NDSS

Holistic Privacy and Usability of a Cryptocurrency Wallet

Harry Halpin (Nym Technologies)

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.