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:
Dec. 25, 2012
Filed:
Dec. 10, 2009
Stéphane Onno, Saint-Gregoire, FR;
Mohamed Karroumi, Rennes, FR;
Antoine Monsifrot, Rennes, FR;
Thomson Licensing, , FR;
Abstract
A method of encrypting compiled computer code instructions to be decrypted instruction by instruction during execution. The computer code instructions are encrypted using a chaining mode so that an encrypted instruction depends on the values of the instruction, the value of the preceding instruction and a pseudo-random number. As it may happen that the instruction can be arrived at from more than one preceding instruction, at least one of the preceding instructions is associated with a random number compensator for use during decryption of the encrypted instruction, so that the decryption of the encrypted instruction yields the same result regardless of which the preceding instruction was. Also provided are an encryption device, a decryption device and method, and a digital support medium storing encrypted compiled computer code instructions.