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Onchain Economics
Infrastructure

51% Attack

An attack where an entity gains majority control of a network's mining/validation power, enabling double-spending or censorship.

In-Depth Explanation

With 51% of hashpower (PoW) or stake (PoS), an attacker can reorganize the blockchain, reverse their own transactions (double-spend), or censor others. Larger networks are more secure because the cost of 51% is prohibitive. Smaller coins have suffered successful 51% attacks. Even 51% attackers can't steal others' funds or create coins from nothing.

Related Terms

Double-Spending

The potential flaw in digital currency systems where the same token is spent more than once.

Consensus Mechanism

The method by which a blockchain network agrees on the current state of the ledger and validates new transactions.

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Gas Fees

Transaction fees paid to validators/miners for executing operations on a blockchain.

Gwei

A denomination of Ether equal to one billionth of an ETH, commonly used to express gas prices.

Layer 2

L2

Scaling solutions built on top of a base blockchain (L1) that process transactions off-chain while inheriting L1 security.

Layer 1

L1

The base blockchain that provides security and consensus, such as Ethereum, Bitcoin, or Solana.

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