US4845749A
Expired / Lapsed
US
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Secure teleconferencing system
Assignee: Iconectiv LLC
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Filing: 1987-12-21
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Granted: 1989-07-04
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Expires: 2007-12-21
Abstract
Abstract A secure audio teleconferencing system is disclosed. The secure teleconferencing system comprises a centralized facility or bridge to which a plurality of participants is connected. The role of the bridge is to receive encrypted message signals from the participants and to add the encrypted message signals, modulo some known number. The result is then transmitted to the participants. Each participant is able to decrypt the modular sum of encrypted message signals, to obtain the desired ordinary sum of clear text message signals. In accordance with the invention, the message signals remain encrypted throughtout processing by the bridge. There are no non-encrypted messages.
Inventors
- 👤 Ernest F. Brickell
- 👤 Pil J. Lee
- 👤 Yacov Yacobi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:29
CPC Classifications
H; H04; H04K; H04K1/00
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
93 words
A method for enabling the secure exchange of messages in a multi-party communications system comprising generating message signals at a plurality of participant terminals, encrypting said message signals at each of said terminals by utilizing at least one modular arithmetic operation to combine each of the message signals with at least one pseudo-random number, transmitting said encrypted message signals to a bridge, and processing said encrypted message signals at said bridge without decryption by combining encrypted message signals from at least some of said participant terminals to form a resultant encrypted message signal.
Claim 2
Independent Claim
93 words
A method for enabling the secure exchange of messages in a multi-party communications system comprising generating message signals at a plurality of participant terminals, encrypting said message signals at each of said terminals by utilizing at least one modular arithmetic operation to combine each of the message signals with at least one pseudo-random number, transmitting said encrypted message signals to a bridge, and processing said encrypted message signals at said bridge without decryption by combining encrypted message signals from at least some of said participant terminals to form a resultant encrypted message signal.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein said resultant encrypted message signal is broadcast from said bridge to said terminals.
Claim 4
Dependent Claim
13 words
The method of claim 1 wherein said message signals are digitized audio signals.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein said modular arithmetic operation is modular addition.
Claim 6
Dependent Claim
13 words
The method of claim 1 wherein said modular arithmetic operation is modular multiplication.
Claim 7
Dependent Claim
26 words
The method of claim 1 wherein each of said message signals is encrypted utilizing first and second modular arithmetic operations involving first and second pseudo-random numbers.
Claim 8
Dependent Claim
35 words
The method of claim 1 wherein said step of processing said encrypted signals at said bridge comprises the step of summing said encrypted message signals from at least some of said participant terminals without decryption.
Claim 9
Dependent Claim
38 words
The method of claim 7 wherein said sum of encrypted message signals is broadcast to said terminals, and at said terminals, said sum of encrypted message signals is decrypted to produce a sum of clear text message signals.
Claim 10
Dependent Claim
101 words
A secure teleconferencing system comprising: a plurality of participant terminals and a bridge, each of said participant terminals comprising means for generating a message signal, means for generating a pseudo-random number, and means for encrypting the message signal by combining the message signal with the pseudo-random number utilizing a modular arithmetic operation, and said bridge comprising means for receiving encrypted message signals from said participant terminals, means for processing the encrypted message signals from at least some of said participant terminals without decryption to form a resultant encrypted signal, and means for broadcasting said resultant encrypted signal to said participant terminals.
Claim 11
Dependent Claim
101 words
A secure teleconferencing system comprising: a plurality of participant terminals and a bridge, each of said participant terminals comprising means for generating a message signal, means for generating a pseudo-random number, and means for encrypting the message signal by combining the message signal with the pseudo-random number utilizing a modular arithmetic operation, and said bridge comprising means for receiving encrypted message signals from said participant terminals, means for processing the encrypted message signals from at least some of said participant terminals without decryption to form a resultant encrypted signal, and means for broadcasting said resultant encrypted signal to said participant terminals.
Claim 12
Dependent Claim
24 words
The system of claim 9 wherein each of said participant terminals further includes means for decrypting the resultant encrypted signal received from said bridge.
Claim 13
Dependent Claim
30 words
The system of claim 9 wherein said processing means comprises means for summing the encrypted message signals from at least some of said participant terminals by means of modular addition.
Claim 14
Dependent Claim
13 words
The system of claim 9 wherein said message signals are digitized audio signals.
Claim 15
Dependent Claim
20 words
The system of claim 9 wherein said pseudo-random number generating means in each of said terminals has a key input.
Claim 16
Dependent Claim
21 words
The system of claim 13 wherein the pseudo-random number generating means in each of said terminals has a distinct key input.
Claim 17
Dependent Claim
21 words
The system of claim 13 wherein the pseudo-random number generating means in each of said terminals has a common key input.
Claim 18
Dependent Claim
20 words
The system of claim 9 wherein said pseudo-random number generating means in each of said terminals has a sync input.
Claim 19
Dependent Claim
21 words
The system of claim 16 wherein the pseudo-random number generating means in each of said terminals has a common sync input.
Claim 20
Dependent Claim
21 words
The system of claim 16 wherein the pseudo-random number generating means in each of said terminals has a distinct sync input.
Claim 21
Dependent Claim
79 words
A terminal for use in a secure multi-party telecommunications system including a plurality of terminals and a bridge, said terminal comprising: means for generating a message signal, means for generating a pseudo-random number, means for encrypting said message signal using a modular arithmetic operation to combine said message signal with said pseudo-random number, means for transmitting said encrypted message to said bridge, and means for decrypting a signal received from said bridge comprising a plurality of encrypted message signals.
Claim 22
Dependent Claim
79 words
A terminal for use in a secure multi-party telecommunications system including a plurality of terminals and a bridge, said terminal comprising: means for generating a message signal, means for generating a pseudo-random number, means for encrypting said message signal using a modular arithmetic operation to combine said message signal with said pseudo-random number, means for transmitting said encrypted message to said bridge, and means for decrypting a signal received from said bridge comprising a plurality of encrypted message signals.
Claim 23
Dependent Claim
21 words
The terminal of claim 19 wherein said pseudo-random generating means uses the data encryption standard function to generate said pseudo-random number.
Claim 24
Dependent Claim
106 words
A terminal for use in a secure audio teleconferencing system including a plurality of terminals and a bridge, said terminal comprising microphone means for generating an analog audio message signal, linear encoding means for digitizing said message signal, generator means for generating a pseudo-random number in response to a key input and a sync word input, means for encrypting said digitized message signal by using a modular arithmetic operation to combine said digitized message signal and said pseudo-random number, means for transmitting said encrypted message signal to said bridge, and means for decrypting a signal received from said bridge comprising a plurality of encrypted message signals.
Claim 25
Dependent Claim
106 words
A terminal for use in a secure audio teleconferencing system including a plurality of terminals and a bridge, said terminal comprising microphone means for generating an analog audio message signal, linear encoding means for digitizing said message signal, generator means for generating a pseudo-random number in response to a key input and a sync word input, means for encrypting said digitized message signal by using a modular arithmetic operation to combine said digitized message signal and said pseudo-random number, means for transmitting said encrypted message signal to said bridge, and means for decrypting a signal received from said bridge comprising a plurality of encrypted message signals.
Claim 26
Dependent Claim
76 words
A bridge for use in a secure multi-party telecommunications system comprising a plurality of participant terminals and said bridge, said bridge comprising: means for receiving encrypted message signals from said participant terminals, means for utilizing modular addition to combine the encrypted message signals from at least some of said participant terminals without decrypting said message signals to form a total encrypted message signals, and means for broadcasting said total encrypted message signal to said participant terminals.
Claim 27
Dependent Claim
76 words
A bridge for use in a secure multi-party telecommunications system comprising a plurality of participant terminals and said bridge, said bridge comprising: means for receiving encrypted message signals from said participant terminals, means for utilizing modular addition to combine the encrypted message signals from at least some of said participant terminals without decrypting said message signals to form a total encrypted message signals, and means for broadcasting said total encrypted message signal to said participant terminals.
Claim 28
Independent Claim
79 words
A method for enabling the exchange of message signals in a multi-party communications system comprising the steps of encrypting said message signals by utilizing at least one modular arithmetic operation to combine each of said message signals with at least one pseudo-random number, combining at least some of said encrypted messages without decryption to form a resultant encrypted message signal and decrypting said resultant encrypted message signal to form a signal comprising a plurality of clear text message signals.
Claim 29
Independent Claim
79 words
A method for enabling the exchange of message signals in a multi-party communications system comprising the steps of encrypting said message signals by utilizing at least one modular arithmetic operation to combine each of said message signals with at least one pseudo-random number, combining at least some of said encrypted messages without decryption to form a resultant encrypted message signal and decrypting said resultant encrypted message signal to form a signal comprising a plurality of clear text message signals.
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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) | 1992-07-03 | 1993-01-02 | 1993-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-03 | 1997-01-02 | 1997-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-03 | 2001-01-02 | 2001-07-04 | $7700.00 | Window Closed / Lapsed |