Patent ID: 9009492
Filing Date: 2015-04-14
Classification: G06F,H04L

Abstract:
1. A method for data security, comprising: in a processor having a one-time programmable (OTP) memory, which includes multiple bits and has a current state P defined by the bits of the OTP that have been programmed, receiving new information to be written to a data memory, the new information corresponding to a new state D′ of the data memory; computing a new state P′ of the OTP memory based on the new state D′ of the data memory and the current state of the OTP such that P′=h(D′,P), wherein h is a function that designates one or more un-programmed bits in the state P that are to be programmed based on said computing; selecting which at least one further bit of the bits of the OTP memory is to be programmed; computing a new digital signature over the new information and the new state, wherein the new digital signature depends on a distribution of the programmed bits of the OTP memory and not only on a number of the bits that have been programmed; saving the new information and the new digital signature in the data memory; and after saving the new information and the new digital signature in the data memory, programming the at least one further bit of the OTP memory, the new state of the OTP memory becoming the current state.