Cryptanalysis and Improvement of a Certificateless Short Signature Scheme using Bilinear Pairing

Recently, various certificate-less signature (CLS) schemes have been developed using bilinear pairing to provide authenticity of message. In 2015, Jia-Lun Tsai proposed a certificate-less pairing based short signature scheme using elliptic curve cryptography (ECC) and prove its security under random oracle. However, it is shown that the scheme is inappropriate for its practical use as there is no message signature dependency present during signature generation and verification. Thus, the scheme is vulnerable. To overcome these attacks, this paper aims to present a variant of Jia-Lun Tsai's short signature scheme. Our scheme is secured under the hardness of collusion attack algorithm with k traitors (k CAA). The performance analysis demonstrates that proposed scheme is efficient than other related signature schemes.