| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent an advantageous bidding wherein information is obtained in advance by determining a maximum or minimum bid price as a successful bid price according to bid indexes that a bidding starting device receives without letting all bidding devices know failed bid prices. SOLUTION: It is checked whether or not there is a bit price Ii as an upper- limit value (n) and when not, the bid price IRi having the value obtained by subtracting a unit value 1 from (n) is checked; when there is not the price, the value obtained by further subtracting the unit value 1 is checked and it is checked whether or not the bit price IRi with less values in order. Consequently, the largest bit price IRi can be searched for. Further, respective bidding devices 11i make hf(n+1)(IVi) open to the public in advance and when the bidding start device 12 makes hf(k)(IVi) open to the public in addition to bid prices k and IDi, a process by a unidirectional function (h) is performed for the hf(k)(IVi) as many times as f(n+1)-f(k); when the value h(n+1)-f(k)hf(k)(IVi) matches the hf(n+2)(IVi) which is made open, it can be considered that the bidding start process has correctly been performed.</p> |
