Feedback reinforced accelerated aging for improved physical unclonable function stability

Abstract

The Pre-Amplifier Physical Unclonable Function (Pre-Amp PUF) is a promising new PUF topology with a low native array bit error rate (BER). Stabilization techniques to reduce the BER exist but often require storing the location of repeatable bit locations in non-volatile memory. This ‘helper data’ is expensive in chip area and power. In this paper we study for the first time the effects of aging on the Pre-Amp PUF design and its ability to self-reinforce the initial preferred state automatically. We then propose a novel Feedback Reinforced Accelerated Aging (FRAA) technique wherein the Pre-Amp PUF key error rate can be reduced to “zero” with no external user interaction required. Data is gated from leaving the PUF design during the FRAA process thereby keeping the PUF enrollment process dedicated to the end user. Statistical modeling and aging analysis are performed using a 5-nm FinFET process development kit.