A Hardware Interface for Hashing Algorithms

The submissions to the SHA-3 competition include a reference implementation in C, built on top of a standard programmer's interface (API). This greatly improves the evaluation process: it enables portability across platforms, and it makes performance comparison of the algorithms easy. For hardware crypto-implementations, such a standard interface does not exist. As a result, the evaluation and comparison of hardware hashing algorithms becomes complex and error prone. The first step to improve the evaluation process for hardware is the definition of an interface. This document describes a general hardware interface for hashing algorithms. The operation of the interface is discussed, and the appendix lists a SHA-256 reference implementation that uses the interface.