Efficient and short certificateless signature

Abstract

A certificateless signature (CLS) scheme with short signature size is proposed in this paper. Our scheme is as efficient as BLS short signature scheme in both communication and computation, and therefore turns out to be more efficient than other CLS schemes proposed so far. We provide a rigorous security proof of our scheme in the random oracle model. The security of our scheme is based on the k-CAA hard problem and a new discovered hard problem, namely, modified k-CAA problem. Our scheme can be applied to systems where signatures are typed in by human or systems with low-bandwidth channels and/or low-computation power, such as PDAs or cell phones. © 2008 Springer Berlin Heidelberg.