Research Article
PP-VCA: A Privacy-Preserving and Verifiable Combinatorial Auction Mechanism
Algorithm 3
Privacy-preserving winner determination (PPWD).
| Input: CSP has a pair of ElGamal key: , ; the auctioneer AUCT has ; has and . | | Output: AUCT obtains the winner set and corresponding bundle set . | | 1: CSP: | | (a) Select a large number , calculate , and select s.t. | | (b) Randomly choose noise from | | (c) Send , and to | | 2: : | | (a) Compute the average value | | (b) Compute | | (c) Send to AUCT | | 3: AUCT and jointly perform: | | (a) AUCT picks the largest and records the corresponding bidder as . is the bundle of | | (b) On input (, , , ), perform privacy-preserving scalar product protocol (PPSP) to obtain | | (c) AUCT receives | | 4: AUCT: | | (a) If , is the winner. Inform to send , bundle and and put into the winner set and mark s bundle as auctioned in | | (b) Otherwise, remove from bidders | | Repeat Steps 3–4 until no set can be updated |
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