Patent ID: 8195945
Filing Date: 2012-06-05
Classification: G06F,G11C

Abstract:
1. A method for writing and updating digital certificates in flash memory to enhance tampering proof characteristics of the memory comprising the steps of: erasing at least one erase-write block of a flash memory that has predefined erase-write blocks and write-read blocks, defining a plurality of memory slots within said at least one erased erase-write block wherein each memory slot has a commencing address comprising a binary “0”- or a binary “1” bit pattern, writing a first digital certificate in a first one of said memory slots and writing a second digital certificate in a second one of said memory slots, defining a certificate slot address pointer as being the commencing address of said first memory slot; said slot address pointer to be used by a verification program to fetch a current valid certificate; and updating said certificate slot address pointer when the first digital certificate expires by replacing said “0”- or “1”-bit pattern of said pointer with a “1”- or a “0” bit pattern, respectively, causing the address pointer to point on the commencing address of said second memory slot when the first digital certificate expires to minimize a period of time during which the memory is exposed to security attack during digital certificate update; and wherein the certificates authenticate a computer program when verified by the verification program that is associated with the computer program.