Communication-efficiency is of key importance when constructing robust services in limited bandwidth environments, such as sensor networks. We focus on communication-efficiency in the context of quorum systems, which are useful primitives for building reliable distributed systems. To this end, we exhibit a new probabilistic quorum construction in which every node transmits at most O(log 2 n) bits per quorum access, where n is the number of nodes in the system. Our implementation, in addition to

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... being communication efficient, is also robust in the face of communication failures. In particular, it guarantees consistency (with high probability) in the face of network partitions. To the best of our knowledge, no existing probabilistic quorum systems achieve polylogarithmic communication complexity and are resilient to network partitions.