A Multi-user Information Encryption System Based On Improved Confirmer Signature

Confirmer digital signature is presented on the basis of undeniable signature. It is a new kind of digital signature with special purpose. In this paper, an improved confirmer digital signature is presented according to the analysis of the traditional confirmer signature algorithm and the introduction of zero-knowledge proof. Then combining this improved algorithm with RSA public key algorithm, we design a multi-user information encryption system. In this system, sender just need sign the encrypted message which includes zero-knowledge information once. Server will deliver this encrypted message to any limited receivers safely. By using decryption algorithm and validation algorithm, receivers can get right message and verify the validity of the sender's identity. This system has the attribute of non-repudiation of the sender by using the improved confirmer signature. In the end, the system is implemented primarily.