Identity based designated multi-confirmer signature: a new type signature

The identity based encryption scheme proposed by Boneh and Franklin in 2001 using bilinear pairings is the only practical identity based public-key encryption scheme so far. In this paper we firstly present the concept of designated multi-confirmer signature and give a concrete identity based scheme. Our scheme is compatible with Boneh and Franklin encryption scheme and can be used as identity based designated confirmer signature (when n = 1).