A Triple Unlocking Mechanism Model Against Forging Signature Attack Based on Multivariate Polynomial Public Key Cryptosystem

Since the original signature model did not account for the possible threat of the forging signature attack, the majority of existing multivariate polynomial public key based signature schemes are at risk of forging signatures by equivalent key attacks. In this research, an enhanced signature model, Triple Unlocking Mechanism (TUM), is provided to resist all the possibility that the signature generated by the equivalent keys. The additional public keys are generated in the sake of enhancing the security by verifying internal unit information in the scheme after three designed unlocking operations. As a result, the signature can only be generated by the user who has the real legal key and the threat of the key recovery attack can be eliminated. The security of TUM signature based on random oracle model is proved. Experimental results demonstrate that, using an MI system coupled with TUM as an example, the advantages of the enhanced signature model are more secure than the original one at the expense of taking a little more time for signing. Moreover, influences of different parameters in multivariate polynomial public key signatures are investigated. Based on the original state-of-art model, the presented model is generic construction and applicable for existing multivariate signature scheme's construction.