Advances in Cryptology – CRYPTO 2005

Volume 3621 of the series Lecture Notes in Computer Science pp 241-257

Privacy-Preserving Set Operations

  • Lea KissnerAffiliated withCarnegie Mellon University
  • , Dawn SongAffiliated withCarnegie Mellon University


In many important applications, a collection of mutually distrustful parties must perform private computation over multisets. Each party’s input to the function is his private input multiset. In order to protect these private sets, the players perform privacy-preserving computation; that is, no party learns more information about other parties’ private input sets than what can be deduced from the result. In this paper, we propose efficient techniques for privacy-preserving operations on multisets. By building a framework of multiset operations, employing the mathematical properties of polynomials, we design efficient, secure, and composable methods to enable privacy-preserving computation of the union, intersection, and element reduction operations. We apply these techniques to a wide range of practical problems, achieving more efficient results than those of previous work.