Patent ID: 7181405

Claim:
An electronic tender system for accepting as a contract price the highest or lowest price among bids, comprising: a bidder sub-system including: a predefined set of code parameters in which a different code parameter is associated with each of respective bid amounts within a tenderable range, a code parameter acquisition section for acquiring a code parameter from said predefined set of code parameters corresponding to a bid amount selected by the bidder sub-system within a tenderable range, a code processing section for encoding the bid selected by the bidder sub-system using the acquired code parameter obtained by said code parameter acquisition section, and a transmission section for sending a message including an encoded bid encoded by said coding section to a tender opening sub-system, and a tender opening sub-system including: a reception section for receiving messages from bidder sub-systems including encoded bids until a closing time, a predefined set of decode parameters in which a different decode parameter is associated with each of respective contract price candidates, a candidate price selection section for sequentially selecting contract price candidates beginning with one of a highest and a lowest within said tenderable range, a decode parameter acquisition section for acquiring from said predefined set of decode parameters a decode parameter corresponding to a contract price candidate selected by the selection section, and a determination section for decoding encoded bids using an acquired decode parameter corresponding to a contract price candidate selected by the selection section to determine whether a bid that is the same as the contract price candidate selected by the selection section exists among encoded bids received by the reception section.