2013 12th IEEE International Conference on Trust, Security and Privacy in Computing and Communications (2013)
Melbourne, VIC Australia
July 16, 2013 to July 18, 2013
Minghui Zheng , Dept. of Comput. Sci., Hubei Univ. for Nat., Enshi, China
Yongquan Cui , Sch. of Comput. Sci. & Technol., Huazhong Univ. of Sci. & Technol., Wuhan, China
Liang Chen , Sch. of Comput. Sci. & Technol., Huazhong Univ. of Sci. & Technol., Wuhan, China
A (t, n)-threshold proxy signature scheme allows an original signer to delegate the signing capability to a group of n proxy members in such a way that any t or more than t proxy signers can generate a valid signature on behalf of the original signer. Recently, Ting et al.  proposed the first threshold proxy signature scheme from Paillier cryptosystem, and claimed that their construction is existentially unforgeable against chosen-message attacks and chosen-warrant attacks in the random oracle model. In this paper, however, we show that their scheme is insecure against a type II adversary who can access the secret key of the original signer, i.e., not only the proxy signers but also the original signer can generate a valid proxy signature. In addition, we analyze the causes of the attack and further discuss the possibility of avoiding the attack by improving the Ting et al.'s scheme.
Computer science, Public key, Educational institutions, Electronic mail, Privacy
Minghui Zheng, Yongquan Cui and Liang Chen, "Security Analysis of a Paillier-Based Threshold Proxy Signature Scheme," 2013 12th IEEE International Conference on Trust, Security and Privacy in Computing and Communications(TRUSTCOM), Melbourne, VIC Australia, 2014, pp. 683-687.