Strongly secure password based blind signature for real world applications

Digital signature is the cryptographic primitive that ensures authentication and nonrepudiation. A password based blind signature can be used in the scenarios, where the participation of both the signer and the user are required. The user requires the authentication of the signer without revealing the message to the signer. This requirement is needed for real world applications such as client server applications in the banking scenario. As per our knowledge, the first password based blind short signature was constructed by Sangeetha et al. in CECC 2013 which ensures the properties unforgeability, blindness and unframeability. But if the password size is very small, it may be susceptible to off-line password guessing attack. In this paper we propose a strongly secure password based blind short signature which solves the off-line password guessing attack. The formal proof of the scheme is reduced to computational Diffie- Hellman(CDH) assumption.