A radical restructuring of the Bitcoin protocol, proposed by Tom Elvis Jedusor in 2016 in order to massively improve privacy and scalability of the digital currency. It is named after a curse in Harry Potter, since it aims “to prevent the blockchain from talking about all user's information.”
Tom Elvis Jedusor is the pseudonym of Voldemort in the French translation of Harry Potter. The protocol was described in a document posted on the Bitcoin IRC channel, through TOR hidden services.
MimbleWimble extends the idea of confidential transactions and CoinJoin, which allows aggregation of transactions without requiring interactivity.
Blocks in Mimblewimble are composed of three lists: an input list, and output list, and an excesses list. The input list references the old outputs, and the output list contains confidential transaction outputs. The excesses list are lists of signatures and differences between outputs and inputs.
Mimblewimble does not support the use of Bitcoin scripting language, which makes it incompatible with the existing Bitcoin protocol.