Usability of Cryptocurrency Wallets Providing CoinJoin Transactions.

Over the past years, the interest in Blockchain technology and its applications has tremendously increased. This increase of interest was however accompanied by serious threats that raised concerns over user data privacy. Prominent examples include transaction traceability and identification of senders, receivers, and transaction amounts. This resulted in a multitude of privacy-preserving techniques that offer different guarantees in terms of trust, decentralization, and traceability. CoinJoin [19] is one of the promising techniques that adopts a decentralized approach to achieve privacy on the Unspent Transaction Output (UTXO) based blockchain. Despite the advantages of such a technique in obfuscating user transaction data, making them usable to common users requires considerable development and integration efforts. This paper provides a comprehensive usability study of three main Bitcoin wallets that integrate the CoinJoin technique, i.e., Joinmarket, Wasabi, and Samourai. The evaluation includes usability and fundamental design criteria to find the ease of use of these wallets based on cognitive walkthrough during coin mixing. The comparison of the wallets with respect to usability and privacy criteria can be used for future evaluation of privacy wallets. The finding of this study can provide better insights for UTXO-based wallet developers.