Tamper Sensor Using a Metastable Magnetic Array

This Phase I SBIR program will design and manufacture a unique anti-tamper device determines when adversarial acquisition or exploitation of U.S. analog and/or digital circuit components has been made by monitoring circuit activity. The sensor operates as a sensitive switch. The state of the switch is determined by the configuration of an array of lithographically defined magnetic elements. If the anti-tamper device is enabled, activity in sensitive circuits produces a current pulse and a magnetic field that realigns an element in the array from an initially metastable configuration. The state of the switch is read electrically and can be used to trigger an alarm or the destruction of the device. The array's design prevents the reinitializing of the magnetic elements into the original configuration without direct access to the device or the knowledge of a predetermined programming current value. External magnetic fields, above an ambient threshold, will trigger the sensor but cannot be used to reset the device. The proposed device combines emerging magnetic storage and sensor technologies with state-of-the-art microelectronic manufacturing. This allows the device to be very small, highly adaptable, and reliable. It can be put into a custom package or fully integrated into other circuit components at the wafer level.