"Fast, Easy, Convenient." Studying Adoption and Perception of Digital Covid Certificates.

Digital vaccination, recovery, and test certificates play an important role in enforcing access restrictions to certain parts of the public life in Europe during the current phase of the COVID-19 pandemic. Such certificates represent an interesting showcase for digital security and privacy in the context of sensitive personal data. In this paper, we take a look at which types of certificates and related apps people in Germany use for which purposes, which factors influence their adoption, and which misconceptions exist concerning the security and use of certificates. To this end, we report the results of a census-representative online survey in Germany ( n = 800) conducted in December 2021, complemented with 30 qualitative street interviews. Most participants favor digital certificates over paper-based variants due to their ease of use and seamless integration into dedicated smartphone apps - more than 75% of participants have installed one or more eligible app(s) on their phone. We find that older age, higher privacy concerns related to apps, and not being vaccinated are factors hindering the adoption of digital certificates.