A Secure Scheme of Bidding and Tendering on Internet with Revocation of Bidder

This paper utilizes a group signature scheme to propose a secure scheme of bidding and tendering on Internet with revocation of bidder. This scheme realizes the anonymity of identity of bidders, unforgeability and public verifiability of successful bidders, etc. The paper resolves the problem of member deletion in group signatures. When a bidder is withdrawn, an authority only needs to modify a parameter of public key, and broadcasts it encrypted by the public key of another bidder. They needn’t to modify the digital certifications of other bidders, and can ensure the unlinkability of identity of the withdrawn bidders to the former items of tendering.