Towards private and accountable online advertising

Speaker

Ke Zhong
University of Pennsylvania

Host

Alexandra Henzinger
CSAIL MIT
Abstract:
Existing online advertising systems are used by billions of users every day. The current systems can be improved with several interesting properties including privacy, accountability, and anti-fraud efforts. I am going to talk about our recent works on improving the ads systems. And specifically, I will present Addax, a fast, verifiable, and private online ad exchange. When a user visits an ad-supported site, Addax runs an auction similar to those of leading exchanges; Addax requests bids, selects the winner, collects payment, and displays the ad to the user. A key distinction is that bids in Addax’s auctions are kept private and the outcome of the auction is publicly verifiable. Addax achieves these properties by adding public verifiability to the affine aggregatable encodings in Prio (NSDI’17) and by building an auction protocol out of them. Our implementation of Addax over WAN with hundreds of bidders can run roughly half the auctions per second as a non-private and non-verifiable exchange, while delivering ads to users in under 600 ms with little additional bandwidth requirements. This efficiency makes Addax the first architecture capable of bringing transparency to this otherwise opaque ecosystem.