Patent ID: 7801869
Filing Date: 2010-09-21
Classification: D04H,G06F,G11B

Abstract:
1. A method for monitoring replaceable portions of a device, said replaceable portions each having a unique identifier associated therewith, said method comprising: said device obtaining from a new portion, a partial list of unique identifiers stored thereon, said partial list having been chosen from a master list of unique identifiers at random, wherein each of said identifiers in said master list is given a weight, and wherein said weight dictates the likelihood of said identifier being chosen from said master list, said partial list having been combined with a unique identifier associated with said new portion and digitally signed to generate a digital signature binding said partial list to said new portion, said digital signature being stored on said new portion; said device obtaining said digital signature from said new portion and verifying said digital signature; and if said digital signature is verified, said device comparing said unique identifier associated with said new portion with a locally stored list of identifiers and said partial list and rejecting incorporation of said new portion if said unique identifier associated with said new portion is found.