Method and system for writing information in a data carrier making it possible to later certify the originality of this information
Patent 5796835 Issued on August 18, 1998. Estimated Expiration Date: May 7, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
The invention consists of writing at least one piece of information I! and an image I'! thereof into the accessible memory zone Ac of a portable object (1). This image I'! is obtained by implementing a program of encipherment of the information I!. This program takes into account at least the one piece of information I!, a first datum Ks! that is external to the portable object and furnished to encipherment circuits (21) under the control of the person writing the information, and a second datum Sid! that is diversified for each portable object (1). Later certification consists of verifying that an image I'! has been obtained with the aid of the first and second data, so as to deduce from this that the associated information I! is original.