Forward-Secure Identity-Based Signature: New Generic Constructions and Their Applications
As modern cryptographic schemes rely their security on the secrecy of the private keys used in them, exposing such keys results in a total loss of security. In fact, attackers have been developing various techniques to seize the secret keys rather than to cryptanalyze the underlying cryptographic primitives. Digital signature schemes, which are widely employed in many applications, are not an exception to the key exposure problem. A number of solutions for protecting signature schemes from key exposure have been proposed, and one of them is a forward-secure signature. Informally, forward-secure signature schemes can guarantee the unforgeability of the past signatures, even if the current secret signing key is exposed.