SRAM Static Entropy Extraction From Every Single Transistor in Unmodified Bitcell and Data Fingerprinting for Provenance Assurance

In this work, an SRAM macro uniquely extracting static entropy from every transistor in unmodified 6T bitcells is presented, achieving for the first time 6-bit/bitcell entropy. When operating as a conventional physically unclonable function (PUF), it achieves a state-of-the-art 296% PUF-to-SRAM capacity ratio without any error correcting code (ECC), retaining its energy and area efficiency at the system level. In addition, the PUF output has native cryptographic-grade quality after one-time self-calibration, uniquely suppressing any entropy post-processing circuitry. As further operating mode, the proposed SRAM macro performs data fingerprinting by exploiting its unique data-dependent response. Data fingerprinting represents an additional layer of security supporting provenance assurance of data and user authentication in real time or in retrospect. Competitive 134-F²/bit area efficiency is demonstrated in 28 nm with minor modification of conventional SRAM periphery.