The Boeing Company
Tamper resistant counters

Abstract:

A method of persistently storing event counts includes generating, using a secret cryptographic key, a sequence of numbers arranged in a pseudorandom order. The sequence of numbers is indicative of a sequence of addresses of cells in an array of cells. Each cell in the array of cells is programmable from an initial state to a programmed state to persistently encode data indicative of counter values associated with a particular event. The method also includes comparing addresses of cells having the programmed state with the sequence of addresses to determine whether a tampering event occurred at the array of cells. The method further includes, based on the determination, authenticating the array of cells or performing a countermeasure.