---
title: "Byzantine Fault Tolerance"
path: "/contents/tech/core-concepts/byzantine-fault-tolerance"
version: "1.2.0"
author: "Hydrate"
createdAt: "2026-02-18T22:38:09.775Z"
updatedAt: "2026-03-16T18:20:56.733Z"
---

# Byzantine Fault Tolerance

<Infobox>
| **Concept** | Consensus in adversarial environments |
| **Threshold** | Tolerates up to ⅓ faulty nodes |
| **Radix Implementation** | [Cerberus](/contents/tech/core-protocols/cerberus-consensus-protocol) |
</Infobox>

## Overview

**Byzantine Fault Tolerance ([BFT](https://en.wikipedia.org/wiki/Byzantine_fault))** is the property of a distributed system that enables it to reach consensus even when up to one-third of participating nodes are malicious, unresponsive, or sending conflicting information. The name comes from the Byzantine Generals Problem — a thought experiment about coordinating military strategy when some generals may be traitors.

All secure blockchain consensus protocols must be BFT. Radix's [Cerberus](/contents/tech/core-protocols/cerberus-consensus-protocol) is a BFT protocol that uniquely braids consensus across shards, achieving both fault tolerance and [atomic composability](/contents/tech/core-concepts/atomic-composability) in a sharded environment.