MimbleWimble

Mimblewimble is a blockchain protocol designed to enable private and scalable cryptocurrencies. It was described in a 2016 white paper by an anonymous author using the pseudonym Tom Elvis Jedwards, and the name borrows a term from the Harry Potter series. The design aims to reduce blockchain size and provide strong privacy by default through a streamlined transaction model.

Core design features include a refined version of the UTXO model where transaction amounts are hidden using Pedersen commitments. Range proofs are used to verify that concealed amounts are non-negative without revealing them. The protocol uses scriptless scripting instead of a traditional smart contract language, and each transaction includes a kernel that proves the spend is authorized and that fees are accounted for. A key architectural idea is cut-through: when a transaction’s inputs and outputs can be combined within a block or set of blocks, the spent outputs can be removed from the chain, shrinking the on-chain data.

Privacy and anonymity are central to Mimblewimble. By hiding amounts and reducing traceable linkage between inputs and outputs, the chain presents a smaller, harder-to-analyze transcript of transactions. Traditional addresses are largely replaced by ephemeral keys, and the overall design minimizes data that must be stored and transmitted.

Adoption and implementations have included several notable projects, with Grin and Beam among the most prominent efforts to implement the protocol in practice. The approach is the subject of ongoing research and development, balancing privacy, usability, and auditability.