Electrical and Computer Engineering ETDs

Publication Date

Spring 4-8-2020


A Physical Uncloneable Function (PUF) is an integrated circuit hardware primitivethat is designed to leverage naturally occurring variations to produce a randombitstring. The Aribiter (ARB) PUF is one of the first to be described in the literature.It derives its entropy from variations that occur in the delays of identically configuredlogic paths. The ARB PUF uses a phase comparator to decide which path of a pairis faster under a given challenge, and generates a 0 or 1 as a response indicatorbit. Unfortunately, the ARB PUF is not reliable, requiring error correction in caseswhere the sequence of response bits (the bitstring) needs to be reproduced. In thisproposal, a test structure is described, called a time-to-digital converter (TDC) thatis capable of measuring the actual delays of the paths. This type of ’soft’ informationcan be used to improve the reliability of the ARB PUF. Data obtained from a setof chips fabricated in IBM’s 90 nm technology, and collected across 9 temperature-voltage (TV) corners, is used to demonstrate its effectiveness.iv Current PUF designs are typically implemented in silicon like the ARB PUFor utilize variations found in commercial off-the-shelf (COTS) parts. Because ofthis, existing designs are insufficient for the authentication of Printed Circuit Boards(PCBs). In this thesis, we also propose a novel PUF design that leverages boardvariations in a manufactured PCB to generate unique and stable identifiers (IDs) foreach PCB. In particular, a single copper trace is used as a source of randomnessfor bitstring generation. The trace connects three notch filter structures in series,each of which is designed to reject specific but separate frequencies. The bitstringsgenerated with both the ARB PUF and the PCB PUF are evaluated using statisticaltests which measure randomness, uniqueness and reliability.

Document Type




Degree Name

Computer Engineering

Level of Degree


Department Name

Electrical and Computer Engineering

First Committee Member (Chair)

Jim Plusquellic

Second Committee Member

Payman Zarkesh-Ha

Third Committee Member

Jedidiah Crandall

Third Advisor

Todd Bauer