Electrical and Computer Engineering ETDs

Publication Date

Spring 4-14-2017


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.


Physical Unclonable Functions, SRAM PUF, Power Supply ramp time, SRAM cell start-up value, Hardware Security

Document Type




Degree Name

Electrical Engineering

Level of Degree


Department Name

Electrical and Computer Engineering

First Committee Member (Chair)

Payman Zarkesh-Ha

Second Committee Member

James Plusquellic

Third Committee Member

James Aarestad

Third Advisor

Payman Zarkesh-Ha