One-Time Signatures Revisited: Have They Become Practical?

One-time signatures have been known for more than two decades, and have been studied mainly due to their theoretical value. Recent works motivated us to examine the practical use of one-time signatures in high-performance applications. In this paper we describe FMTseq — a signature scheme that merges recent improvements in hash tree traversal into Merkle’s one-time signature scheme. Implementation results show that the scheme provides a signature speed of up to 35 times faster than a 2048-bit RSA signature scheme, for about one million signatures, and a signature size of only a few kilobytes. We provide an analysis of practical parameter selection for the scheme, and improvements that can be applied in more specific scenarios.