We propose an efficient and secure sealed-bid auction protocol with two servers, a third party A and a seller S. A server A is not a trusted third party, but is assumed not to collude with a server S. Barring collusion between A and S, neither party gains any information about the bids, and moreover, the outcome of the auction will be correct. Moreover, the proposed auction protocol has a very small computational complexity and a similar communication overhead compared with Naor et al.’s scheme. Especially since a computation and communication overhead of a bidder are very efficient than Naor et al.’s scheme, the proposed scheme is more suitable to lightweight devices such as PDA, mobile phone, etc.