Physical Unclonable Function-based Key Sharing for IoT Security

TL;DR

This paper introduces a novel PUF-based key sharing method for IoT devices that enables resource-constrained devices to share the same cryptographic key, enhancing lightweight security protocols.

Contribution

It proposes a new PUF-based key sharing technique using LUT-based interstage crossing structures in RO PUFs, allowing shared keys among devices.

Findings

Enables shared key generation for resource-constrained IoT devices.

Uses LUT-based interstage crossing structures for flexible configuration.

Facilitates lightweight key sharing protocols in IIoT applications.

Abstract

In many Industry Internet of Things (IIoT) applications, resources like CPU, memory, and battery power are limited and cannot afford the classic cryptographic security solutions. Silicon Physical Unclonable Function (PUF) is a lightweight security primitive that exploits manufacturing variations during the chip fabrication process for key generation and/or device authentication. However, traditional weak PUFs such as Ring Oscillator (RO) PUF generate chip-unique key for each device, which restricts their application in security protocols where the same key is required to be shared in resource-constrained devices. In order to address this issue, we propose a PUF-based key sharing method for the first time. The basic idea is to implement one-to-one input-output mapping with Lookup Table (LUT)-based interstage crossing structures in each level of inverters of RO PUF. Individual customization on configuration bits of interstage crossing structure and different RO selections with challenges bring high flexibility. Therefore, with the flexible configuration of interstage crossing structures and challenges, CRO PUF can generate the same shared key for resource-constrained devices, which enables a new application for lightweight key sharing protocols.