Time Stamped Proxy Blind Signature Scheme
With Proxy Revocation Based on
Discrete Logarithm Problem

Abstract

Proxy blind signature combines both the properties of blind signature and proxy signature. In a proxy blind signature scheme, the proxy signer is allowed to generate a blind signature on behalf of the original signer. It is a protocol played by three parties in which a user obtains a proxy signer’s signature for a desired message and the proxy signer learns nothing about the message. During the verification of a proxy blind signature scheme, the verifier cannot get whether signing is within the delegation period or after delegation period. In this thesis a time stamped proxy blind signature scheme with proxy revocation is proposed which records the time stamp during the proxy signing phase and satisfies all the security properties of proxy blind signature i.e distinguishability, nonrepudiation, unforgeability, verifiability, identifiability, unlinkability, prevention of misuse. In a proxy revocation scheme, the original signer can terminate the delegation power of a proxy signer before the completion of delegation period. Proxy blind signature has wide applications in real life scenarios, such as, e-cash, e-voting and e-commerece applications.