The property that once data is written to a blockchain, it cannot be altered or deleted. Immutability is enforced by cryptographic hash chaining—modifying any historical block changes its hash, breaking the chain. This provides tamper-proof audit trails. Note: smart contract state can be updated by authorized programs; immutability applies to the historical ledger.
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The property that once data is written to a blockchain, it cannot be altered or deleted. Immutability is enforced by cryptographic hash chaining—modifying any historical block changes its hash, breaking the chain. This provides tamper-proof audit trails. Note: smart contract state can be updated by authorized programs; immutability applies to the historical ledger.
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Immutability (immutability) Category: Blockchain General Definition: The property that once data is written to a blockchain, it cannot be altered or deleted. Immutability is enforced by cryptographic hash chaining—modifying any historical block changes its hash, breaking the chain. This provides tamper-proof audit trails. Note: smart contract state can be updated by authorized programs; immutability applies to the historical ledger. Related: Blockchain, Hash Function (Cryptographic)
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A distributed, append-only ledger that records transactions in cryptographically linked blocks. Each block contains a hash of the previous block, forming an immutable chain. Nodes in the network maintain copies of the ledger and reach agreement through consensus mechanisms. Blockchains enable trustless, decentralized record-keeping without a central authority.
A one-way mathematical function that maps arbitrary-length input to a fixed-size output (digest). Properties: deterministic, fast to compute, infeasible to reverse, collision-resistant. SHA-256 (used in Bitcoin, Solana PoH) produces 256-bit hashes. Keccak-256 is used in Ethereum. Hashes are used for block linking, Merkle trees, and data integrity.
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The ability of different blockchains to communicate and share data or assets. Achieved through bridges (Wormhole), messaging protocols (LayerZero, Axelar), and shared standards. Cross-chain interoperability enables multi-chain DeFi, unified liquidity, and chain-agnostic applications. Solana connects to other chains primarily through Wormhole and Circle's CCTP.
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A distributed, append-only ledger that records transactions in cryptographically linked blocks. Each block contains a hash of the previous block, forming an immutable chain. Nodes in the network maintain copies of the ledger and reach agreement through consensus mechanisms. Blockchains enable trustless, decentralized record-keeping without a central authority.
A one-way mathematical function that maps arbitrary-length input to a fixed-size output (digest). Properties: deterministic, fast to compute, infeasible to reverse, collision-resistant. SHA-256 (used in Bitcoin, Solana PoH) produces 256-bit hashes. Keccak-256 is used in Ethereum. Hashes are used for block linking, Merkle trees, and data integrity.
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A distributed, append-only ledger that records transactions in cryptographically linked blocks. Each block contains a hash of the previous block, forming an immutable chain. Nodes in the network maintain copies of the ledger and reach agreement through consensus mechanisms. Blockchains enable trustless, decentralized record-keeping without a central authority.
The protocol by which nodes in a distributed network agree on the current state of the ledger. Common mechanisms include Proof of Work (Bitcoin), Proof of Stake (Ethereum, Solana), and BFT variants. Consensus ensures all honest nodes converge on the same transaction history despite potential network delays or malicious actors.
A consensus mechanism where validators are selected to produce blocks based on the amount of cryptocurrency they have staked (locked) as collateral. PoS is energy-efficient compared to Proof of Work. Misbehaving validators risk losing their stake (slashing). Solana, Ethereum (post-Merge), Cosmos, and Cardano use PoS variants.
A consensus mechanism where miners compete to solve computationally expensive puzzles to produce blocks and earn rewards. PoW provides strong security (51% attack resistance) but is energy-intensive. Bitcoin and pre-Merge Ethereum use PoW. The difficulty adjusts to maintain target block times regardless of total network hash power.