In the literature, several pairing-based blind signature schemes have been put forwarded using identity-based cryptography. However, the private key escrow problem of these schemes makes them unsuitable in practical environments because the private key generator computes signer private key using signer public identity. Therefore, an untrusted/semitrusted private key generator may perform malicious activity on behalf of the signer. We took the advantage of certificateless public key cryptography and constructed a robust and efficient certificateless blind signature (CL-BS) scheme using bilinear pairing. Furthermore, the probabilistic map-to-point hash function, which requires more computation time than the execution time of an elliptic curve scalar point multiplication, is circumvented in our scheme. We found that our scheme is unlinkable and provably secure against the adaptive chosen message and identity adversaries. From the perspective of computational costs, our scheme is more efficient and secure than other related schemes.
Motivation and contributionIn the literature, several blind signature schemes are designed based on IBC. However, very less number of pairing-based certificateless blind signature (CL-BS) schemes [6][7][8] have been noticed. We observed that the schemes devised in [6][7][8][9][10][11][12][13] are based on the probabilistic map-to-point hash function [4], which needs more computation time than the time needed to execute an elliptic curve scalar point multiplication operation. In addition,