Universe Detectors for Sybil Defense in Ad Hoc Wireless Networks

TL;DR

This paper introduces universe detectors to help wireless nodes distinguish real nodes from fictitious ones created by Sybil attacks, addressing a critical challenge in ad hoc wireless network security.

Contribution

It defines neighborhood discovery problems under Sybil attack, proposes universe detectors, and presents SAND algorithm demonstrating their effectiveness under certain topological constraints.

Findings

Universe detectors are necessary for Sybil defense in wireless networks.

SAND algorithm effectively solves neighborhood discovery with universe detectors.

Proposed detectors are proven to be the weakest necessary for the problems.

Abstract

The Sybil attack in unknown port networks such as wireless is not considered tractable. A wireless node is not capable of independently differentiating the universe of real nodes from the universe of arbitrary non-existent fictitious nodes created by the attacker. Similar to failure detectors, we propose to use universe detectors to help nodes determine which universe is real. In this paper, we (i) define several variants of the neighborhood discovery problem under Sybil attack (ii) propose a set of matching universe detectors (iii) demonstrate the necessity of additional topological constraints for the problems to be solvable: node density and communication range; (iv) present SAND -- an algorithm that solves these problems with the help of appropriate universe detectors, this solution demonstrates that the proposed universe detectors are the weakest detectors possible for each problem.