Sparrow Wallet, an open-source Bitcoin wallet focused on self-sovereignty and usability, has added support for the Whirlpool CoinJoin implementation in its newest release. Sparrow 1.5.0 allows users to mix unspent transaction outputs (UTXOs) via the new integration, both on the mainnet and testnet Bitcoin networks.
Whirlpool is a Chaumian CoinJoin implementation built by the developers of Samourai Wallet. Like other implementations, it allows Bitcoin users to enjoy forward-looking privacy by breaking assumptions blockchain observers may have about their coins and ownership.
At its core, a CoinJoin is a Bitcoin transaction, albeit a special one, in which different people trustlessly combine their inputs into the same transaction, later receiving their dutiful outputs. It seeks to break transaction heuristics that chain analysis companies use to cluster addresses together in the hopes of breaking the pseudonymity provided by Bitcoin.
By implementing Whirlpool, Sparrow increases the reach of that CoinJoin implementation into more users hence helping increase liquidity in the protocol and, at large, improve the fungibility of all bitcoin. Fungibility is a central aspect of money that prevents two coins, or UTXOs in Bitcoin, from being distinguished from each other or preferred over one another.
Sparrow’s new release also allows users to send their CoinJoin outputs to an external, open wallet after a configurable number of mixing rounds, for example, a cold storage wallet, and an option to optimize transactions for privacy (with Stonewall) or efficiency. Additionally, the desktop wallet now provides a simple privacy analysis of a constructed transaction before sending and a better UX for its Tor integration.
As a censorship-resistant technology, ensuring the fungibility of coins and the privacy of users of the Bitcoin network is paramount to prevent coercion and secure individual liberties. Whereas totalitarian governments have for centuries been able to enforce arbitrary rules due to their control over people’s money, Bitcoin provides people with the power to fight for human rights causes and protect personal freedom.