Secure Key-Insulated Proxy Signature Scheme for Mobile Agent

It is expected that mobile agent will be widely used for electronic commerce as an important key technology. If a mobile agent may act as a proxy signer to produce signa- tures on behalf of the agent owner autonomously, it will in- crease efficiency of the agent owner. As the private key of the mobile agent is likely to be exposed, we introduce a new generic key-insulated proxy signature scheme. The scheme minimizes the damage caused by the secret key exposure. Furthermore, compared with all the previous works, the proposed scheme has 3 virtues: (1) the size of the proxy signature is constant, and independent of the number of in- sulated time period; (2) the size of the proxy secret key is constant q bits, without any additional overheads on the key length; (3) the scheme only has additional O(N ) hash com- putation overheads. Finally, we support our scheme with detailed security and performance analysis.