A Key Encryption for Digital Signature by Forward Security

Abstract

In a cryptography there are certain insecure devices in which the threat of key exposure represents
a serious problems. In an effort the damage caused by exposure of secrete key stored on such devices. The
digital signature scheme in which the public key is fixed but the secret signing key is updated at regular
intervals so as to provide a forward security. The exposure of a secret key corresponding to a given time
period does not enable an adversary to “break” the scheme for any prior time period. This can be useful to
mitigate the damage caused by key exposure without requiring distribution of keys. We present the first
constructions of a (non-interactive) forward-secure public-key encryption scheme. Our main construction
achieves security against chosen plaintext attacks under the decisional bilinear Diffie Hellman assumption in
the standard model.