Mercury Wallet: Unlocking Privacy, Scalability, and Off-Chain Transfers

– Commerceblock introduced Mercury Wallet, an implementation of both statechains and CoinSwaps.
– Statechains are an off-chain mechanism for transferring freely between anyone completely off-chain.
– The wallet integrated a new CoinSwap design to allow users to mix multiple times without needing to transact on chain for each mix.

Commerceblock recently introduced Mercury Wallet, an innovative implementation of both statechains and CoinSwaps. This new wallet simultaneously introduced a new mixing tool as well as the first wallet to implement a new second-layer scaling solution. The team built off of Ruben Somsen’s original statechain proposal with some changes to make it work without the needed ANYPREVOUT/Eltoo sighash flag, and integrated a new CoinSwap design to allow users to mix multiple times without needing to transact on chain for each mix.

Statechains are an off-chain mechanism for transferring freely between anyone completely off-chain. This is done by constructing a ECDSA-MPC address where the private key is sharded with one half held by the user and the other half by the operator. This then creates a timelocked, pre-signed withdrawal transaction that allows the user to unilaterally take the coins back after the timelock. When the user wishes to transfer the statechain, they notify the operator who then collaborates with the receiver. The receiver and operator generate a new set of private key shares that correspond with the same address, and generate a new pre-signed transaction with a lower timelock than the last one, and then the operator deletes their old keyshare.

CoinSwap is a trustless mechanism to swap coins between two users without broadcasting anything on the blockchain. This is done by creating two transactions with a mutual output, and then signing both transactions. Then, the two users exchange the signatures, and the transaction is broadcasted and the coins are swapped. This integration with Mercury Wallet allows users to mix multiple times without needing to transact on chain for each mix.

Overall, the introduction of Mercury Wallet is a groundbreaking development in the cryptocurrency space. It opens up the possibilities of increasing privacy, scalability, and off-chain transfers, all without sacrificing the security of blockchain. This is just the beginning of what can be achieved with this new technology, and it will be exciting to see what comes next.