秘密競標協定是一種普遍且重要的競標型態，廣泛應用於採購／工程合約、金融商品等之競標活動。本論文提出兩種適用於不同範圍的匿名式秘密競標協定：第一高價秘密競標協定與第（M + 1）高價秘密競標協定。本論文所提出的競標協定允許投標者可匿名地多次參與競標活動，無須重新註冊。此外，本論文所提出的協定尚可滿足未得標價之私密性、不可偽造性、不可陷害性、公平性、無連結性、可追蹤性、可驗證性及不可否認性等安全需求。

　　　　　Sealed-bid auctions are common and important types that are widely used in auctioning purchase/construction contracts, financial goods, etc. In this paper, two anonymous sealed-bid auction protocols are proposed: (1) a first-price sealed-bid auction protocol and (2) an (M + 1)st-price sealed-bid auction protocol. The proposed protocols allow a registered bidder to participate in multiple auction rounds anonymously with a one-time registration. They also satisfy the following security requirements: secrecy of losing bids, unforgeability, non-framing, fairness, unlinkability, traceability, verifiability, and non-repudiation.