Paper 2021/392

How Private Are Commonly-Used Voting Rules?

Ao Liu, Yun Lu, Lirong Xia, and Vassilis Zikas


Differential privacy has been widely applied to provide privacy guarantees by adding random noise to the function output. However, it inevitably fails in many high-stakes voting scenarios, where voting rules are required to be deterministic. In this work, we present the first framework for answering the question: ``How private are commonly-used voting rules?" Our answers are two-fold. First, we show that deterministic voting rules provide sufficient privacy in the sense of distributional differential privacy (DDP). We show that assuming the adversarial observer has uncertainty about individual votes, even publishing the histogram of votes achieves good DDP. Second, we introduce the notion of exact privacy to compare the privacy preserved in various commonly-studied voting rules, and obtain dichotomy theorems of exact DDP within a large subset of voting rules called generalized scoring rules.

Available format(s)
Publication info
Published elsewhere. Uncertainty in Artificial Intelligence (UAI) 2020
differential privacydistributional differential privacyvotingrank aggregationsocial choicegeneralized scoring rules
Contact author(s)
yunlu mail @ gmail com
2021-03-27: received
Short URL
Creative Commons Attribution


      author = {Ao Liu and Yun Lu and Lirong Xia and Vassilis Zikas},
      title = {How Private Are Commonly-Used Voting Rules?},
      howpublished = {Cryptology ePrint Archive, Paper 2021/392},
      year = {2021},
      note = {\url{}},
      url = {}
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