Shrink-Wrapped Security: Tightly Coupling Situation and Security

The mobile workforce, which consists of employees that do not have one fixed place of work and are linked to a corporate base using a mobile computing device, is expected to grow to 75% of the total United States workforce, or approximately 212.1 million people, by 2015. Advances in technology, such as the increasing abundance of portable computing devices and the prevalence of wireless broadband, combined with the fact that more companies are allowing employees to use their own devices to access the enterprise, create an environment in which these workers can access corporate resources anytime, anywhere, with a myriad of devices having varying configurations. Having ubiquitous access to resources has its benefits, like increased productivity, but also creates unique challenges to ensuring appropriate security. Traditional approaches to security are not suitable for this emerging computing environment, because they are based on assumptions that no longer hold, such as well-defined situations, consistent configurations, and static contexts. For this reason, these approaches typically base security decisions on statically assigned attributes like identity or role. In the highly dynamic computing environment of mobile workers, context-aware security, in which context is utilized to allow security to adapt to the current situation, is essential. This dissertation presents our efforts to address the mismatch between traditional, context-insensitive security and this emerging dynamic computing environment with a novel security paradigm, shrink-wrapped security. With shrink-wrapped security, as the situation changes, the security changes also, providing a tight coupling between a user's current situation and security. Contributions of this dissertation include the following: *A novel security paradigm, shrink-wrapped security, which involves utilizing context to tightly fuse a user's situation and security. *A usable definition of security-relevant context, along with goal oriented guidelines and a corresponding taxonomy to facilitate the systematic identification of contextual attributes that are most pertinent to a security service. These contributions deal with a key challenge of context-aware system development- identifying relevant context. *A context acquisition and management framework to facilitate the development and use of shrink-wrapped security services for the mobile workforce. The layered architecture of this framework supports secure context acquisition and utilization by security services and was designed with the resource constraints of mobile devices in mind. *An approach based on logic programming to practically incorporate the use of security-relevant context into the security policies that govern security services. This technique is aligned with the shrink-wrapped security concept of utilizing a comprehensive set of relevant context, while remaining practical and manageable by abstracting relevant contextual attributes to a security level associated with the objectives of a security service. *The implementation and evaluation of shrink-wrapped access control, which serves as a practical demonstration of the feasibility of shrink-wrapped security

An architecture for deriving and implementing context-dependent security measures on mobile devices

Aufgrund der steigenden Nutzung mobiler Geräte und der Vielzahl persönlicher bzw. geschäftlicher Daten, die auf mobilen Geräte gespeichert und verarbeitet werden, sind mobile Geräte zu einem attraktiven Angriffsziel geworden. Ungeachtet des Schutzbedarfs hat sich die Sicherheitssoftware, wie man sie von stationären Systemen her kennt, auf mobilen Geräten bisher nicht durchsetzen können. Sicherheitsansätze stationärer Systeme können mobile Geräte zwar vor Bedrohungen schützen, jedoch sind diese Ansätze zu ressourcenintensiv für mobile Geräte, deren Rechenleistung und Akkukapazität relativ begrenzt ist. Um den Schutzbedarf mobiler Geräte und deren Anwendungen unter Berücksichtigung der begrenzten Ressourcen zu erfüllen, wird in dieser Arbeit ein Architekturmodell konzipiert, das Anwendungen, abhängig von Bedrohungen, Sicherheitsmaßnahmen bereitstellt. Anders als beim Sicherheitsansatz stationärer Systeme werden nur die Sicherheitsmaßnahmen umgesetzt, die aufgrund der aktuellen Bedrohungen notwendig sind. Ermöglicht wird die adaptive Bereitstellung von Sicherheitsmaßnahmen durch einen in dieser Arbeit vorgestellten Ansatz, der die Ermittlung von Bedrohungen und geeigneter Maßnahmen aus Kontextinformationen und Erfahrungswerten zulässt. Zuletzt wird die Realisierbarkeit des Architekturmodells anhand einer prototypischen Implementierung nachgewiesen.Due to the increased use of mobile devices and due to multiplicity of private as well as business data which is stored and processed on mobile devices, the latter are becoming an attractive target for attacks. Regardless of the needs for protection, security software, as known from stationary systems, has not become accepted yet. Security approaches of stationary systems are able to protect mobile devices against threats, but these approaches are too resource-intensive for mobile devices because its computing power and battery capacity is relatively limited. To fulfil security requirements of mobile devices and their applications, considering their limited resources, this work depicts an architecture model which provides security measures to applications, depending on threats. Unlike the stationary approach of security systems, only those security measures are executed that are necessary due to the currently existing threats. The adaptive deployment of security measures is enabled by an approach introduced in this work, that allows the identification of threats and appropriate actions based on context information and experiences. Finally, the feasibility of the architectural model is demonstrated by a prototype

Modeling Context Information in Mobile Usage Scenarios. An Approach for Integration of security-relevant User Activity.

Um einen zuverlässigen kontext-sensitiven Sicherheitsdienst bereitzustellen, ist die Vollständigkeit des zur Bewertung genutzten Sicherheitskontextes von wesentlicher Bedeutung. Der Anwendungskontext leistet dazu einen fundamentalen Beitrag. Aufgrund der fehlenden Interpretationslogik ist allerdings der Anwendungskontext von aussen nicht ermittelbar. Die Integration einer den Sicherheitsdienst unterstützenden Komponente in die Anwendung schafft hierzu auf zweierlei Weise Abhilfe. Sie stellt Anwendungskontextinformationen zur Verfügung und gewährleistet effektiv eine kontext-sensitive Sicherheitsadaption.The completeness of the security context is crucial to provide a reliable context-aware security service. The application context makes a fundamental contribution. Due to the lack of interpretation logic the application context can not be determined from outside. The integration of a security component into the application helps here in two ways. It provides application context information and ensures effective context-aware security adaptation