Animated cover image by @artdesignbySF.
When it comes to defensively guarding the privacy of Bitcoin users, Samourai Wallet has been on the bleeding edge for many years, bringing new features and improvements to users that help achieve anonymity through Whirlpool, its CoinJoin implementation, and to maintain privacy with spending tools like Stowaway, Stonewallx2, Ricochet and PayNyms. Samourai Wallet is also the only Bitcoin wallet to date that has implemented BIP 47.
Additionally, it recently implemented the app-agnostic, Tor-based communication layer Soroban. Soroban brings tremendous UX improvements to users engaging with its collaborative transaction framework, “cahoots,” with tools like Stowaway and Stonewallx2. (Read more about Cahoots transactions and the UX evolution of building the transactions manually versus using Soroban here.)
Maintaining privacy while using Bitcoin requires paying close attention to the way your transactions are being built; which inputs are being used and what kind of history your inputs are bringing with them. Common input ownership heuristics (CIOH) are used by chain analysis companies to surveil Bitcoin users. These heuristics make the assumption that when there are multiple inputs to a Bitcoin transaction, those inputs belong to the same entity. Techniques can be used to break these assumptions, thus rendering the ability of a chain analysis company to maintain such assumptions utterly indefensible.
One technique used in the fight for privacy is a tool brought to you by Samourai Wallet called Stowaway. When someone wants to enhance their privacy while sending bitcoin, they can choose to use Stowaway, which will obfuscate the amount of bitcoin being sent in the transaction.
For example, if Bob wants to send Alice a Stowaway transaction of 0.015 bitcoin, they will both collaborate by providing inputs to the transaction. Then, one output will be given back to Bob as his change and the…