System and methods for data encryption using public key cryptography

• US 5,563,950 A
• Filed: 05/30/1995
• Issued: 10/08/1996
• Est. Priority Date: 03/31/1995
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Easter, Randall J., Merz, William A.
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US08/453,137
• Time in Patent Office: 497 Days
• Field of Search: 380/21, 380/30
• US Class Current: 713/191
• CPC Class Codes: G06F 12/1408 by using cryptography for digital transmission H04L9/00
• CPC Class Codes: G06F 21/72 in cryptographic circuits
• CPC Class Codes: G06F 21/86 Secure or tamper-resistant housings
• CPC Class Codes: G06F 2207/7219 Countermeasures against side channel or fault attacks
• CPC Class Codes: G06F 2211/008 Public Key, Asymmetric Key, Asymmetric Encryption
• CPC Class Codes: H04L 9/0625 with splitting of the data block into left and right halves, e.g. Feistel based algorithms, DES, FEAL, IDEA or KASUMI
• CPC Class Codes: H04L 9/0643 Hash functions, e.g. MD5, SHA, HMAC or f9 MAC
• CPC Class Codes: H04L 9/0897 involving additional devices, e.g. trusted platform module [TPM], smartcard or USB
• CPC Class Codes: H04L 9/302 involving the integer factorization problem, e.g. RSA or quadratic sieve [QS] schemes

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.

Claims

1. A method for establishing private keys in a cryptographic system comprising the steps of:

(a) providing an integrated circuit ("IC") chip having a public key encryption engine and a non-volatile memory, said public key encryption engine being coupled to said non-volatile memory; and

(b) encoding a private key into said non-volatile memory of said IC chip.

2. The method of claim 1, wherein said non-volatile memory comprises a fuse array and wherein said encoding step (b) comprises encoding said private key into said fuse array.

3. The method of claim 2, wherein said encoding step (b) is performed by laser ablation.

4. The method of claim 1, wherein said encoding step (b) further includes encoding a value representative of a public key into said non-volatile memory.

5. The method of claim 4, wherein said value representative of said public key comprises a public key hash value such that said encoding step (b) includes encoding said public key hash value into said non-volatile memory.

6. The method of claim 5, including using said public key hash value is used to verify said public key.

7. The method of claim 1, wherein said encoding step (b) further includes encoding a serial number into said non-volatile memory.

8. The method of claim 1, wherein said providing step (a) comprises providing said IC chip as unencapsulated, and wherein said method further includes encapsulating said IC chip after said encoding step (b).

11. The method of claim 1, wherein the cryptographic system is adapted to perform RSA-type operations in association with said private key.

12. The method of claim 5, wherein said encoding step (b) further includes encoding a serial number into said non-volatile memory, the serial number corresponding to the public and private keys, and wherein the cryptographic system is adapted to perform RSA-type operations in association with said private key.

9. A method for facilitating loading of a proposed public key into an integrated circuit ("IC") chip having a public key encryption engine, said method comprising the steps of:

(a) providing an IC chip having said public key encryption engine and a non-volatile memory, said public key encryption engine being coupled to said non-volatile memory, said non-volatile memory having a value representative of a predetermined public key contained therein; and

(b) verifying said proposed public key against said value representative of said predetermined public key such that said loading of said proposed public key is facilitated.

10. The method of claim 9, wherein said value representative of said predetermined public key comprises a public key hash value such that said providing step (a) includes providing said IC chip having said public key hash value contained therein and said verifying step (b) comprises verifying said proposed public key against said public key hash value.