A New Blind Signature and Threshold Blind Signature Scheme from Pairings

An efficient provably secure identity-based blind signature (IBBS) scheme based on bilinear pairings is proposed. Assuming the intractability of the q-Strong Diffie-Hellman problem, our IBBS is unforgeable under adaptive chosen-message and ID attack. Because of avoiding using the inefficient MapToPoint function, our IBBS can offer advantages in runtime over the schemes available. Based on this ID-based blind signature scheme, we describe the first ID-based threshold blind signature (TBS) and show that it has security properties of unforgeability and robustness.