters are transmitted before transmitting said message.
Claim 8
Dependent Claim
34 words
The method of claim 5 including the additional step of including in each of said messages transmitted sufficient information to the receiving apparatus to enable the receiving apparatus to generate the next synchronous character.
References Cited (Backward Citations)
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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) | 1979-02-02 | 1979-08-04 | 1980-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-02 | 1983-08-04 | 1984-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-02 | 1987-08-04 | 1988-02-03 | $7700.00 | Window Closed / Lapsed |