Comparative analysis of SRAM memories used as PUF primitives

In this publication we present the results of our investigations into the reliability and uniqueness of Static Random Access Memories (SRAMs) in different technology nodes when used as a Physically Unclonable Function (PUF). The comparative analysis that can be found in this publication is the first ever of its kind, using different SRAM memories in technologies ranging from 180nm to 65nm. Each SRAM memory presents a unique and unpredictable start-up pattern when being powered up. In order to use an SRAM as a PUF in an application, the stability of its start-up patterns needs to be assured under a wide variety of conditions such as temperature and applied voltage. Furthermore the start-up patterns of different memories must be unique and contain sufficient entropy. This paper presents the results of tests that investigate these properties of different SRAM memory technology nodes. Furthermore, it proposes the construction of a fuzzy extractor, which can be used in combination with the tested memories for extracting secure cryptographic keys.