The biometric based convertible undeniable multi-signature scheme to ensure multi-author copyrights and profits

Digital content is easy to reproduce and manipulate. It is difficult to distinguish the original content from pirated copies. A cryptographic method is needed to protect content author's ownership and secure content distribution. The method should be extended to the case of multiple authors since the content is completed with the assistance of many authors. In this paper, the biometric-based, convertible, and undeniable multi-signature scheme is proposed. The private and public keys are generated using a signer's biometric data and a random secret value. Thus, lending the private key to the proxy signer is not possible. All the signers should participate in multi-signature generation and verification stages. The proposed scheme also provides a signature conversion process in which undeniable multi-signature is converted to the ordinary one. We demonstrate how our scheme is useful to ensure multi-author copyrights and profits.