A New Designated Confirmer Signature Variant with Intended Recipient

Previous designated confirmer signature schemes were less e#cient because complex zero-knowledge proof employed in confirmation and disavowal protocol. In this paper, we propose a new e#cient signature scheme which is recipient-specific and confirmer-specific. The new scheme is transformed from ID-based chameleon signature and inherits its advantage in simplicity and e#ciency. The scheme's security relies on the underlying secure chameleon signature and public key encryption scheme. We also considers the case of confirmer as an adversary in security proof