Abstract:

A new identity-based partially blind signature scheme was proposed. Assuming the intractability of the q-Strong Diffie-Hellman problem, the scheme was proved to be unforgeable in the random oracle model. Compared with other existing schemes, the new scheme performs more efficient in computation because it doesn’t need inefficient MapToPoint hash function and only needs one pairing computation. Based on the scheme mentioned above, a restrictive partially blind signature is proposed and proved to be efficient, correct, unforgeable, as well as restrictive and partially blind.

Key words: identity-based, q-strong Diffie-Hellman problem, partially blind signature, restrictive partially blind signature