Provably secure certificate‐based key‐insulated signature scheme

SUMMARY Certificate‐based signature computation is often performed on insecure devices where the signature key is easy to be exposed. To reduce the influence of key exposure, we introduce key‐insulated mechanism into certificate‐based cryptography and formalize the notion and security model of the certificate‐based key‐insulated signature scheme. We then present a certificate‐based key‐insulated signature scheme, which is proven to be existentially unforgeable against adaptive chosen message attacks in the random oracle model. The proposed scheme has potential applications in trusted computing.