Abstract
This paper presents an investigation of the usability and security of the hardware wallet KeepKey 4.2.10. A Man-in-the-Middle (MITM) attack was implemented to simulate potential attacks and evaluate its implications for the wallet's security. In the usability study, ten participants were observed as they used the wallet to complete various Bitcoin address comparison and confirmation tasks. Furthermore, the study examined users' sentiments towards the transaction process of the KeepKey wallet. The results illustrate that the majority of the participants could detect some but not all MITM attacks. Moreover, there were a considerable number of successful MITM attacks in the experiment. From a usability perspective, our findings show that the Keepkey system has some usability issues that should be tackled to enhance the usability and the security of the wallet.