MerklePatriciapuut

MerklePatriciapuut is the term used for Merkle Patricia trees, a family of authenticated data structures that blend Merkle trees with a Patricia trie to provide a compact, tamper-evident key-value store with efficient proofs of membership and non-membership. In English-language sources the standard term is Merkle Patricia Trie (MPT); MerklePatriciapuut appears in some non-English renderings or as a localized name.

Its structure consists of a trie-like tree where nodes can be extension, leaf, or branch nodes. Each node stores hashed representations of its children, and the root hash acts as a cryptographic commitment to the entire dataset. The trie typically uses a compact encoding, and updates produce a new root hash while sharing structure with previous versions, enabling versioning and historical proofs.

Merkle Patricia trees are widely used in blockchain systems to store state in a way that enables light clients to verify data with small proofs. In Ethereum, for example, the global state, accounts, and storage are represented in state and storage tries, and the root hash is included in blocks to ensure integrity.

Advantages include compact proofs, deterministic lookup times, and efficient synchronization between peers. Limitations include the complexity of implementation, potential storage overhead for large datasets, and reliance on cryptographic hash functions. Variants exist that optimize for different use cases or programming languages, reflecting the diverse requirements of secure, distributed ledgers and databases.