Efficient Certificate-Based and Randomized Signature from Pairings

Most of pairing-based schemes need two or more operations of pairings. To find an efficient randomized certificate-based signature from pairings, by constructing a fraction such that a random element of the gap Diffie-Hellman group is included in the numerator and the sum of the master key and the output of the hash function is included in the denominator, a new signature scheme from pairings is proposed, in which only one operation of pairings is used. Under the hardness assumption of CDHP, the scheme can be proved to be secure in random oracle. The new signature is an efficient pairing-based one, since there is only one operation of pairings in it. The new randomized signature is short. On the other hand, the security proof has a tight reduction.