Anonymous M+1-st price auction using ring signature

The M+1-st price auction is a style of auction in which the highest M bidders win and pay a uniform price, determined by the M+1-st price. This paper proposes an anonymous M+1-st price auction scheme based on ring signature and homomorphic encryption. It offers the security of bidding price and public verifiability. Meanwhile, both the anonymity of normal bidders and the non-repudiation of malicious bidders are achieved in the scheme.