Named after Ralph Merkle, who wrote a 1987 paper titled “A Digital Signature Based on a Conventional Encryption Function,” Merkle trees organise and verify data using a tree-like structure and are invaluable to distributed systems and peer-to-peer networks because they can verify data very efficiently. Merkle trees cut out extraneous work by exchanging compact hashes instead of entire files, minimizing network traffic.
In blockchain systems like Bitcoin, Merkle trees ensure transaction integrity, allowing participants to verify entire blocks through the Merkle root – a single hash that serves as a concise representation of the entire set of data and sits at the top of the tree. Another example of Merkle trees in action is Celestia’s Namespaced Merkle trees (NMTs). Celestia utilises NMTs modified hash function alongside data availability sampling to partition block data into distinct namespaces for applications, ensuring each application only downloads its relevant data.