Definition
A Merkle proof is a cryptographic inclusion or non-inclusion witness derived from a Merkle Tree that demonstrates that a specific data element corresponds to a committed root hash. It consists of the minimal set of sibling hashes and positional information required for a verifier to recompute the Merkle root and validate membership (or absence) of the element without accessing the full underlying dataset.
In Simple Terms
A Merkle proof is a compact cryptographic record that shows a piece of data really belongs to a larger data set represented by a single hash at the top of a Merkle Tree. By checking only a few hashes from the tree, a verifier can confirm the data’s presence or absence without seeing all other data.
Context and Usage
Merkle proofs appear in blockchain protocols, light client designs, and data-availability schemes whenever efficient verification of membership in a large authenticated data structure is required. They are used as fundamental system components in commitment schemes that rely on Merkle Trees as their underlying accumulator structure, enabling verifiers to check data consistency and integrity using only a small, logarithmic-sized witness relative to the total number of elements.