Robustness of the Tangle 2.0 Consensus

TL;DR

This paper evaluates the robustness of the Tangle 2.0 consensus protocol against Byzantine attacks, demonstrating its resilience up to 33% adversarial voting weight and confirming the necessity of the common coin mechanism for security.

Contribution

It provides an agent-based simulation analysis of Tangle 2.0's robustness, highlighting the importance of the common coin and confirming fast confirmation times in typical scenarios.

Findings

Robust against bait-and-switch attack up to 33% adversarial weight

Common coin mechanism is essential for robustness

Achieves around 1 second confirmation time

Abstract

In this paper, we investigate the performance of the Tangle 2.0 consensus protocol in a Byzantine environment. We use an agent-based simulation model that incorporates the main features of the Tangle 2.0 consensus protocol. Our experimental results demonstrate that the Tangle 2.0 protocol is robust to the bait-and-switch attack up to the theoretical upper bound of the adversary's 33% voting weight. We further show that the common coin mechanism in Tangle 2.0 is necessary for robustness against powerful adversaries. Moreover, the experimental results confirm that the protocol can achieve around 1s confirmation time in typical scenarios and that the confirmation times of non-conflicting transactions are not affected by the presence of conflicts.