【原著論文】Proof of Team Sprint（PoTS）の耐攻撃性: シミュレーションによる分析

Abstract

This study evaluates the robustness of Proof of Team Sprint (PoTS) against adversarial attacks through simulations, focusing on both the attacker win rate and computational efficiency under varying team sizes (N) and attacker ratios (α). PoTS is a recently proposed consensus mechanism that relies on randomly formed teams of participants to collaboratively generate blocks. Unlike traditional consensus methods where individual nodes compete independently, PoTS distributes responsibility across multiple nodes in a team, thereby increasing resilience against coordinated attacks. Our simulation results demonstrate that PoTS effectively reduces an attacker’s ability to dominate the consensus process, even under challenging conditions. For instance, when α ＝ 0.5, the attacker win rate decreases from 50.7% at N ＝ 1 to below 0.4% at N ＝ 8, effectively neutralizing adversarial influence. Similarly, at α ＝ 0.8, the attacker win rate drops from 80.47% at N ＝ 1 to only 2.79% at N ＝ 16, highlighting PoTS’s robustness under extreme threat levels. In addition to its strong security properties, PoTS maintains high computational efficiency by synchronizing block generation within each team. We introduce the concept of Normalized Computation Efficiency (NCE) to quantify this efficiency gain, demonstrating that PoTS significantly improves resource utilization as team size increases. As N grows, PoTS not only enhances security but also achieves better computational efficiency due to the averaging effects of execution time variations among team members. These findings underscore PoTS as a promising and practical alternative to traditional consensus mechanisms, such as Proof of Work (PoW) and Proof of Stake (PoS). By leveraging team-based block generation, sequential execution, and randomized participant reassignment in each round, PoTS provides a scalable, resilient, and energy-efficient framework for decentralized consensus in blockchain systems.