US5146497A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Group rekey in a communication system
Assignee: Motorola Solutions Inc
•
Filing: 1991-02-27
•
Granted: 1992-09-08
•
Expires: 2011-02-27
Abstract
Abstract This method of key distribution rekeys (605) a group of communication units (107) within an encrypted communication system with over-the-channel rekeying. The method uses a key management controller (101) to manage and distribute keys (1541) to a plurality of communication units and handle acknowledgments from the plurality of communication units that are delayed from receipt of the rekeying message. The rekeying message (615) is sent to any of the group of communication units (107) when an acknowledgment is not received (611) from one or more of the group of communication units (107).
Inventors
- 👤 Michael W. Bright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:05
CPC Classifications
H; H04; H04L; H04L9/00; H04L9/08; H04L9/0816; H04L9/0819; H04L9/083; H04L9/0833; H04L9/0891; H04L2209/00; H04L2209/80
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
95 words
A method of key distribution between a key management controller and at least two communication units in a communication system, comprising the steps of: sending a rekeying message to the at least two communication units; requesting an acknowledgment, delayed beyond a first chance to acknowledge, from each of the at least two communication units at receipt of said rekeying message; and resending said rekeying message to at least one of the at least two communication units when said delayed acknowledgement is not received from said at least one of the at least two communication units.
Claim 2
Independent Claim
95 words
A method of key distribution between a key management controller and at least two communication units in a communication system, comprising the steps of: sending a rekeying message to the at least two communication units; requesting an acknowledgment, delayed beyond a first chance to acknowledge, from each of the at least two communication units at receipt of said rekeying message; and resending said rekeying message to at least one of the at least two communication units when said delayed acknowledgement is not received from said at least one of the at least two communication units.
Claim 3
Dependent Claim
29 words
The method of key distribution of claim 1, wherein said sending step further comprises the step of sending said rekeying message only once within a predetermined period of time.
Claim 4
Dependent Claim
17 words
The method of key distribution of claim 1, further comprising the step of encrypting said rekeying message.
Claim 5
Dependent Claim
16 words
The method of key distribution of claim 1, further comprising the step of encrypting said acknowledgment.
Claim 6
Dependent Claim
15 words
The method of key distribution of claim 1, further comprising the step of key indexing.
Claim 7
Dependent Claim
23 words
The method of key distribution of claim 1, further comprising the step of transmitting keys from the key management controller to a keyloader.
Claim 8
Dependent Claim
18 words
The method of key distribution of claim 1, further comprising the step of distributing a plurality of keys.
Claim 9
Dependent Claim
99 words
A communication system with key distribution between a key management controller and at least two communication units in a communication system, comprising: means for sending a rekeying message to the at least two communication units; means for requesting an acknowledgment, delayed beyond a first chance to acknowledge, from each of the at least two communication units at receipt of said rekeying message; and means for resending said rekeying message to at least one of the at least two communication units when said delayed acknowledgment is not received from said at least one of the at least two communication units.
Claim 10
Dependent Claim
99 words
A communication system with key distribution between a key management controller and at least two communication units in a communication system, comprising: means for sending a rekeying message to the at least two communication units; means for requesting an acknowledgment, delayed beyond a first chance to acknowledge, from each of the at least two communication units at receipt of said rekeying message; and means for resending said rekeying message to at least one of the at least two communication units when said delayed acknowledgment is not received from said at least one of the at least two communication units.
Claim 11
Dependent Claim
27 words
The communication system of claim 8, wherein said means for sending further comprises means for sending said rekeying message only once within a predetermined period of time.
Claim 12
Dependent Claim
14 words
The communication system of claim 8, further comprising means for encrypting said rekeying message.
Claim 13
Dependent Claim
13 words
The communication system of claim 8, further comprising means for encrypting said acknowledgment.
Claim 14
Dependent Claim
12 words
The communication system of claim 8, further comprising means for key indexing.
Claim 15
Dependent Claim
20 words
The communication system of claim 8, further comprising means for transmitting keys from the key management controller to a keyloader.
Claim 16
Dependent Claim
15 words
The communication system of claim 8, further comprising means for distributing a plurality of keys.
References Cited (Backward Citations)
US3749845A
Cited
US4228321A
Cited
US4281216A
Cited
US4440976A
Cited
US4578531A
Cited
US4549308A
Cited
US4605820A
Cited
US4731840A
Cited
US4876716A
Cited
US4882751A
Cited
US4888800A
Cited
US4912762A
Cited
US4927789A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-08 | 1996-03-09 | 1996-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-08 | 2000-03-09 | 2000-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-08 | 2004-03-09 | 2004-09-08 | $7700.00 | Window Closed / Lapsed |