Socio-technical formal analysis of TLS certificate validation in modern browsers

Abstract

Abstract-Authenticating a web server is crucial to the security of web browsing. It relies on TLS certificate validation, a property whose enforcement may require getting the user involved. Thus, certificate validation is a socio-technical property -it relies on traditional security technology as well as on social elements such as cultural values, trust and human-computer interaction. Hence the need for an appropriate methodology to study certificate validation from a socio-technical perspective. Certificate validation as carried out through today's most popular browsers -Chrome, Internet Explorer, Firefox and Opera Mini -is first represented by means of UML activity diagrams. It is then translated into CSP#, and expanded with the LTL formalization of four socio-technical properties pivoted on user involvement with certificate validation. The properties are then checked automatically using the PAT model checker. The findings turn out to be far from straightforward and, most importantly, allowed for prototyping a basic methodology for the sociotechnical formal analysis of security properties.

A Conceptual Framework to Study Socio-Technical Security

“…The technical security analysis is applied to elements from UI A till p A and possibly p B till UI B , including the context(s). P A is modelled as a non-deterministic process i.e., interacting with process UI A in every possible way [23,24,9]. The technical analysis, can use formal tools of protocol analysis (e.g., model checking [25]), with the only difference that communications are now multi-layered.…”

Service security and privacy as a socio-technical problem

“…It is the multi-layer approach what makes the analysis socio-technical. The analysis is targeted at complex socio-technical properties centred on the human [17], rather than merely technical ones such as key confidentiality in the traditional sense of security protocol analysis [10]. The findings at the various layers are combined to provide assurances or pinpoint weaknesses to the actual human users of the services.…”

“…Our ceremony concertina traversal methodology, which has already produced valuable findings [17,35], shall be used to fully address these challenges.…”

“…It enables the researcher to take the guarantees of security and privacy that the technology establishes and to transmit them reliably and effectively to its users. For example, Bella et al have recently adopted it to analyse the TLS certificate validation ceremony [17], Huynen et al to identify critical decision points in the ceremonies that users follow to access WiFi networks via Hotspots [35], and Ferreira et al to outline a research framework [34].…”

Socio-technical Security Analysis of Wireless Hotspots

“…We model ceremonies with UML sequence diagrams, a formalism that was successfully applied in socio-technical security analysis of TLS certificates [10]; it visually expresses all the sequential interactions (both Human-Computer and Computer-Computer) run by the players in the ceremony. This modelling is crucial for it defines the sets of interactions that can be analysed individually, in group, or at different levels of inter-dependency.…”