  In this study, we overview the problems associated with the usability of
cryptocurrency wallets, such as those used by ZCash, for end-users. The concept
of "holistic privacy," where information leaks in one part of a system can
violate the privacy expectations of different parts of the system, is
introduced as a requirement. To test this requirement with real-world software,
we did a 60 person task-based evaluation of the usability of a ZCash
cryptocurrency wallet by having users install and try to both send and receive
anonymized ZCash transactions, as well as install a VPN and Tor. While the
initial wallet installation was difficult, we found even a larger amount of
difficulty integrating the ZCash wallet into network-level protection like VPNs
or Tor, so only a quarter of users could complete a real-world purchase using
the wallet.
