TumbleBit is a anonymous payments protocol from 2016 that is fully compatible with today’s Bitcoin protocol. TumbleBit allows parties to make payments through an untrusted Tumbler. No-one, not even the Tumbler, can tell which payer paid which payee during a TumbleBit epoch. TumbleBit consists of two interleaved fair-exchange protocols that prevent theft of bitcoins by cheating users or a malicious Tumbler. TumbleBit combines fast cryptographic computations (performed off the blockchain) with standard bitcoin scripting functionalities (on the blockchain) that realize smart contracts.
Note that A2L is faster and uses less bandwidth than TumbleBit.
- https://eprint.iacr.org/2016/575 - The paper
- https://github.com/BUSEC/TumbleBit - Implementation
- https://www.youtube.com/watch?v=8BLWUUPfh2Q&t=3787 - Talk at ScalingBitcoin 2016
- https://diyhpl.us/wiki/transcripts/scalingbitcoin/milan/tumblebit/ - Transcript of talk