Novel Transistor Resistance Variation-based Physical Unclonable Functions with On-Chip Voltage-to-Digital Converter Designed for Use in Cryptographic and Authentication Applications
type: CreativeWork
description: Security mechanisms such as encryption, authentication, and feature activation depend on the integrity of embedded secret keys. Currently, this keying material is stored as digital bitstrings in non-volatile memory on FPGAs and ASICs. However, secrets stored this way are not secure against a determined adversary, who can use specialized probing attacks to uncover the secret. Furthermore, storing these pre-determined bitstrings suffers from the disadvantage of not being able to generate the key only when needed. Physical Unclonable Functions (PUFs) have emerged as a superior alternative to this. A PUF is an embedded Integrated Circuit (IC) structure that is designed to leverage random variations in physical parameters of on-chip components as the source of entropy for generating random and unique bitstrings. PUFs also incorporate an on-chip infrastructure for measuring and digitizing these variations in order to produce bitstrings. Additionally, PUFs are designed to reproduce a bitstring on-demand and therefore eliminate the need for on-chip storage. In this work, two novel PUFs are presented that leverage the random variations observed in the resistance of transistors. A thorough analysis of the randomness, uniqueness and stability characteristics of the bitstrings generated by these PUFs is presented. All results shown are based on an exhaustive testing of a set of 63 chips designed with numerous copies of the PUFs on each chip and fabricated in a 90nm nine-metal layer technology. An on-chip voltage-to-digital conversion technique is also presented and tested on the set of 63 chips. Statistical results of the bitstrings generated by the on-chip digitization technique are compared with that of the voltage-derived bitstrings to evaluate the efficacy of the digitization technique. One of the most important quality metrics of the PUF and the on-chip voltage-to-digital converter, the stability, is evaluated through a lengthy temperature-voltage testing over the range of…
abstract: Security mechanisms such as encryption, authentication, and feature activation depend on the integrity of embedded secret keys. Currently, this keying material is stored as digital bitstrings in non-volatile memory on FPGAs and ASICs. However, secrets stored this way are not secure against a determined adversary, who can use specialized probing attacks to uncover the secret. Furthermore, storing these pre-determined bitstrings suffers from the disadvantage of not being able to generate the key only when needed. Physical Unclonable Functions (PUFs) have emerged as a superior alternative to this. A PUF is an embedded Integrated Circuit (IC) structure that is designed to leverage random variations in physical parameters of on-chip components as the source of entropy for generating random and unique bitstrings. PUFs also incorporate an on-chip infrastructure for measuring and digitizing these variations in order to produce bitstrings. Additionally, PUFs are designed to reproduce a bitstring on-demand and therefore eliminate the need for on-chip storage. In this work, two novel PUFs are presented that leverage the random variations observed in the resistance of transistors. A thorough analysis of the randomness, uniqueness and stability characteristics of the bitstrings generated by these PUFs is presented. All results shown are based on an exhaustive testing of a set of 63 chips designed with numerous copies of the PUFs on each chip and fabricated in a 90nm nine-metal layer technology. An on-chip voltage-to-digital conversion technique is also presented and tested on the set of 63 chips. Statistical results of the bitstrings generated by the on-chip digitization technique are compared with that of the voltage-derived bitstrings to evaluate the efficacy of the digitization technique. One of the most important quality metrics of the PUF and the on-chip voltage-to-digital converter, the stability, is evaluated through a lengthy temperature-voltage testing over the range of…
author: Chakraborty, Raj
language: English
keywords: Physical unclonable functions, cryptography, hardware security, authentication, temperature stability, bitstring
date published: 2014-09-12T07:00:00Z
date modified: 2026-07-24T05:27:10Z
provider: University of New Mexico
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of New Mexico