Secure Auctions without an Auctioneer via Verifiable Secret Sharing.

ABSTRACTCombinatorial auctions are a research hot spot. They impact people's daily lives in many applications such as spectrum auctions held by the FCC. In such auctions, bidders may want to submit bids for combinations of goods. The challenge is how to protect the privacy of bidding prices and ensure data security in these auctions? To tackle this challenge, we present an approach based on verifiable secret sharing. The approach is to represent the price in the degree of a polynomial; thus the maximum/sum of the degree of two polynomials can be obtained by the degree of the sum/product of the two polynomials based on secret sharing. This protocol hides the information of bidders (bidding price) from the auction servers. The auctioneers can obtain their secret shares from bidders without a secure channel. Since it doesn't need a secure channel, this scheme is more practical and applicable to more scenarios. This scheme provides resistance to collusion attacks, conspiracy attacks, passive attacks and so on. Compared to [11, 12], our proposed scheme provides authentication without increasing the communication cost.