CoARX: a coprocessor for ARX-based cryptographic algorithms

Cryptographic coprocessors are inherent part of modern System-on-Chips. It serves dual purpose - efficient execution of cryptographic kernels and supporting protocols for preventing IP-piracy. Flexibility in such coprocessors is required to provide protection against emerging cryptanalytic schemes and to support different cryptographic functions like encryption and authentication. In this context, a novel crypto-coprocessor, named CoARX, supporting multiple cryptographic algorithms based on Addition (A), Rotation (R) and eXclusive-or (X) operations is proposed. CoARX supports diverse ARX-based cryptographic primitives. We show that compared to dedicated hardware implementations and general-purpose microprocessors, it offers excellent performance-flexibility trade-off including adaptability to resist generic cryptanalysis.