Introducing Mercury Wallet: Secure and Private Mixing Tool

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• Commerceblock introduced Mercury Wallet, an implementation of both statechains and CoinSwaps, as a new mixing tool and the first wallet to use a second-layer scaling solution.
• Statechains are an off-chain mechanism for transferring freely between anyone completely off-chain.
• 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.

Commerceblock recently released their Mercury Wallet, an innovative implementation of both statechains and CoinSwaps. This groundbreaking new wallet offers a new mixing tool as well as being the first wallet to use a second-layer scaling solution.

Statechains are a revolutionary off-chain mechanism for transferring funds freely between anyone, completely off-chain. The original owner/user collaborates with a statechain operator to construct an ECDSA-MPC address where the private key is sharded between the user and the operator. Then a timelocked, pre-signed withdrawal transaction is created and signed with the operator before sending funds to the new address. Neither side completely controls the private key, and the user has a pre-signed transaction that allows them 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. The cryptography works in such a way that the operator’s new keyshare will only work with the new user’s keyshare. As a result, if the operator deletes the old one, it is not possible for them to collaborate with the old user to spend the coins.

The integration of this new CoinSwap design allows users to mix multiple times without needing to transact on chain for each mix. This makes Mercury Wallet a powerful tool for those looking to increase the privacy and security of their funds.

Commerceblock has taken Ruben Somsen’s original statechain proposal and applied some changes to make it work without the needed ANYPREVOUT/Eltoo sighash flag. This new wallet is an important step forward in the world of cryptocurrency and an exciting development in the world of privacy and security.