Privately Computing Set-Union and Set-Intersection Cardinality via Bloom Filters

In this paper we propose a new approach to privately compute the set-union cardinality and the set-intersection cardinality among multiple honest-but-curious parties. Our approach is inspired by a proposal of Ashok and Mukkamala (DBSec’14) which deploys Bloom filters to approximate the size tightly. One advantage of their solution is that it avoids ample public-key cryptography. Unfortunately, we show here that their protocol is vulnerable to actual attacks. We therefore propose a new Bloom filter based protocol, also forgoing heavy cryptography, and prove its security.

• Type: Journal
• Year: 2015
• Where: ACISP
• Authors: Rolf Egert, Marc Fischlin, David Gens, Sven Jacob, Matthias Senker, Jörn Tillmanns
• Keywords: ACISP 2015, Security Privacy