The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 24, 2009
Filed:
Jan. 05, 2004
Michael Ignaszewski, Fremont, CA (US);
Michael Ignaszewski, Fremont, CA (US);
Sigma Designs, Inc., Milpitas, CA (US);
Abstract
The present invention increases the difficulty of reverse engineering sensitive information protected by an encryption algorithm by increasing the difficulty associated with tracing the code that generates the key or the encryption algorithm. This is accomplished by generating the key, used to encrypt and decrypt the sensitive information, as a function of the program instruction values of the procedures used to generate the key and perform the decryption of the sensitive information. Thus, if the key generation code or the decryption code is modified (such as (but without limitation) by placement of a breakpoint, a trace function, or a halt instruction in the code) the resulting key will be different from the key used to encrypt the sensitive information and the decryption attempt will fail.