The Value of User-Visible Internet Cryptography

Cryptographic mechanisms are used in a wide range of applications, including email clients, web browsers, document and asset management systems, where typical users are not cryptography experts. A number of empirical studies have demonstrated that explicit, user-visible cryptographic mechanisms are not widely used by non-expert users, and as a result arguments have been made that cryptographic mechanisms need to be better hidden or embedded in end-user processes and tools. Other mechanisms, such as HTTPS, have cryptography built-in and only become visible to the user when a dialogue appears due to a (potential) problem. This paper surveys deployed and potential technologies in use, examines the social and legal context of broad classes of users, and from there, assesses the value and issues for those users

User-visible cryptography in email and web scenarios

Purpose– This paper aims to classify different types of “user-visible cryptography” and evaluate the value of user-visible cryptographic mechanisms in typical email and web scenarios for non-expert IT users.Design/methodology/approach– The authors review the existing literature, and then identify user stories typical to their users of interest. They analyse the risks, mitigations of risks and the limits of those mitigations in the user stories.Findings– The scenarios identified suggest that background, opportunistic encryption has value, but more explicit, user-visible cryptographic mechanisms do not provide any further mitigation. Other mechanisms beyond technological mitigations provide the required mitigation for the users.Research limitations/implications– Further work should be carried out on the trust issues with trusted third parties, as they are intrinsic to global, automated cryptographic mechanisms. The authors suggest that deployed systems should rely on automation rather than explicit user involvement; further work on how best to involve users effectively remains valuable.Practical implications– Deployed systems should rely on automation rather than explicit user dialogues. This follows from recognised aspects of user behaviour, such as ignoring dialogues and unconsciously making a holistic assessment of risk that is mostly mitigated by social factors.Social implications– The user populations concerned rely significantly on the existing legal and social infrastructure to mitigate some risks, such as those associated with e-commerce. Guarantees from third parties and the existence of fallback procedures improve user confidence.Originality/value– This work uses user stories as a basis for a holistic review of the issues surrounding the use of cryptography. The authors concentrate on a relatively large population (non-expert IT users) carrying out typical tasks (web and email).</jats:sec

FriendlyMail: Confidential and Verified Emails among Friends

Despite being one of the most basic and popular Internet applications, email still largely lacks user-to-user cryptographic protections. From a research perspective, designing privacy-preserving techniques for email services is complicated by the requirement of balancing security and ease-of-use needs of everyday users. For example, users cannot be expected to manage long-term keys (e.g., PGP key-pair), or understand crypto primitives. To enable intuitive email protections for a large number of users, we design FriendlyMail by leveraging existing relationships between a sender and receiver on an online social networking (OSN) site. FriendlyMail can pro- vide integrity, authentication and confidentiality guarantees for user-selected messages among OSN friends. A confidentiality-protected email is encrypted by a randomly-generated key, and the key and hash of the encrypted content are privately shared with the receiver via the OSN site. Our implementation consists of a Firefox addon and a Facebook app, and can secure the web-based Gmail service using Facebook as the OSN site; the addon is available at: https://madiba.encs.concordia.ca/software/friendlymail/. However, the design can be implemented for preferred email/OSN services as long as the email and OSN providers are non-colluding parties. FriendlyMail is a client-end solution and does not require changes to email or OSN servers. In contrast to most other solutions, we limit our target user base to existing OSN users, to facilitate ease of adoption. In this paper, the focus of our discussion includes: the design, implementation and security analysis of the proposed solution. We acknowledge that a user study will be required to validate usability-related features of FriendlyMail. We are currently considering a comprehensive user study as separate future work; cf. past such studies of PGP (Whitten and Tygar, USENIX Security 1999), S/MIME (Garfinkel and Miller, SOUPS 2005)

The usability of knowledge based authentication methods on mobile devices

Mobile devices are providing ever increasing functionality to users, and the risks associated with applications storing personal details are high. Graphical authentication methods have been shown to provide better security in terms of password space than traditional approaches, as well as being more memorable. The usability of any system is important since an unusable system will often be avoided. This thesis aims to investigate graphical authentication methods based on recall, cued recall and recognition memory in terms of their usability and security