[Resource Topic] 2025/2118: Revisiting Rational Broadcast Protocols

Welcome to the resource topic for 2025/2118

Title:
Revisiting Rational Broadcast Protocols

Authors: Shunya Otomo, Kenji Yasunaga

Abstract:

A recent study by Yamashita and Yasunaga (GameSec 2023) presented a constant-round deterministic broadcast protocol secure against \emph{detection-averse} adversaries —
those who prefer to attack without being detected. In this work, we revisit their protocol and observe that it remains secure even against a broader class of adversaries, not necessarily detection-averse. We formalize its detection mechanism as \emph{local detectability} and construct broadcast protocols with local detectability that address two weaknesses of the original protocol: (1) it only guarantees weak validity, and (2) it may cause false detections.
Our first protocol achieves round complexity four against rational adversaries and t+4 against malicious adversaries, where the adversary corrupts at most t parties. Our second protocol achieves the optimal round complexity of t+1 for malicious adversaries, while the round complexity is four against detection-averse adversaries.

ePrint: https://eprint.iacr.org/2025/2118

See all topics related to this paper.

Feel free to post resources that are related to this paper below.

Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.

For more information, see the rules for Resource Topics .