Towards a secure human-and-computer mutual authentication protocol

We blend research from human-computer interface\ud (HCI) design with computational based crypto-\ud graphic provable security. We explore the notion of\ud practice-oriented provable security (POPS), moving\ud the focus to a higher level of abstraction (POPS+)\ud for use in providing provable security for security\ud ceremonies involving humans. In doing so we high-\ud light some challenges and paradigm shifts required to\ud achieve meaningful provable security for a protocol\ud which includes a human. We move the focus of security ceremonies from being protocols in their context\ud of use, to the protocols being cryptographic building\ud blocks in a higher level protocol (the security cere-\ud mony), which POPS can be applied to. In order to\ud illustrate the need for our approach, we analyse both a\ud protocol proven secure in theory, and a similar proto-\ud col implemented by a �nancial institution, from both HCI and cryptographic perspectives