Merkle Patricia Trie
A hybrid data structure in Ethereum combining Merkle trees and Patricia tries for efficient state storage.
The Merkle Patricia Trie combines a Merkle [Tree](/en/terms/merkle-tree) (for cryptographic verification of data integrity) and a Patricia Trie (for efficient key-value lookups). It allows Ethereum to store the global state (account balances, smart contract code, and storage) in a way that is both tamper-proof and quick to access. Every block header contains the root hash of the state trie, allowing any node to verify the entire state without storing the full history.
graph LR
Center["Merkle Patricia Trie"]:::main
Rel_ethereum["ethereum"]:::related -.-> Center
click Rel_ethereum "/terms/ethereum"
Rel_merkle_tree["merkle-tree"]:::related -.-> Center
click Rel_merkle_tree "/terms/merkle-tree"
Rel_data_structure["data-structure"]:::related -.-> Center
click Rel_data_structure "/terms/data-structure"
classDef main fill:#7c3aed,stroke:#8b5cf6,stroke-width:2px,color:white,font-weight:bold,rx:5,ry:5;
classDef pre fill:#0f172a,stroke:#3b82f6,color:#94a3b8,rx:5,ry:5;
classDef child fill:#0f172a,stroke:#10b981,color:#94a3b8,rx:5,ry:5;
classDef related fill:#0f172a,stroke:#8b5cf6,stroke-dasharray: 5 5,color:#94a3b8,rx:5,ry:5;
linkStyle default stroke:#4b5563,stroke-width:2px;
🧒 Explain Like I'm 5
Generated ELI5 content
🤓 Expert Deep Dive
Generated expert content
❓ Frequently Asked Questions
Why does Ethereum use this instead of a regular Merkle Tree?
Because Ethereum's state changes constantly, and a Patricia Trie is more efficient for updating and looking up specific keys.
Is this different from a Merkle Tree?
Yes, it's a hybrid. It adds the 'path' compression of Patricia Tries to standard Merkle Trees.
Where is it stored?
It is stored in Ethereum's LevelDB database, with the root hash included in every block header.