User-visible cryptography in email and web scenarios

Purpose To classify different types of “user-visible cryptography” and evaluate the value of user-visible cryptographic mechanisms in typical email and web scenarios for non-expert IT users. Design/methodology/approach We review the existing literature, then identify user stories typical to our users of interest. We analyse the risks, mitigations of risks and the limits of those mitigations in the user stories. Findings The scenarios identified suggest that background, opportunistic encryption has value, but more explicit, user-visible cryptographic mechanisms do not provide any further mitigation. Other mechanisms beyond technological mitigations provide the required mitigation for our users. Research limitations/implications Further work should be carried out on the trust issues with trusted third parties, as they are intrinsic to global, automated cryptographic mechanisms. We suggest that deployed systems should rely on automation rather than exp licit user involvement; further work on how best to involve users effectively remains valuable. Practical implications Deployed systems should rely on automation rather than explicit user dialogues. This follows from recognised aspects of user behaviour, such as ignoring dialogues and unconsciously making a holistic assessment of risk that is mostly mitigated by social factors. Social implications The user populations concerned rely significantly on the existing legal and social infrastructure to mitigate some risks, such as those associated with e-commerce. Guarantees from third parties and the existence of fallback procedures improve user confidence. Originality/value This work uses user stories as a basis for a holistic review of the issues surrounding the use of cryptography. We concentrate on a relatively large population (non-expert IT users) carrying out typical tasks (web and email).