Artem Chystiakov’s Simplicity-based design shifts signer communication onto the blockchain and adds programmable spending rules, though he described it as early research rather than an official Blockstream initiative.
Blockstream Simplicity ecosystem engineer Artem Chystiakov has presented an experimental Bitcoin multisignature design that replaces the usual off-chain signer coordination with on-chain communication recorded through OP_RETURN. In an X post on Monday, he said the system lets participants interact through only the front end and the blockchain, avoiding messaging apps, email, coordination servers, or other external services once the wallet is set up. The proposal, described in the research paper Simplicity Multisig v0.1 and co-authored with Kyrylo Riabov, uses Simplicity (smart contract language) to extend multisig beyond simple signature collection. Under the design, signers can attach customizable policy conditions to approvals, including whitelists, blacklists, timelocks (delays that restrict when funds can move), compliance checks, spending limits, and veto mechanisms. One example in the paper allows a participant to approve a transaction while preventing execution until a future date. The authors argue that using the blockchain itself as the communication layer could improve reliability because participants only need to scan the chain for signed intents, votes, and coordination messages. Chystiakov also cautioned that the idea may be controversial and is not "privacy-preserving in the best way," and he characterized it as a very early experiment rather than an official Blockstream initiative. The design is built for the Liquid Network, where Simplicity is already available, though the paper says it could later be adapted to Bitcoin if Simplicity is ever adopted there. Formal verification remains in progress, and the paper lists current limitations including no encrypted coordination, descriptor rotation, or confidential transaction support.