Identity-based key-insulated proxy signature

Abstract

In proxy signature schemes, the proxy signer B is permitted to produce a signature on behalf of the original signer A. However, exposure of proxy signing keys can be the most devastating attack on a proxy signature scheme since any adversary can sign messages on behalf of the proxy signer. In this paper, we applied Dodis, et al.’s key-insulation mechanism and proposed an Identity-Based (ID-based) Key-Insulated Proxy Signature (IBKIPS) scheme with secure key-updates. The proposed scheme is strong key-insulated and perfectly key-insulated. Our scheme also supports unbounded period numbers and random-access key-updates.