Patent ID: 8294577

Claim:
A tamper sensing system mounted with respect to a protected structure so as to have corresponding stress changes occur therein in response to selected kinds of tamperings with said protected structure, said system comprising: a first pair of stress affected magnetoresistive memory devices each capable of having a magnetic material layer therein established in a selected one of a pair of alternative magnetization states if in a first kind of stress condition and of being established in a remaining magnetization state if in an alternative second kind of stress condition and with said magnetic material layer in each having a magnetization in a first direction in one of said pair of alternative magnetization states and in a second direction in that remaining one of said pair of magnetization states, said first pair of stress affected magnetoresistive memory devices being mounted together such that at least one of said first and second directions thereof at least in part parallels an aligning direction that parallels at least in part at least one of said first and second directions of that other one remaining; and a first magnetizing electrical conductor extending adjacent to each of said first pair of stress affected magnetoresistive memory devices such that providing an electrical current therethrough to generate a corresponding magnetic field thereabout establishes said magnetic material layer of each of said first pair of stress affected magnetoresistive memory devices in that one of said pair of alternative magnetization states thereof so as to have said magnetization corresponding thereto be oppositely directed with respect to said magnetization of that other magnetic material layer insofar as components thereof substantially parallel to said aligning direction when each of said first pair of stress affected magnetoresistive memory devices is provided with a first kind of stress condition.