The effect of power supply ramp time on SRAM PUFs

Abstract

Physical unclonable functions (PUFs) are security primitives that exploit the device mismatches. PUFs are a promising solution for hardware cryptography and key storage. They are used in many security applications including identification, authentication and key generation. SRAM is one of the popular implementations of PUFs. SRAM PUFs offer the advantage, over other PUF constructions, of reusing resources (memories) that already exist in many designs. In this thesis, for the first time, it is demonstrated that the start-up value of an SRAM PUF could be different depending on the SRAM power supply rising time. An analytical model has been developed to determine the range for the power supply ramp time that affects the SRAM PUF start-up value. It has been found that there are two regions of operation. The generated key could possibly be different from one region to another. An SRAM test chip was designed and fabricated using Tower Jazz's 180 nanometer Silicon Germanium (SiGe) Bipolar/CMOS (BiCMOS) process. Based on our vii measured data, using the appropriate rising time can decrease the number of flipping bits by 5%. Both simulation and silicon results confirms the analytical model.

Data Remanence Based Approach towards Stable Key Generation from Physically Unclonable Function Response of Embedded SRAMs using Binary Search

“…Ziyang et al, [23] have also used different power-up scenarios and analyzed the results for 256 bits of SRAM PUF. Elshafiey [24] also stated that the startup values of SRAM PUF are affected by the rising time of power supply. They implemented a 180nm Silicon-Germanium Bipolar/CMOS (BiCMOS) SRAM and confirmed the results.…”

Innovative Countermeasures to Defeat Cyber Attacks Against Blockchain Wallets

“…Innovative procedures have been developed to acquire such fingerprints, including singular points called flipping bits. Flipping bits [18] cannot be cloned by software. This technique ensures that devices received by clients are authentic.…”

“…The paper [18] demonstrates the effect of voltage ramps on the PUF SRAM. Given a ramp V(t)= t VDD/T (i.e., slope=VDD/T), flipping bits are observed for slopes of high values.…”