Chip-to-Chip Authentication Method Based on SRAM PUF and Public Key Cryptography

Abstract

In today’s globalized integrated circuit (IC) ecosystem, untrusted foundries are often procured to build critical systems since they offer state-of-the-art silicon with the best performance available. On the other hand, ICs that originate from trusted fabrication cannot match the same performance level since trusted fabrication is often available on legacy nodes. Split-Chip is a dual-IC approach that leverages the performance of an untrusted IC and combines it with the guaranties of a trusted IC. In this paper, we provide a framework for chip-to-chip authentication that can further improve a Split-Chip system by protecting it from attacks that are unique to Split-Chip. A hardware implementation that utilizes an SRAM-based PUF as an identifier and public key cryptography for handshake is discussed. Circuit characteristics are provided, where the trusted IC is designed in a 28-nm CMOS technology and the untrusted IC is designed in an also commercial 16-nm CMOS technology. Most importantly, our solution does not require a processor for performing any of the handshake or cryptography tasks, thus being not susceptible to software vulnerabilities and exploits.