The Convertible Undeniable Multi-Signature Scheme

In the convertible undeniable multi-signature scheme, signers can convert undeniable multi-signature to the ordinary one. The authenticity of confidential document signed by undeniable multi-signature scheme can only be verified with co-operation of all signers. If the document is no longer confidential, it can be opened to public use by converting the undeniable multi-signature to the ordinary one. In this study, the efficient multipurpose convertible undeniable multi-signature scheme is proposed. The proposed scheme satisfies undeniable property and can be used to protect ownership of multimedia contents made by many authors.