Byzantine Fault Tolerance

Definition ∞ Byzantine Fault Tolerance is a property of a distributed system that allows it to continue operating correctly even when some of its components fail or act maliciously. In blockchain contexts, it ensures that the network can reach agreement on the state of the ledger despite the presence of nodes that may exhibit unpredictable or adversarial behavior. This capability is fundamental to the security and reliability of decentralized ledgers.
Context ∞ Debates concerning Byzantine Fault Tolerance often arise when discussing the security models of various blockchain protocols, particularly in relation to their resistance against Sybil attacks or coordinated malicious actions by network participants. Its implementation and robustness are critical considerations for assessing the trustworthiness of a given distributed ledger technology.

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→Proof Reuse

→Software Design

→Distributed Ledger

Composable Formal Verification Secures DAG Consensus Protocols Efficiently

A new compositional framework enables proof reuse across diverse DAG protocols, practically halving the effort for provable, architectural security.

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→Directed Acyclic Graph

→Network Synchrony

→Low Latency Applications

Uncertified DAG Consensus Achieves Optimal Three-Round Finality and Sub-Second Latency

The Mysticeti protocol uses uncertified DAG blocks and a novel commit rule to reach the theoretical three-round latency limit, unlocking true sub-second finality for high-throughput chains.

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→Agent Skepticism

→Network Topology

→Consensus Security

LLM Agents Shatter Classical BFT Bound via Confidence-Weighted Consensus

Confidence Probing-based Weighted BFT leverages LLM agents' inherent skepticism to exceed the classical $f < n/3$ fault tolerance limit, fundamentally enhancing consensus security.

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→Cryptographic Randomness

→Probabilistic Safety

→State Machine Replication

Random Asynchronous Model Overcomes FLP Impossibility for Consensus Security

Redefining the asynchronous network model with non-adversarial scheduling circumvents the classic FLP impossibility, enabling provably live BFT consensus.

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→Mechanism Design

→Byzantine Fault Tolerance

→Economic Security

Mechanism Design Enforces Truthful Consensus Equilibrium in Proof-of-Stake

A game-theoretic revelation mechanism creates a unique, subgame perfect equilibrium for validating nodes to propose truthful blocks, structurally mitigating dishonest forking risks.

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→State Machine Replication

→Transaction Finality Quorum

→BFT Consensus

Decoupled Quorums Accelerate BFT Consensus and Transaction Finality

Minimmit, a new BFT protocol, separates the small quorum for view progression from the finality quorum, accelerating distributed systems.

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→Parallel Consensus

→BFT Performance

→Linear Communication

Leaderless Asynchronous Consensus Achieves Optimal Complexity and Two-Round Finality

This leaderless BFT protocol, using a novel $O(n)$ threshold signature, achieves optimal resilience, linear communication, and two-round finality.

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→Protocol Efficiency

→Byzantine Fault Tolerance

→Cross-Cluster Communication

Cross-Cluster Consistent Broadcast Enables Efficient Replicated State Machine Interoperability

The new Cross-Cluster Consistent Broadcast (C3B) primitive and PICSOU protocol solve inter-RSM communication, achieving 24x better performance for decentralized systems.

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→Proof-of-Stake

→External Adversary Model

→Cryptoeconomic Security

External Adversary Model Secures Sleepy Proof-of-Stake Consensus

This work defines the external adversary model, proving sleepy Proof-of-Stake can securely withstand fully fluctuating node participation.

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→Threshold Quorums

→Transaction Dissemination

→Asynchronous Agreement

Asymmetric Trust DAG Consensus Achieves Constant-Round Asynchronous Agreement

This research introduces the first DAG-based consensus using asymmetric quorums, allowing nodes' subjective trust assumptions to secure high-performance asynchronous protocols.