Chameleon hash is the main primitive to construct a chameleon signature scheme which provides nonrepudiation and non-transferability simultaneously. However, the initial chameleon hash schemes suffer from the key expo...Chameleon hash is the main primitive to construct a chameleon signature scheme which provides nonrepudiation and non-transferability simultaneously. However, the initial chameleon hash schemes suffer from the key exposure problem: non-transferability is based on an unsound assumption that the designated receiver is willing to abuse his private key regardless of its exposure. Recently, several key-exposure-free chameleon hashes have been constructed based on RSA assumption and SDH (strong Diffie-Hellman) assumption. In this paper, we propose a factoring-based chameleon hash scheme which is proven to enjoy all advantages of the previous schemes. In order to support it, we propose a variant Rabin signature scheme which is proven secure against a new type of attack in the random oracle model.展开更多
基金This work is partially supported by the National Natural Science Foundation of China under Grants No. 10271042 and No. 60373085.
文摘Chameleon hash is the main primitive to construct a chameleon signature scheme which provides nonrepudiation and non-transferability simultaneously. However, the initial chameleon hash schemes suffer from the key exposure problem: non-transferability is based on an unsound assumption that the designated receiver is willing to abuse his private key regardless of its exposure. Recently, several key-exposure-free chameleon hashes have been constructed based on RSA assumption and SDH (strong Diffie-Hellman) assumption. In this paper, we propose a factoring-based chameleon hash scheme which is proven to enjoy all advantages of the previous schemes. In order to support it, we propose a variant Rabin signature scheme which is proven secure against a new type of attack in the random oracle model.