IP Library Granted Patent US 7,953,982
Granted Patent B2
US 7,953,982 · App. 12/608,911 · Granted May 31, 2011

Method of authenticating digital signature

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Quick Facts
Patent No.
US 7,953,982
App. No.
12/608,911
Granted
May 31, 2011
Kind
B2
Abstract

A method of authenticating a digital signature is provided. The method includes sending a request from a first entity to a second entity, at least some of the request being digitally signed with a base key by the first entity, receiving, at the first entity, a digital signature and a bit-pattern from the second entity, the digital signature having been generated by the second entity using a variant key to digitally sign at least part of data indicative of a value stored in the second entity which is to be authenticated, the variant key being based on the result of applying a one way function to the base key and the bit-pattern, receiving the data at the first entity, generating, at the first entity, the variant key from the bit-pattern and the base key, and authenticating, at the first entity, the digital signature using the generated variant key. Only the first entity includes the base key and the second entity includes the variant key and the bit-pattern.

Claims (13)

1. A method of authenticating a digital signature comprising the steps of:

sending a request from a first integrated circuit to a second integrated circuit, at least some of the request being digitally signed with a base key by the first integrated circuit;

receiving, at the first integrated circuit, a digital signature and a bit-pattern from the second integrated circuit, the digital signature having been generated by the second integrated circuit using a variant key to digitally sign at least part of data indicative of a value stored in the second which integrated circuit is to be authenticated, the variant key being based on the result of applying a one way function to the base key and the bit-pattern;

receiving the data at the first integrated circuit;

generating, at the first integrated circuit, the variant key from the bit-pattern and the base key; and

authenticating, at the first integrated circuit, the digital signature using the generated variant key,

wherein only the first integrated circuit includes the base key and the second integrated circuit includes the variant key and the bit-pattern.

2. A method according to claim 1 , wherein the first integrated circuit stores information and the data is indicative of a request to be performed on the information.

3. A method according to claim 2 , wherein the information is a value.

4. A method according to claim 1 , wherein the data is indicative of a read instruction.

5. A method according to claim 1 , wherein the data is indicative of a write instruction, the data being indicative of new information to be written.

6. A method according to claim 1 , wherein the data is indicative of a function to be applied to the information.

7. A method according to claim 6 , wherein the function is a decrement or increment function.

Assignments (2)
CHANGE OF NAME Recorded Jun 25, 2014
From: ZAMTEC LIMITED
To: MEMJET TECHNOLOGY LIMITED
Reel/Frame 033244/0276 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 29, 2013
From: SILVERBROOK RESEARCH PTY. LIMITED
To: ZAMTEC LIMITED
Reel/Frame 031510/0531 →