• Commerceblock’s Mercury Wallet introduced a new mixing tool, statechains, and Coinswaps.
• Statechains are an off-chain mechanism for transferring freely between anyone completely off-chain.
• Statechains use ECDSA-MPC addresses, timelocked pre-signed withdrawal transactions, and cryptographic key-sharing to keep funds secure.

Commerceblock’s Mercury Wallet was a revolutionary implementation of both statechains and CoinSwaps. This wallet provided a new mixing tool, as well as the first wallet to implement a new second-layer scaling solution. Statechains offer a new way of sending and receiving digital assets securely and privately.

Statechains are an off-chain mechanism for transferring freely between anyone completely off-chain. This technology was initially proposed by Ruben Somsen and was then implemented within the Mercury Wallet. The statechain uses a combination of ECDSA-MPC addresses, timelocked pre-signed withdrawal transactions, and cryptographic key-sharing to keep funds secure. To start a statechain, the original owner/user collaborates with a statechain operator to construct an ECDSA-MPC address. This address is then assigned a private key which is split into two parts, one half being held by the user and the other half being held by the operator. The user then creates a timelocked, pre-signed withdrawal transaction which is signed by the operator before sending funds to the new address. This timelocked transaction allows the user to unilaterally take the coins back after the timelock period has expired.

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. This cryptography ensures that the operator’s new keyshare will only work with the new user’s keyshare, and if the old one is deleted then it is not even possible for them to collaborate with the old user to spend the coins.

The Mercury Wallet also integrates a new CoinSwap design which allows users to mix multiple times without needing to transact on chain for each mix. This CoinSwap design is a trustless system which uses atomic swaps and cryptographic proofs of ownership, allowing users to mix and match their coins without trusting any third party.

Overall, Commerceblock’s Mercury Wallet has revolutionized the way digital assets are sent and received by introducing statechains and CoinSwaps. These new technologies have enabled users to securely and privately transfer digital assets while also providing them with a trustless mixing tool which allows them to remain anonymous. With these new tools, the Mercury Wallet has established a new standard of digital asset management.