Efficient emergency communication is of high practical importance, but has specific challenges: unpredictable local emergency situations harden the establishment of communication structures, legal requirements dictate the use of endto-end secure and documentable approaches, while users demand ease-of-use and privacy protection. Dealing with these challenges, the contribution of this paper is four-fold: first, together with emergency practioners we define realistic security requirements and patterns for ubiquitous emergency communication. Second, we devise techniques for privacyrespecting re-identificaton of pseudonymous receivers. Third, we propose a new hybrid encryption technique for expressive policies, which combines ciphertext-policy attribute-based encryption with location-based encryption. Fourth, building on the new techniques, we introduce MundoMessage, our approach to multilaterally end-to-end secure, user-friendly attribute-based messaging for emergency communication. F...
Stefan G. Weber, Yulian Kalev, Sebastian Ries, Max