Factoring-Based Proxy Signature Schemes with Forward-Security

The property of forward-security can be used to reduce the potential damages caused by key exposure. However, none of the existing proxy signature schemes has taken forward-security into consideration. And most proxy signature schemes are based on discrete logarithm problem. In this paper, we first present a forward-secure proxy signature scheme based on factoring problem. Next, we present a forward-secure threshold proxy signature scheme.