Merkle Tree
A Merkle tree is a structure that folds thousands of hashes into a single root hash. Each transaction hashes, pairs of hashes hash again, and so on upward.
A Merkle tree is a structure that folds thousands of hashes into a single root hash. Each transaction hashes, pairs of hashes hash again, and so on upward. To prove a transaction is inside a block, you only need log₂(n) of those hashes — not the whole block.
Why it matters
Merkle trees are why light wallets work: a phone can verify “this transaction is in this block” by checking a handful of hashes instead of downloading the entire blockchain. Every major chain uses them; they’re the quiet performance miracle under the hood.
Related terms
hash · block ·
blockchain