Combinatorial auctions have recently attracted the interest of many researchers due to their promising applications such as the spectrum auctions recently held by the FCC. In a combinatorial auction, multiple items with interdependent values are sold simultaneously and bidders are allowed to bid on any combination of items. The Generalized Vickrey Auction (GVA) can handle combinatorial auctions and has several good theoretical characteristics. However, GVA has not yet widely used in practice due to its vulnerability to fraud by the auctioneers. In this paper, to prevent such fraud, we propose a secure Generalized Vickrey Auction scheme where the result of the auction can be computed while the actual evaluation values of each bidder are kept secret.