The Federal Reserve of St. Louis has published an excellent paper on payment systems and privacy.

Research Fellow Charles Kahn explains why financial privacy is important irrespective of concerns over illicit transactions, and how privacy is being actively eroded as electronic payment systems replace anonymous cash.

Not all of the privacy provided by cash is bad, and if cash disappears we will need new ways of providing that privacy. Because privacy needs are different in type and degree, we should expect a variety of platforms to emerge for specific purposes, and we should expect continued competition between traditional and start-up providers.

He goes on to offer two reasons why the private sector may be better poised to provide future cashless payment privacy than the government: technical expertise and trustworthiness.

First, it’s hard to argue that the central bank will have greater technical skills in protecting privacy (at least in retail transactions; wholesale and infrastructure may be a closer call). The standard regulatory arguments for oversight of payments systems apply, however: There is an easy case for a regulator to be in charge of setting and harmonizing standards for privacy protection.

On the issue of trustworthiness, the answer is more difficult: … Every twist and turn in politics provides an opportunity to justify an examination of one or another aspect of individuals’ transactions. And it is not clear in the current political environment that a central bank or a payments authority will be any stronger at pushing back on these intrusions than private institutions are.

Nor will transparency solve the problem. Paper money is transparent: The technology eliminates the ability of the issuer to monitor transactions, and “it is a truth universally acknowledged” that paper money does so. No computer technology can have this degree of confidence. Only an infinitesimal proportion of people on this planet can verify that computer code does what it advertises it does and only what it advertises. To believe that the CIA has imprinted paper currency with a technology enabling it to report hand-to-hand transactions is paranoia. To believe that spy agencies have backdoors to common computer programs is last week’s news. Generating trust in the privacy promises of a public payments authority’s new electronic money will be an extremely tall order.

He’s also understandably wary of the trustworthiness of private sector payments providers given the lucrative incentives behind customer data collection and monetization. In light of that unfortunate reality, he offers an optimistic balance-of-powers prognosis for privacy:

All institutions, public or private, are likely to be untrustworthy—they are just going to be untrustworthy in different ways. Citizens are not really interested in an absolute guarantee of privacy; we simply want it to be sufficiently difficult to violate privacy that it can be done only in a publicly observed and generally agreed way. Using the differences in objectives of the private and public spheres becomes, it seems to me, a way of making this tension work for us: Public regulation with pushback by private providers seems to me the more hopeful formula.

That’s a reasonable approach, but it also points to an alternative. Rather than looking for trustworthy institutions or pitting one untrustworthy institution against another, perhaps we can use open source software development and open blockchains to build private payment systems that don’t require trustworthy administrators at all! This, it seems to me, is one way to describe the goal of privacy-protecting cryptocurrency projects like Zcash, Monero, and Grin, and it’s why we at Coin Center are so keen on promoting a regulatory climate that does not deny these new technologies the room they need to grow into robust cash alternatives.