Patent US5559889A successfully refreshed from Google Patents.
US5559889A
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System and methods for data encryption using public key cryptography
Assignee: RPX Corp
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Filing: 1995-03-31
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Granted: 1996-09-24
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Expires: 2015-03-31
Abstract
Abstract An integrated circuit ("IC") chip is provided having both a public key cryptographic engine and a fuse array thereon. The fuse array is hardwired to the public key cryptographic engine and is encoded with a private key for use by the cryptographic engine. Specifically, prior to encapsulation of the IC chip, the fuse array is encoded using a laser ablation process. Upon encapsulation, the private key is permanently sealed and secured within the IC chip. The fuse array may also have a public key hash value and a serial number encoded therein.
Inventors
- 👤 Randall J. Easter
- 👤 William A. Merz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:23
CPC Classifications
G; G06; G06F; G06F21/00; G06F21/70; G06F21/71; G06F21/72; G06F21/86; H; H04; H04L; H04L9/00; H04L9/06; H04L9/0618; H04L9/0625; H04L9/0643; H04L9/08; H04L9/0894; H04L9/0897; H04L9/30; H04L9/3006; H04L9/302; G06F12/00; G06F12/14; G06F12/1408; G06F2207/00; G06F2207/72; G06F2207/7219; G06F2211/00; G06F2211/007; G06F2211/008
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
44 words
An integrated circuit ("IC") chip for use in a cryptographic system, said IC chip comprising: a non-volatile memory containing a private key; and a public key cryptographic engine coupled to said non-volatile memory, said public key cryptographic engine using said private key during operation.
Claim 2
Dependent Claim
44 words
An integrated circuit ("IC") chip for use in a cryptographic system, said IC chip comprising: a non-volatile memory containing a private key; and a public key cryptographic engine coupled to said non-volatile memory, said public key cryptographic engine using said private key during operation.
Claim 3
Dependent Claim
28 words
The system of claim 1, wherein said non-volatile memory comprises a fuse array, said private key being encoded into said fuse array during fabrication of said IC chip.
Claim 4
Dependent Claim
20 words
The system of claim 1, wherein said non-volatile memory further includes a value representative of a public key encoded therein.
Claim 5
Dependent Claim
14 words
The system of claim 3, wherein said value comprises a public key hash value.
Claim 6
Dependent Claim
22 words
The system of claim 1, wherein said non-volatile memory further includes a serial number encoded therein which corresponds to said private key.
Claim 7
Dependent Claim
26 words
The system of claim 1, wherein said IC chip further includes a programmable memory coupled to said public key cryptographic engine for storing a public key.
Claim 8
Dependent Claim
49 words
The system of claim 1, wherein said non-volatile memory comprises a fuse array, said private key being encoded into said fuse array during fabrication of said IC chip, and wherein said fuse array further includes a public key hash value encoded therein for use in verifying a public key.
Claim 9
Dependent Claim
16 words
The system of claim 1, wherein the operation of the cryptographic engine includes an RSA-type operation.
Claim 10
Dependent Claim
35 words
The system of claim 7, wherein said fuse array further includes a serial number encoded therein corresponding to the public and private keys, and wherein the operation of the cryptographic engine includes an RSA-type operation.
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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) | 1999-09-24 | 2000-03-25 | 2000-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-24 | 2004-03-25 | 2004-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-24 | 2008-03-25 | 2008-09-24 | $7700.00 | Window Closed / Lapsed |