Encryption for the masses? An analysis of PGP key usage

Despite the rise of alternatives, email remains integral to technology-mediated communication. To protect email privacy the encryption software Pretty Good Privacy (PGP) has been considered the first choice for individuals since 1991. However, there is little scholarly insight into the characteristics and motivations for the people using PGP. We seek to shed light on social aspects of PGP: who is using PGP for encrypted email communication, how and why? By understanding those using the technology, questions on the motivations, usability, and the political dimension of communication encryption can be contextualized and cautiously generalized to provide input for the design of privacy-enhancing technologies. We have greatly extended the scale and scope of existing research by conducting a PGP key analysis on 4.27 million PGP public keys complemented by a survey filled out by former and current PGP users (N = 3,727). We show that a relatively small homogeneous population of mainly western, technically skilled, and moderately politically active males is using PGP for privacy self-management. Additionally, findings from existing research identifying poor usability and a lack of understanding of the underlying mechanisms of PGP can be confirmed.