Many in the Bitcoin community seek increased financial privacy. As I wrote in a 2014 study of the Bitcoin ecosystem, “Bitcoin can facilitate more private transactions, which, when legal in the jurisdictions where they occur, are the business of nobody but the parties to them.” That study identified “algorithmic monitoring of Bitcoin transactions” as a rather likely and somewhat consequential threat to the goal of financial privacy (pg. 18). It was part of a cluster of similar threats.
Good news: The Bitcoin community is doing something about it.
The Open Bitcoin Privacy Project recently issued the second edition of its Bitcoin Wallet Privacy Rating Report. It’s a systematic, comparative study of the privacy qualities of Bitcoin wallets. The report is based on a detailed threat model and published criteria for measuring the “privacy strength” of wallets. (I’ve not studied either in detail, but the look of them is well-thought-out.)
Reports like this are an essential, ecosystem-building market function. The OBPP is at once informing Bitcoin users about the quality of various wallets out there, and at the same time challenging wallet providers to up their privacy game. It’s notable that the wallet with the highest number of users, Blockchain, is 17th in the rankings, and one of the most prominent U.S. providers of exchange, payment processing, and wallet services, Coinbase, is 20th. Those kinds of numbers should be a welcome spur to improvement and change. Blockchain is updating its wallet apps. Coinbase, which has offended some users with intensive scrutiny of their financial behavior, appears wisely to be turning away from wallet services.
Bitcoin guru Andreas Antonopolis rightly advises transferring bitcoins to a wallet you control so that you don’t have to trust a Bitcoin company not to lose it. The folks at the Open Bitcoin Privacy Project are working to make wallets more privacy protective. Kudos, OBPP.
There’s more to do, of course, and if there is a recommendation I’d offer for the next OBPP report, it’s to explain in a more newbie-friendly way what the privacy threats are and how to perceive and weigh them. Another threat to the financial privacy outcome goal—ranked slightly more likely and somewhat more consequential than algorithmic monitoring—was: “Users don’t understand how Bitcoin transactions affect privacy.”