US5559889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System and methods for data encryption using public key cryptography
Assignee: RPX Corp
•
Filing: 1995-03-31
•
Granted: 1996-09-24
•
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 06:55
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.
References Cited (Backward Citations)
US4723284A
Cited
US4658093A
Cited
US4731841A
Cited
JPH02248131A
Cited
US5159633A
Cited
US5144665A
Cited
JPH03179842A
Cited
US5199070A
Cited
US5295188A
Cited
US5249230A
Cited
US5315658B1
Cited
US5315658A
Cited
US5224166A
Cited
US5412721A
Cited
US5368468A
Cited
US5414772A
Cited
US5343527A
Cited
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 |