Secure Vickrey Auctions for Online Advertising
summary
Obsidian implements a maliciously secure Vickrey auction using a new reverse unary encoding for bids, verifiable function secret sharing to push validation offline, and lightweight ring signatures for anonymous bidder verification. It yields constant-round MPC-compatible protocols, keeps only winner identity and second-price revealed, and reports sub-second auction latency with communication under 1 MB for 100 bidders (domain 1,000). Evaluation shows ~15% faster than the closest tailored baseline and 4–10× throughput improvements over deployed exchanges while outperforming generic MPC/HE by orders of magnitude.
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chapters (14)
- 0:00Introduction
- 2:45Privacy risks in ad auctions
- 3:47Vickrey auctions for ads
- 4:49Secure Vickrey guarantees
- 6:15Browser-exchange split
- 7:38Secure auction challenges
- 8:21Reverse unary encoding
- 10:26Malformed bids handling
- 11:49FSS for bid validation
- 13:35FSS-based lookups
- 14:38New auction workflow
- 15:18Performance comparison
- 16:21Stress testing feasibility
- 16:42Conclusion
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