US5144664A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for upgrading terminals to maintain a secure communication network
Assignee: Arris Technology Inc
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Filing: 1990-11-16
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Granted: 1992-09-01
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Expires: 2010-11-16
Abstract
Abstract A secure communication network serves a plurality of terminals grouped into different security categories. Each terminal includes a replaceable security element containing a security algorithm specific to the security category to which the terminal is assigned. Upon the breach of a particular security version, the security elements in the affected category are replaced with new elements containing a different algorithm. The security elements are relatively low cost, and can be replaced on an as needed or periodic basis to maintain system security.
Inventors
- 👤 James N. Esserman
- 👤 Jerrold A. Heller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:20
CPC Classifications
H; H04; H04N; H04N21/00; H04N21/20; H04N21/23; H04N21/234; H04N21/2347; H04N7/00; H04N7/16; H04N7/162
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
103 words
A system for revising a set of terminals in a communication network to maintain signal security comprising: a headend for transmitting signals; encryption means operatively associated with said headend for encrypting said signals according to a plurality of encryption algorithms, each algorithm associated with a different subset of terminals authorized to receive said signals; means for selectively terminating the transmission of said signals under a particular algorithm; means for providing a replacement algorithm in said encryption means for use instead of the terminated algorithm; and security means for providing a corresponding replacement algorithm to the subset of terminals associated with the terminated algorithm.
Claim 2
Independent Claim
103 words
A system for revising a set of terminals in a communication network to maintain signal security comprising: a headend for transmitting signals; encryption means operatively associated with said headend for encrypting said signals according to a plurality of encryption algorithms, each algorithm associated with a different subset of terminals authorized to receive said signals; means for selectively terminating the transmission of said signals under a particular algorithm; means for providing a replacement algorithm in said encryption means for use instead of the terminated algorithm; and security means for providing a corresponding replacement algorithm to the subset of terminals associated with the terminated algorithm.
Claim 3
Dependent Claim
39 words
A system in accordance with claim 1 further comprising: a cryptographic key associated with each algorithm; and means for transmitting each key in an encrypted form to the terminals associated with the algorithm to which the key is associated.
Claim 4
Dependent Claim
44 words
A system in accordance with claim 2 wherein a different cryptographic key is associated with each one of said algorithms; and means are provided for replacing the cryptographic key associated with said terminated algorithm with a new cryptographic key associated with the replacement algorithm.
Claim 5
Dependent Claim
47 words
A system in accordance with claim 1 wherein: said security means comprises a replaceable security element associated with each terminal in the system; and the replaceable security element for each terminal in a subset contains a decryption algorithm corresponding to the encryption algorithm associated with the subset.
Claim 6
Dependent Claim
23 words
A system in accordance with claim 4 wherein: said replaceable security elements process said signals to provide working keys for their respective terminals.
Claim 7
Dependent Claim
14 words
A system in accordance with claim 5 wherein: the working keys are all identical.
Claim 8
Dependent Claim
15 words
A system in accordance with claim 4 wherein said decryption algorithm is implemented in hardware.
Claim 9
Dependent Claim
31 words
A system in accordance with claim 1 wherein each terminal comprises a default decryption algorithm for use in decrypting received signals encrypted by a corresponding default encryption algorithm at the headend.
Claim 10
Dependent Claim
47 words
A terminal for use in the system of claim 1 comprising: means for receiving said signals; and a replaceable security element operatively associated with said receiving means for decrypting received signals; wherein said replaceable security element comprises a decryption algorithm corresponding to one of said encryption algorithms.
Claim 11
Dependent Claim
29 words
A terminal in accordance with claim 9 further comprising: a default decryption algorithm for use in decrypting received signals encrypted by a corresponding default encryption algorithm at the headend.
Claim 12
Dependent Claim
59 words
A terminal in accordance with claim 9 further comprising: means for receiving and storing a cryptographic key associated with said decryption algorithm; and means for receiving and storing a replacement cryptographic key upon replacement of said security element with a new security element; wherein said replacement key is associated with a new decryption algorithm in the new security element.
Claim 13
Independent Claim
80 words
A method for revising a set of terminals to recover from security compromises in a secure communication network comprising the steps of: transmitting encrypted signals to different subsets of terminals using a different encryption algorithm for each subset; providing the terminals in each subset with a corresponding decryption algorithm; providing a replacement encryption algorithm for a particular subset upon the occurrence of an event; and providing a corresponding replacement decryption algorithm to each of the terminals in said particular subset.
Claim 14
Independent Claim
80 words
A method for revising a set of terminals to recover from security compromises in a secure communication network comprising the steps of: transmitting encrypted signals to different subsets of terminals using a different encryption algorithm for each subset; providing the terminals in each subset with a corresponding decryption algorithm; providing a replacement encryption algorithm for a particular subset upon the occurrence of an event; and providing a corresponding replacement decryption algorithm to each of the terminals in said particular subset.
Claim 15
Dependent Claim
32 words
A method in accordance with claim 12 comprising the further step of: providing said replacement decryption algorithm in replaceable security elements for distribution to each of the terminals in said particular subset.
Claim 16
Dependent Claim
23 words
A method in accordance with claim 13 wherein: the security elements process the encrypted signals to provide working keys for their respective terminals.
Claim 17
Dependent Claim
14 words
A method in accordance with claim 14 wherein: the working keys are all identical.
Claim 18
Dependent Claim
21 words
A method in accordance with claim 13 wherein said event is a compromise of the security element for said particular subset.
Claim 19
Dependent Claim
40 words
A method in accordance with claim 12 wherein said transmitted signals comprise a different cryptographic key for each different encryption algorithm, said method comprising the further step of: providing a new cryptographic key for use with said replacement encryption algorithm.
Claim 20
Dependent Claim
33 words
A method in accordance with claim 12 comprising the further step of: providing each terminal with a default decryption algorithm for use in decrypting received signals encrypted by a corresponding default encryption algorithm.
Claim 21
Independent Claim
72 words
A system for revising a set of terminals in a communication network to maintain signal security comprising: means for encrypting signals for transmission; a headend operatively associated with said encryption means for transmitting said signals to different subsets of said terminals; and a different set of replaceable security elements associated with each subset of terminals, each set of security elements providing a different security algorithm for decrypting said signals at the terminals.
Claim 22
Independent Claim
72 words
A system for revising a set of terminals in a communication network to maintain signal security comprising: means for encrypting signals for transmission; a headend operatively associated with said encryption means for transmitting said signals to different subsets of said terminals; and a different set of replaceable security elements associated with each subset of terminals, each set of security elements providing a different security algorithm for decrypting said signals at the terminals.
Claim 23
Dependent Claim
32 words
A system in accordance with claim 19 wherein each set of security elements uses a different decryption algorithm corresponding to one of a plurality of encryption algorithms used by said encrypting means.
Claim 24
Dependent Claim
27 words
A system in accordance with claim 19 wherein each set of security elements uses a different technique to protect information contained in the security elements from discovery.
Claim 25
Dependent Claim
22 words
A system in accordance with claim 21 wherein said techniques destroy a security element upon an attempt to discover said information therefrom.
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) | 1995-09-01 | 1996-03-02 | 1996-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-01 | 2000-03-02 | 2000-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-01 | 2004-03-02 | 2004-09-01 | $7700.00 | Window Closed / Lapsed |