Crash Fault vs Byzantine Fault
Programming Fundamentals · Bottom
Two failure models in distributed systems. Crash faults assume nodes either work correctly or stop entirely (fail-stop). Byzantine faults assume nodes can behave arbitrarily — sending conflicting messages, lying, or acting maliciously. Blockchains must tolerate Byzantine faults, requiring BFT consensus (like Solana's Tower BFT) that works even with up to 1/3 malicious validators.