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Vol. 1 · Ed. 2026
CyberGlossary
Entry № 106

Blockchain Security

What is Blockchain Security?

Blockchain SecurityThe discipline of protecting distributed ledgers, their consensus mechanisms, smart contracts, and surrounding infrastructure from compromise, fraud, and theft.


Blockchain security covers the full stack of risks affecting public and permissioned ledgers: cryptographic primitives, consensus algorithms (Proof of Work, Proof of Stake), peer-to-peer networking, node operations, smart contract code, bridges, wallets, and the off-chain services and oracles that feed them. Attacks may target the protocol itself (51% attacks, long-range attacks), application logic (reentrancy, oracle manipulation), or users (wallet drainers, phishing). Because transactions are typically immutable and pseudonymous, recovery after a compromise is difficult, so security is enforced through code audits, formal verification, bug bounties, key management, and monitoring of on-chain activity.

Examples

  1. 01

    The Ronin Bridge hack (March 2022) drained roughly 625 million USD after attackers compromised validator keys.

  2. 02

    The Poly Network exploit (August 2021) saw about 611 million USD moved cross-chain via a contract authority bug.

Frequently asked questions

What is Blockchain Security?

The discipline of protecting distributed ledgers, their consensus mechanisms, smart contracts, and surrounding infrastructure from compromise, fraud, and theft. It belongs to the Web3 & Blockchain category of cybersecurity.

What does Blockchain Security mean?

The discipline of protecting distributed ledgers, their consensus mechanisms, smart contracts, and surrounding infrastructure from compromise, fraud, and theft.

How does Blockchain Security work?

Blockchain security covers the full stack of risks affecting public and permissioned ledgers: cryptographic primitives, consensus algorithms (Proof of Work, Proof of Stake), peer-to-peer networking, node operations, smart contract code, bridges, wallets, and the off-chain services and oracles that feed them. Attacks may target the protocol itself (51% attacks, long-range attacks), application logic (reentrancy, oracle manipulation), or users (wallet drainers, phishing). Because transactions are typically immutable and pseudonymous, recovery after a compromise is difficult, so security is enforced through code audits, formal verification, bug bounties, key management, and monitoring of on-chain activity.

How do you defend against Blockchain Security?

Defences for Blockchain Security typically combine technical controls and operational practices, as detailed in the full definition above.

What are other names for Blockchain Security?

Common alternative names include: Web3 security, DLT security.

Related terms

See also