Two improved partially blind signature schemes from bilinear pairings

A blind signature scheme is a protocol for obtaining a digital signature from a signer, but the signer can neither learn the messages he/she sign nor the signatures the recipients obtain afterwards. Partially blind signature is a variant such that part of the message contains preagreed information (agreed by the signer and the signature requester) in unblinded form, while threshold blind signature distributes the signing power to a group of signers such that a signature can only be produced by interacting with a predetermined numbers of signers. In this paper, we propose a threshold partially blind signature scheme from bilinear pairings and an ID-based partially blind signature scheme, which are provably secure in the random oracle model. To the best of authors' knowledge, we give the first discussion on these two notions. © Springer-Verlag Berlin Heidelberg 2005.link_to_subscribed_fulltex