Traitor traceable signature scheme
Y. Watanabe, Yuliang Zheng, H. Imai · 2002
A new signature scheme, traitor traceable signature scheme is presented, which allows the signer to convince any arbiter of the recipient's infringement, if the recipient distributes illegally the signature which he got. We use the techniques of a proof of knowledge of discrete logarithm, identification of double spender in an off-line electronic cash, and a signcryption scheme. Our scheme consists of a 3-move and it is more compact and efficient compared with the previous scheme, due to the elimination of the cumbersome cut-and-choose like techniques. Moreover, our accusation protocol does not require the private-key of the recipient of the signature, i.e., the signer can convince any arbiter of the recipient's infringement without the help of the original recipient.