No, I haven’t gone crazy. Named after a Harry Potter spell rendering the target incapable of speaking coherently, mimblewimble is a blockchain protocol which scrambles up the transaction quantities and addresses, giving both a high degree of privacy and an efficient representation allowing massive savings on block space. According to its anonymous inventor, “I call my creation Mimblewimble because it is used to prevent the blockchain from talking about all user’s information”. Remarkable properties include not just hiding transaction quantities, but also allowing all transactions to be merged into a single big transaction, and spent outputs combined with their corresponding inputs and stripped from the blockchain. This last point has potential huge savings on blockchain space and validation time.
The protocol was implemented by the Grin and Beam cryptocurrencies, launched in January 2019. More recently, it was introduced into Litecoin in the MWEB upgrade (Mimblewimble extension block). This formally locked in on 3 May 2022 and went live a couple of weeks later.