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