● New coinjoin mixing technique proposed: Max Hillebrand started a thread on the Bitcoin-Dev mailing list about Wormhole, a method developed during a Wasabi design discussion for sending payments as part of a chaumian coinjoin. The protocol prevents even the spender from learning the receiver’s Bitcoin address (within the limits of the anonymity set). Developer ZmnSCPxj notes that the technique is similar to tumblebit , which provides a trustless chaumian payment service. Hillebrand is requesting feedback on the design in the hopes of seeing it implemented in the future.

● Protocol specification for discreet log contracts (DLCs): DLCs are a contract protocol where two or more parties agree to exchange money dependent on the outcome of a certain event as determined by an oracle (or several oracles). After the event happens, the oracle publishes a commitment to the outcome of the event in the form of a digital signature, which the winning party can use to claim their funds. The oracle doesn’t need to know the terms of the contract (or even that there is a contract). The contract can look like either the onchain part of an LN transaction or it can be executed within an LN channel. This makes DLCs more private and efficient than other known oracle-based contract methods, and it’s arguably more secure as an oracle who commits to a false result generates clear evidence of their fraud.

This week Chris Stewart announced that several developers are working on a specification for using DLCs, with the goal of creating an interoperable design for use between different software, including LN implementations. See their repository for the current specification. Anyone interested in DLCs may also wish to review the scriptless scripts repository that documents other clever applications of digital signature schemes to contract protocols.