Merkle Proof

A Merkle proof is a small piece of data that allows a user to prove that a specific transaction exists within a Merkle tree without needing to see all the transactions in that tree. It consists of the target transaction hash and the sibling hashes needed to reconstruct the Merkle root.

By hashing these values together in the correct order, the user can verify if the result matches the known Merkle root of the block. This process is highly efficient and is used extensively in decentralized applications and sidechains to verify state changes.

Merkle proofs are essential for scalability, as they enable protocols to offload data verification to smaller, more manageable units. They allow for secure interactions between different layers of a blockchain, such as Layer 1 and Layer 2, without requiring full data synchronization.