Martin R. Albrecht
King's College London

Simone Colombo
King's College London

Benjamin Dowling
King's College London

Rikke Bjerg Jensen
Royal Holloway, University of London

Keywords: at-compromise security, alert blindness, secure messaging, ethnography, security models

Abstract

We start from the observation in prior work that cryptography broadly intuits security goals – as modelled in games or ideal functionalities – while claiming realism. This stands in contrast to cryptography’s attentive approach towards examining assumptions and constructions through cryptanalysis and reductions. To close this gap, we introduce a technique for determining security goals. Given that games and ideal functionalities model specific social relations between various honest and adversarial parties, our methodology is ethnography: a careful social science methodology for studying social relations in their contexts. As a first application of this technique, i.e. ethnography in cryptography, we study security at-compromise (neither pre- nor post-) and introduce the security goal of alert blindness. Specifically, in our 2024/2025 six-and-a-half-month ethnographic fieldwork with protesters in Kenya, we observed that alert blindness captures a security goal of abducted persons who were taken by Kenyan security forces for their presumed activism. We show this notion is achievable under standard assumptions by providing a construction secure in our model. We discussed both the notion and the construction with some interlocutors in Kenya.