The Feasibility of Dynamically Granted Permissions: Aligning Mobile Privacy with User Preferences

Current smartphone operating systems regulate application permissions by prompting users on an ask-on-first-use basis. Prior research has shown that this method is ineffective because it fails to account for context: the circumstances under which an application first requests access to data may be vastly different than the circumstances under which it subsequently requests access. We performed a longitudinal 131-person field study to analyze the contextuality behind user privacy decisions to regulate access to sensitive resources. We built a classifier to make privacy decisions on the user's behalf by detecting when context has changed and, when necessary, inferring privacy preferences based on the user's past decisions and behavior. Our goal is to automatically grant appropriate resource requests without further user intervention, deny inappropriate requests, and only prompt the user when the system is uncertain of the user's preferences. We show that our approach can accurately predict users' privacy decisions 96.8% of the time, which is a four-fold reduction in error rate compared to current systems.Comment: 17 pages, 4 figure

Proceedings of the Designing interactive secure systems workshop (DISS 2012).

In recent years, the field of usable security has attracted researchers from HCI and Information Security, and led to a better understanding of the interplay between human factors and security mechanisms. Despite these advances, designing systems which are both secure in, and appropriate for, their contexts of use continues to frustrate both researchers and practitioners. One reason is a misunderstanding of the role that HCI can play in the design of secure systems. A number of eminent security researchers and practitioners continue to espouse the need to treat people as the weakest link, and encourage designers to build systems that Homer Simpson can use. Unfortunately, treating users as a problem can limit the opportunities for innovation when people are engaged as part of a solution. Similarly, while extreme characters (such as Homer) can be useful for envisaging different modes of interaction, when taken out of context they risk disenfranchising the very people the design is meant to support. Better understanding the relationship between human factors and the design of secure systems is an important step forward, but many design research challenges still remain. There is growing evidence that HCI design artefacts can be effective at supporting secure system design, and that some alignment exists between HCI, security, and software engineering activities. However, more is needed to understand how broader insights from the interactive system design and user experience communities might also find traction in secure design practice. For these insights to lead to design practice innovation, we also need usability and security evaluation activities that better support interaction design, together with software tools that augment, rather than hinder, these design processes. Last, but not least, we need to share experiences and anecdotes about designing usable and secure systems, and reflect on the different ways of performing and evaluating secure interaction design research. The objective of this workshop is to act as a forum for those interested in the design of interactive secure systems. By bringing together a like-minded community of researchers and practitioners, we hope to share knowledge gleaned from recent research, as well as experiences designing secure and usable systems in practice

Towards a Heuristic Model for Usable and Secure Online Banking

The main purpose of this paper is to propose a heuristic model for usable and secure online banking. The model is based on identified heuristics that contribute to the design of usable security in the context of online banking security. Little research has focused on the balance between usability and security in online banking authentication mechanisms when evaluating the effectiveness of security systems. Nielsen’s ten usability principles are still fundamentally important in designing usable secure systems, as indicated by the analysis of heuristics developed from recent studies. Online banking users are vulnerable to numerous old and new sophisticated online security threats that are increasingly being developed and targeting this unsuspecting group of users. An investigation into this aspect of security design can certainly benefit both the online banking users and online banking merchants, and foster a secure and usable banking environment. In this paper, a heuristic model for usable online banking security is developed, based on security design principles found in literature. Using data collected from users of online banking in South Africa through a questionnaire and banking security personnel interviews, we envisaged refining the identified heuristics and developing a checklist for each heuristic used, for heuristic evaluation by field experts

Attack Surface Reduction for Web Services based on Authorization Patterns

During the design of a security architecture for a web application, the usage of security patterns can assist with fulfilling quality attributes, such as increasing reusability or safety. The attack surface is a common indicator for the safety of a web application, thus, reducing it is a problem during design. Today’s methods for attack surface reduction are not connected to security patterns and have an unknown impact on quality attributes, e.g., come with an undesirable trade-off in functionality. This paper introduces a systematic and deterministic method to reduce the attack surface of web services by deriving service interface methods from authorization patterns. We applied the method to the Participation Service that is part of the KIT Smart Campus system. The resulting RESTful web services of the application are presented and validated

Are my Apps Peeking? Comparing Nudging Mechanisms to Raise Awareness of Access to Mobile Front-facing Camera

Mobile applications that are granted permission to access the device’s camera can access it at any time without necessarily showing the camera feed to the user or communicating that it is being used. This lack of transparency raises privacy concerns, which are exacerbated by the increased adoption of applications that leverage front-facing cameras. Through a focus group we identified three promising approaches for nudging the user that the camera is being accessed, namely: notification bar, frame, and camera preview. We experimented with accompanying each nudging method with vibrotactile and audio feedback. Results from a user study (N=15) show that while using frame nudges is the least annoying and interrupting, but was less understandable than the camera feed and notifications. On the other hand, participants found that indicating camera usage by showing its feed or by using notifications is easy to understand. We discuss how these nudges raise user awareness and the effects on app usage and perception

A taxonomy of attacks and a survey of defence mechanisms for semantic social engineering attacks

Social engineering is used as an umbrella term for a broad spectrum of computer exploitations that employ a variety of attack vectors and strategies to psychologically manipulate a user. Semantic attacks are the specific type of social engineering attacks that bypass technical defences by actively manipulating object characteristics, such as platform or system applications, to deceive rather than directly attack the user. Commonly observed examples include obfuscated URLs, phishing emails, drive-by downloads, spoofed web- sites and scareware to name a few. This paper presents a taxonomy of semantic attacks, as well as a survey of applicable defences. By contrasting the threat landscape and the associated mitigation techniques in a single comparative matrix, we identify the areas where further research can be particularly beneficial

Role-Based Access Control for the Open Grid Services Architecture - Data Access and Integration (OGSA-DAI)

Grid has emerged recently as an integration infrastructure for the sharing and coordinated use of diverse resources in dynamic, distributed virtual organizations (VOs). A Data Grid is an architecture for the access, exchange, and sharing of data in the Grid environment. In this dissertation, role-based access control (RBAC) systems for heterogeneous data resources in Data Grid systems are proposed. The Open Grid Services Architecture - Data Access and Integration (OGSA-DAI) is a widely used framework for the integration of heterogeneous data resources in Grid systems. However, in the OGSA-DAI system, access control causes substantial administration overhead for resource providers in VOs because each of them has to manage the authorization information for individual Grid users. Its identity-based access control mechanisms are severely inefficient and too complicated to manage because the direct mapping between users and privileges is transitory. To solve this problem, (1) the Community Authorization Service (CAS), provided by the Globus toolkit, and (2) the Shibboleth, an attribute authorization service, are used to support RBAC in the OGSA-DAI system. The Globus Toolkit is widely used software for building Grid systems. Access control policies need to be specified and managed across multiple VOs. For this purpose, the Core and Hierarchical RBAC profile of the eXtensible Access Control Markup Language (XACML) is used; and for distributed administration of those policies, the Object, Metadata and Artifacts Registry (OMAR) is used. OMAR is based on the e-business eXtensible Markup Language (ebXML) registry specifications developed to achieve interoperable registries and repositories. The RBAC systems allow quick and easy deployments, privacy protection, and the centralized and distributed management of privileges. They support scalable, interoperable and fine-grain access control services; dynamic delegation of rights; and user-role assignments. They also reduce the administration overheads for resource providers because they need to maintain only the mapping information from VO roles to local database roles. Resource providers maintain the ultimate authority over their resources. Moreover, unnecessary mapping and connections can be avoided by denying invalid requests at the VO level. Performance analysis shows that our RBAC systems add only a small overhead to the existing security infrastructure of OGSA-DAI

Improving Desktop System Security Using Compartmentalization

abstract: Compartmentalizing access to content, be it websites accessed in a browser or documents and applications accessed outside the browser, is an established method for protecting information integrity [12, 19, 21, 60]. Compartmentalization solutions change the user experience, introduce performance overhead and provide varying degrees of security. Striking a balance between usability and security is not an easy task. If the usability aspects are neglected or sacrificed in favor of more security, the resulting solution would have a hard time being adopted by end-users. The usability is affected by factors including (1) the generality of the solution in supporting various applications, (2) the type of changes required, (3) the performance overhead introduced by the solution, and (4) how much the user experience is preserved. The security is affected by factors including (1) the attack surface of the compartmentalization mechanism, and (2) the security decisions offloaded to the user. This dissertation evaluates existing solutions based on the above factors and presents two novel compartmentalization solutions that are arguably more practical than their existing counterparts. The first solution, called FlexICon, is an attractive alternative in the design space of compartmentalization solutions on the desktop. FlexICon allows for the creation of a large number of containers with small memory footprint and low disk overhead. This is achieved by using lightweight virtualization based on Linux namespaces. FlexICon uses two mechanisms to reduce user mistakes: 1) a trusted file dialog for selecting files for opening and launching it in the appropriate containers, and 2) a secure URL redirection mechanism that detects the user’s intent and opens the URL in the proper container. FlexICon also provides a language to specify the access constraints that should be enforced by various containers. The second solution called Auto-FBI, deals with web-based attacks by creating multiple instances of the browser and providing mechanisms for switching between the browser instances. The prototype implementation for Firefox and Chrome uses system call interposition to control the browser’s network access. Auto-FBI can be ported to other platforms easily due to simple design and the ubiquity of system call interposition methods on all major desktop platforms.Dissertation/ThesisDoctoral Dissertation Computer Science 201