System and method for verifying digital signatures on certificates

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US007716139B2

United States Patent

Brown et al.

(io) Patent No.: (45) Date of Patent:

US 7,716,139 B2 May 11, 2010

SYSTEM AND METHOD FOR VERIFYING DIGITAL SIGNATURES ON CERTIFICATES

Inventors: Michael K. Brown, Kitchener (CA);

Michael S. Brown, Waterloo (CA)

Assignee: Research In Motion Limited, Waterloo, Ontario (CA)

Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 1076 days.

Appl.No.: 10/975,988

Filed: Oct. 29, 2004

Prior Publication Data

US 2006/0095388 Al May 4, 2006

Int. CI.

G06Q 99/00 (2006.01)

U.S. CI 705/76; 705/65; 705/67;

705/75; 705/78; 713/155; 713/156; 713/176

Field of Classification Search 705/50 79;

713/155, 156, 176 See application file for complete search history.

References Cited

U.S. PATENT DOCUMENTS

713/168

713/170

A system and method for verifying a digital signature on a certificate, which may be used in the processing of encoded messages. In one embodiment, when a digital signature is successfully verified in a signature verification operation, the public key used to verify that digital signature is cached. When a subsequent attempt to verify the digital signature is made, the public key to be used to verify the digital signature is compared to the cached key. If the keys match, the digital signature can be successfully verified without requiring that a signature verification operation in which some data is decoded using the public key be performed.

19 Claims, 10 Drawing Sheets

FOREIGN PATENT DOCUMENTS

TW 00505905 10/2002

WO 02/21464 3/2002

WO 02/37245 5/2002

WO 03/063413 7/2003

OTHER PUBLICATIONS

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* cited by examiner