Implementing e-Auctions with Sharemind Md Sadek Ferdous 12

Implementing e-Auctions with Sharemind Md. Sadek Ferdous 12 th November 2008

Overview e-Auction Advantages of e-Auction steps Security considerations Design Issues Proposed Solution Auction Types of Auction Possible exploitations in Auction Conclusions Sharemind Proposed solution Design issues in the solution Suggestion Conclusions Implementing e-Auctions with Sharemind November 12, 200

Auction e-Auction Proposed Solution • Mention of auction in as early as 500 B. C • One of the main forms of selling, buying and exchanging goods • Objective is the efficient trading of commodities Conclusions Implementing e-Auctions with Sharemind November 12, 200

Types of auctions Auction e-Auction Proposed Solution Conclusions • Open cry auction --English and Dutch auction • Sealed bid auction --Sealed bid first price auction and Vickrey auction • Multi item auction --Discriminative auction, Non-discriminative --Combinatorial and Walrasian Auction • All pay auction • Buyout auction --Permanent & Temporary • No reserve (NR) auction • Reserve auction • Reverse auction • Round robin auction Implementing e-Auctions with Sharemind November 12, 200

Exploitations in auctions Auction e-Auction Proposed Solution • • • Bid shielding Collusion Bid schilling Bid sniping Bid siphoning Mispresented or non-existent item Conclusions Implementing e-Auctions with Sharemind November 12, 200

e-Auction Proposed Solution • Shorthand for Electronic auction • One of the major sources of revenue for e. Commerce • e. Bay with yearly revenue of 7. 67 Billion USD is the main actor to popularize the term e-Auction Conclusions Implementing e-Auctions with Sharemind November 12, 200

Advantages Auction e-Auction • No time constraint • No geographical constraint Proposed Solution • Potentially large number of sellers and buyers Conclusions Implementing e-Auctions with Sharemind November 12, 200

Challenges Auction Dependable & Security • Conclusions Posting • Proposed Solution Fraudulancy • Implementing e-Auctions with Sharemind Mode of payment • e-Auction • Guarding against problems of traditional auctions November 12, 200

Auction steps Auction e-Auction • Initialization • Registration Proposed Solution • Bidding • Winner determination Conclusions Implementing e-Auctions with Sharemind November 12, 200

Security considerations Auction • Unforgeability e-Auction • Non-repudiation • Anonymity Proposed Solution • Public verfiability • Robustness • Efficiency Conclusions • Fairness Implementing e-Auctions with Sharemind November 12, 200

Design Issues Auction e-Auction • Trust issues Proposed Solution • Anonymity issues • Bid authentication issue Conclusions Implementing e-Auctions with Sharemind November 12, 200

Sharemind Auction e-Auction • A framework for secure computation based on secret sharing. • In secret sharing, a secret value is divided among several values known as shares • Origianal secret can be reconstructed only if all the shares are known. Proposed Solution Conclusions • In Sharemind, there are miner nodes and controller node. • Controller divides the secret into share and sends them to the miners, miners perform operations on those shared values. • Currently add or multiply two shared values, multiply a shared value by a constant, extract bits from shared value, determine if the two shared values are equal and if not, which one is greater. Implementing e-Auctions with Sharemind November 12, 200

Proposed solution Auction e-Auction Proposed Solution Sharemind with Group Signature Scheme Auction type: Sealed bid Conclusions Implementing e-Auctions with Sharemind November 12, 200

List of parties Auction e-Auction Proposed Solution • • • Auctioneer Bidder Registrar Miners Controller Conclusions Implementing e-Auctions with Sharemind November 12, 200

Auction Steps Auction Initialization: e-Auction Proposed Solution • Auctioneer sets up an auction and advertises it to the public. • Registrar sets up the group certificate. Conclusions Implementing e-Auctions with Sharemind November 12, 200

Auction Steps Auction e-Auction • Bidder creates a pair of public and private key. • Sends a message to the auctioneer. • Auctioneer provides a token. Registration Proposed Solution Conclusions • Bidder sends this token and his public key to the registrar. • Registrar issues a group certificate and identifier for him. Implementing e-Auctions with Sharemind November 12, 200

Auction Steps Auction e-Auction Proposed Solution • Bid is sent to the controller. • Controller signs them using private key, and then divides into three share, signs them again using group certificate and sends them to the miners. • The signature with private key adds veriability & group signature adds anonymity. Bidding • Miners verify the bid using group public key and stores them in their local databases. Conclusions • When bid ends, the miners determine the highest bid & send that bid and the signature to the auctioneer. Implementing e-Auctions with Sharemind November 12, 200

Auction Steps Auction e-Auction • The auctioneer publishes the winning bid. • The winning bidder contacts with his identifier and signature Winner determination Proposed Solution • The auctioneer contacts the registrar to get back the public key and the token associated with that id and receives them. • The auctioneer comapres the two signatures, if it matches, the winner’s id is published. Conclusions • If more than one winner found, a second phase of auction may take place. Implementing e-Auctions with Sharemind November 12, 200

Design issues of the architecture Auction e-Auction Proposed Solution • Trust issues • Anonymity issue • Bid authentication issue Conclusions Implementing e-Auctions with Sharemind November 12, 200

Enhancements of Sharemind Auction e-Auction Proposed Solution • Multiple controllers • Simultanenous connections • Hybrid database Conclusions Implementing e-Auctions with Sharemind November 12, 200

Conclusions Auction This talk has: e-Auction Proposed Solution Conclusions • described various types of auction and different exploitation methods in auction, • provided an overview on advantages, security considerations and design issues in e-Auction, • presented a novel approach on how to integrate Sharemind for e-Auction using group signature scheme, and • suggested a few enhancements based on the proposal. Implementing e-Auctions with Sharemind November 12, 200

Auction e-Auction Proposed Solution Thank you. Questions or comments? Conclusions Implementing e-Auctions with Sharemind November 12, 200