Compact implementations of Grøstl, JH and Skein

Abstract. This work is motivated by future developments of mass mar-kets, where cryptographic infrastructures will become more and more important. One core component of such an infrastructure is a secure cryptographic hash function, which is used for a lot of applications like challenge-response authentication systems or digital signature schemes. Low budget impelementations of such components are therefore very important. In particular, the National Institute of Standards and Technology (NIST) has started a competition for a new secure hash algorithm (SHA-3). New hash functions should outperform older hash functions and thus we study the performance of some of the candidates. A significant comparison between the submitted candidates is only possible, if third party imple-mentations of all proposed hash functions are provided. Of the submitted candidates, we implemented Grøstl, JH and Skein. Our focus on low budget cryptographic solutions makes it natural to investigate possible optimizations for area efficient implementations, and to neglect pure high-throughput considerations. Our results show, that- while all investigated candidates are quite large compared to a compact AES implementation- it is possible to implement all candidates reasonably small. In our evaluation JH is by far the most compact implementation, whereas Skein is the largest one. Our Grøstl implementation on the other hand is smaller than Skein and much faster than both other candidates and easily beats them in the throughput-area ratio by a factor of four