Counteracting Byzantine Adversaries with Network Coding: An Overhead Analysis

TL;DR

This paper analyzes the transmission overhead of different Byzantine detection schemes in network coding, showing how their efficiency varies with attack probability and proposing tradeoffs between overhead and detection effectiveness.

Contribution

It compares three Byzantine detection schemes in network coding, providing a detailed overhead analysis and tradeoff characterization based on attack probability.

Findings

Packet-based detection is most bandwidth-efficient at high attack probabilities.

Generation-based detection reduces overhead when attack probability is low.

Tradeoff between generation size and detection overhead is characterized.

Abstract

Network coding increases throughput and is robust against failures and erasures. However, since it allows mixing of information within the network, a single corrupted packet generated by a Byzantine attacker can easily contaminate the information to multiple destinations. In this paper, we study the transmission overhead associated with three different schemes for detecting Byzantine adversaries at a node using network coding: end-to-end error correction, packet-based Byzantine detection scheme, and generation-based Byzantine detection scheme. In end-to-end error correction, it is known that we can correct up to the min-cut between the source and destinations. However, if we use Byzantine detection schemes, we can detect polluted data, drop them, and therefore, only transmit valid data. For the dropped data, the destinations perform erasure correction, which is computationally lighter than error correction. We show that, with enough attackers present in the network, Byzantine detection schemes may improve the throughput of the network since we choose to forward only reliable information. When the probability of attack is high, a packet-based detection scheme is the most bandwidth efficient; however, when the probability of attack is low, the overhead involved with signing each packet becomes costly, and the generation-based scheme may be preferred. Finally, we characterize the tradeoff between generation size and overhead of detection in bits as the probability of attack increases in the network.