Enhancing e-commerce security through computing technology alone is not sufficient. E-commerce designers should apply economic mechanisms to design proper digital processes that accommodate new perspectives raised in e-commerce. For instance, traditional auction mechanisms, such as the Generalized Vickrey Auction, are vulnerable to false-name bidding, an online fraud exploiting the lack of authentication over the Internet. We develop a Sealed-bid Multi-round Auction Protocol (S-MAP), which sells multi-unit identical goods. S- MAP is not only robust against false-name bidding but also simple and efficient.