Biblio

In many industry Internet of Things 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 this article, 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, crossover RO PUF can generate the same shared key for resource-constrained devices, which enables a new application for lightweight key sharing protocols.

FPGA implementation of MD5 hash algorithm is faster than its software counterpart, but a pre-image brute-force attack on MD5 hash still needs 2ˆ(128) iterations theoretically. This work attempts to improve the speed of the brute-force attack on the MD5 algorithm using hardware implementation. A full 64-stage pipelining is done for MD5 hash generation and three architectures are presented for guess password generation. A 32/34/26-instance parallelization of MD5 hash generator and password generator pair is done to search for a password that was hashed using the MD5 algorithm. Total performance of about 6G trials/second has been achieved using a single Virtex-7 FPGA device.