A system-level architecture for hash message authentication code

Modern network-based applications continuously raise the demand for secure data communications. This demand has motivated the development of new cryptographic standards and encryption algorithms. The hash message authentication code (HMAC) has been adopted as a standard for robust authentication with enhanced security features. HMAC makes use of wellknown hash functions. Hash function security levels have been considerably improved by introducing a new standard, named SHA-2. The major strength of the new SHA-2 standard relies in its variable-size hash value (256, 384, 512 bits). In this paper, a new system architecture is proposed to implement HMAC using SHA-2 hash functions. This architecture aims to maximize the throughput and it follows a CODESIGN approach, where the critical computations of SHA-2 hash algorithms are implemented in hardware, while the non-critical ones are kept in software. Finally, the proposed architecture is very flexible and can efficiently implement complex digital signature algorithms and keyed-hash message authentication codes.