Patent ID: 8566791
Filing Date: 2013-10-22
Classification: G06F

Abstract:
1. A method of verifying integrity of program code embedded in an accessory, said accessory having a memory device for storing the program code and data associated with the program code, all unused memory space of the memory device being filled with random data, a host having access to a memory image of the memory device, said method comprising the steps of: sending a list of memory address ranges to the accessory, said memory address ranges each being defined by end points unpredictable to the accessory, said list specifying said memory address ranges in a sequence unpredictable to the accessory; receiving a value from the accessory, said value being generated from and representative of values of memory at memory addresses in said memory address ranges arranged according to said sequence specified in said list; producing an expected value from a copy of the memory image and said list; and comparing said value received from the accessory with said expected value; wherein the integrity of the program code is verified if said received value is equivalent to said expected value.