Identity-Based Parallel Key-Insulated Proxy Signature Without Random Oracles

Abstract

Exposure of private keys is the dangerous attack in the public key cryptosystems. We put forward an identity-based parallel key-insulated proxy signature (IBPKIPS) scheme to deal with the problem of key exposure in the identity-based proxy signature system. Our IBPKIPS scheme is secure without random oracles. In the IBPKIPS scheme, we use two different helper keys to renew the temporary private keys. Our IBPKIPS scheme is securer and more flexible than the identity-based proxy signature scheme.