Unified In-Memory Dynamic TRNG and Multi-Bit Static PUF Entropy Generation for Ubiquitous Hardware Security

Abstract

This work introduces unified in-memory True Random Number Generator (TRNG) and Physically Unclonable Function (PUF) for complete and inexpensive key generation within an SRAM array. TRNG is based on time-to-digital conversion of jitter accumulated at bitline discharge from leakage. Multi-bit per bitcell PUF is achieved by binning the discharge rate difference of bitline pairs. A 28 nm testchip shows TRNG at 16,000 F2 area per output stream, and 2-bit/bitcell PUF with 6.4 Gbps, 78 fJ/bit energy.