A New Efficient Certificateless Short Signature Scheme Using Bilinear Pairings

Recently, the idea of a certificateless short signature (CLSS) scheme has been proposed, as a way of supporting applications or devices in low-bandwidth communication environments, as well as certain devices with limited storage capacity. However, most CLSS schemes have adopted an inefficient and probabilistic hash function, called MapToPoint, making them hard for the computer system designer to implement efficiently. This paper develops a new efficient CLSS scheme using bilinear pairings. The proposed CLSS scheme has the lowest computational cost of signature generation and signature verification, compared to all of the other CLSS schemes. The signature length of our CLSS scheme is only one group element, which means that it is impossible for any CLSS scheme to have a lower signature size than ours. In addition, the MapToPoint operation is not used in our CLSS scheme, so the proposed scheme can be implemented more easily. A formal security analysis is presented, showing that the proposed scheme is secure against both super type I and super type II adversaries. Hence, the proposed scheme is suitable for both limited storage and limited computing capacity devices in low-bandwidth communication environments.