The Mimblewimble protocol is a blockchain protocol created to improve privacy, fungibility, and scalability of blockchains. It was created on July 16, 2016 by someone using the pseudonym for the French name of Voldemort from Harry Potter "Tom Elvis Jedusor". Notable privacy cryptocurrency projects built using the Mimblewimble protocol include Beam and Grin.
The Mimblewimble protocol makes transactions private by the recipient of a transaction randomly selecting a range of blinding factors which are provided by the transaction sender. The selected blinding factor is used to verify ownership by the receiver and permits the sender to complete the transaction.
The Mimblewimble protocol also uses the cryptographic method called CoinJoin which allows multiple transaction senders to combine their transactions into one transaction. This obscures the intended recipients to any observing third party by making a block of the Mimblewimble protocol consist of a list of all inputs, outputs, and signature data.