Merkle Tree / Merkle Root
Cryptography● Common
A binary tree structure where each leaf node is a transaction hash, and each non-leaf node is a hash of its children. The root hash summarizes all transactions in a block, included in the block header. Enables efficient proof that a transaction is in a block without downloading all transactions.
Technical Notes
Leaf: double-SHA256(tx). Parent: double-SHA256(left || right). If odd number of leaves, last one is duplicated. SPV proof: transaction + path of sibling hashes to root. Proof size: O(log n) for n transactions. SegWit adds separate witness merkle root in coinbase.
Metadata
Visibility: Public
Created:1/3/2026by System