US5199069A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic encryption selector
Assignee: Motorola Solutions Inc
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Filing: 1991-02-25
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Granted: 1993-03-30
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Expires: 2011-02-25
Abstract
Abstract A radio (100) capable of automatically selecting an encryption algorithm from among a plurality of algorithms (122 and 124) is disclosed. The method for automatically selecting the proper encryption hybrid includes the steps of: attempting to decrypt the encrypted signal with one of the plurality of encryption algorithms; determining if the encryption algorithm used to decrypt the encrypted signal matches the encryption algorithm used by the encrypted signal; and developing a control signal upon the proper matching of the encryption algorithms.
Inventors
- 👤 Steven T. Barrett
- 👤 Bruce D. Oberlies
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:10
CPC Classifications
H; H04; H04K; H04K1/00; H04L; H04L9/00; H04L9/12; H04L9/14; H04L9/16; H04L2209/00; H04L2209/80
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
130 words
A radio capable of automatically selecting a proper algorithm from among a plurality of different algorithms, each having an associated key, for decrypting an encrypted signal which is received by the radio and one of the plurality of algorithms in the radio is designated to be a default algorithm, the radio comprising: a. means for automatically decrypting the received encrypted signal with one of the plurality of different algorithms; b. means for determining if the algorithm chosen to decrypt the encrypted signal has properly decrypted the encrypted signal and selecting another algorithm from among the plurality of algorithims if the encrypted signal has not been properly decrypted: and c. means for developing a control signal upon the proper decryption of the received encrypted signal in order to indicate correct decryption.
Claim 2
Dependent Claim
130 words
A radio capable of automatically selecting a proper algorithm from among a plurality of different algorithms, each having an associated key, for decrypting an encrypted signal which is received by the radio and one of the plurality of algorithms in the radio is designated to be a default algorithm, the radio comprising: a. means for automatically decrypting the received encrypted signal with one of the plurality of different algorithms; b. means for determining if the algorithm chosen to decrypt the encrypted signal has properly decrypted the encrypted signal and selecting another algorithm from among the plurality of algorithims if the encrypted signal has not been properly decrypted: and c. means for developing a control signal upon the proper decryption of the received encrypted signal in order to indicate correct decryption.
Claim 3
Dependent Claim
32 words
A radio as defined in claim 1, wherein the control signal is a signal which is produced by an encryption hybrid which stores the algorithm used to properly decrypt the encrypted signal.
Claim 4
Dependent Claim
31 words
A radio as defined in claim 1, further comprising d. means for setting a transmit hangtime timer upon a control signal being developed and the default algorithm not being presently selected.
Claim 5
Dependent Claim
42 words
A radio as defined in claim 1, further comprising: d. means for setting a receive hangtime delay timer once a control signal is developed if the algorithm which is being used to decrypt the encrypted signal is not the default encryption algorithm.
Claim 6
Dependent Claim
54 words
A radio as defined in claim 1, further comprising: d. means responsive to the means for developing a control signal, for transmitting an encrypted message using the algorithm that was used to properly decrypt the received encrypted message even when the algorithm used to decrypt the received encrypted signal is not the default algorithm.
Claim 7
Dependent Claim
43 words
A radio as defined in claim 5, further comprising: d. means responsive to the means for developing a control signal, for reverting to the default algorithm after a predetermined period of time has passed since the received encrypted signal has been properly decrypted.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-03-29 | 1996-09-28 | 1997-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-03-29 | 2000-09-28 | 2001-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-03-29 | 2004-09-28 | 2005-03-30 | $7700.00 | Window Closed / Lapsed |