SPE: Security and Privacy Enhancement Framework for Mobile Devices

In this paper, we present a security and privacy enhancement (SPE) framework for unmodified mobile operating systems. SPE introduces a new layer between the application and the operating system and does not require a device be jailbroken or utilize a custom operating system. We utilize an existing ontology designed for enforcing security and privacy policies on mobile devices to build a policy that is customizable. Based on this policy, SPE provides enhancements to native controls that currently exist on the platform for privacy and security sensitive components. SPE allows access to these components in a way that allows the framework to ensure the application is truthful in its declared intent and ensure that the user’s policy is enforced. In our evaluation we verify the correctness of the framework and the computing impact on the device. Additionally, we discovered security and privacy issues in several open source applications by utilizing the SPE Framework. From our findings, if SPE is adopted by mobile operating systems producers, it would provide consumers and businesses the additional privacy and security controls they demand and allow users to be more aware of security and privacy issues with applications on their devices

SPE: Security and Privacy Enhancement Framework for Mobile Devices

In this paper, we present a security and privacy enhancement (SPE) framework for unmodified mobile operating systems. SPE introduces a new layer between the application and the operating system and does not require a device be jailbroken or utilize a custom operating system. We utilize an existing ontology designed for enforcing security and privacy policies on mobile devices to build a policy that is customizable. Based on this policy, SPE provides enhancements to native controls that currently exist on the platform for privacy and security sensitive components. SPE allows access to these components in a way that allows the framework to ensure the application is truthful in its declared intent and ensure that the user’s policy is enforced. In our evaluation we verify the correctness of the framework and the computing impact on the device. Additionally, we discovered security and privacy issues in several open source applications by utilizing the SPE Framework. From our findings, if SPE is adopted by mobile operating systems producers, it would provide consumers and businesses the additional privacy and security controls they demand and allow users to be more aware of security and privacy issues with applications on their devices

A Forensically Sound Adversary Model for Mobile Devices

In this paper, we propose an adversary model to facilitate forensic investigations of mobile devices (e.g. Android, iOS and Windows smartphones) that can be readily adapted to the latest mobile device technologies. This is essential given the ongoing and rapidly changing nature of mobile device technologies. An integral principle and significant constraint upon forensic practitioners is that of forensic soundness. Our adversary model specifically considers and integrates the constraints of forensic soundness on the adversary, in our case, a forensic practitioner. One construction of the adversary model is an evidence collection and analysis methodology for Android devices. Using the methodology with six popular cloud apps, we were successful in extracting various information of forensic interest in both the external and internal storage of the mobile device

Network layer access control for context-aware IPv6 applications

As part of the Lancaster GUIDE II project, we have developed a novel wireless access point protocol designed to support the development of next generation mobile context-aware applications in our local environs. Once deployed, this architecture will allow ordinary citizens secure, accountable and convenient access to a set of tailored applications including location, multimedia and context based services, and the public Internet. Our architecture utilises packet marking and network level packet filtering techniques within a modified Mobile IPv6 protocol stack to perform access control over a range of wireless network technologies. In this paper, we describe the rationale for, and components of, our architecture and contrast our approach with other state-of-the- art systems. The paper also contains details of our current implementation work, including preliminary performance measurements

SoK: A Systematic Review of TEE Usage for Developing Trusted Applications

Trusted Execution Environments (TEEs) are a feature of modern central processing units (CPUs) that aim to provide a high assurance, isolated environment in which to run workloads that demand both confidentiality and integrity. Hardware and software components in the CPU isolate workloads, commonly referred to as Trusted Applications (TAs), from the main operating system (OS). This article aims to analyse the TEE ecosystem, determine its usability, and suggest improvements where necessary to make adoption easier. To better understand TEE usage, we gathered academic and practical examples from a total of 223 references. We summarise the literature and provide a publication timeline, along with insights into the evolution of TEE research and deployment. We categorise TAs into major groups and analyse the tools available to developers. Lastly, we evaluate trusted container projects, test performance, and identify the requirements for migrating applications inside them.Comment: In The 18th International Conference on Availability, Reliability and Security (ARES 2023), August 29 -- September 01, 2023, Benevento, Italy. 15 page

Retrofitting privacy controls to stock Android

Android ist nicht nur das beliebteste Betriebssystem für mobile Endgeräte, sondern auch ein ein attraktives Ziel für Angreifer. Um diesen zu begegnen, nutzt Androids Sicherheitskonzept App-Isolation und Zugangskontrolle zu kritischen Systemressourcen. Nutzer haben dabei aber nur wenige Optionen, App-Berechtigungen gemäß ihrer Bedürfnisse einzuschränken, sondern die Entwickler entscheiden über zu gewährende Berechtigungen. Androids Sicherheitsmodell kann zudem nicht durch Dritte angepasst werden, so dass Nutzer zum Schutz ihrer Privatsphäre auf die Gerätehersteller angewiesen sind. Diese Dissertation präsentiert einen Ansatz, Android mit umfassenden Privatsphäreeinstellungen nachzurüsten. Dabei geht es konkret um Techniken, die ohne Modifikationen des Betriebssystems oder Zugriff auf Root-Rechte auf regulären Android-Geräten eingesetzt werden können. Der erste Teil dieser Arbeit etabliert Techniken zur Durchsetzung von Sicherheitsrichtlinien für Apps mithilfe von inlined reference monitors. Dieser Ansatz wird durch eine neue Technik für dynamic method hook injection in Androids Java VM erweitert. Schließlich wird ein System eingeführt, das prozessbasierte privilege separation nutzt, um eine virtualisierte App-Umgebung zu schaffen, um auch komplexe Sicherheitsrichtlinien durchzusetzen. Eine systematische Evaluation unseres Ansatzes konnte seine praktische Anwendbarkeit nachweisen und mehr als eine Million Downloads unserer Lösung zeigen den Bedarf an praxisgerechten Werkzeugen zum Schutz der Privatsphäre.Android is the most popular operating system for mobile devices, making it a prime target for attackers. To counter these, Android’s security concept uses app isolation and access control to critical system resources. However, Android gives users only limited options to restrict app permissions according to their privacy preferences but instead lets developers dictate the permissions users must grant. Moreover, Android’s security model is not designed to be customizable by third-party developers, forcing users to rely on device manufacturers to address their privacy concerns. This thesis presents a line of work that retrofits comprehensive privacy controls to the Android OS to put the user back in charge of their device. It focuses on developing techniques that can be deployed to stock Android devices without firmware modifications or root privileges. The first part of this dissertation establishes fundamental policy enforcement on thirdparty apps using inlined reference monitors to enhance Android’s permission system. This approach is then refined by introducing a novel technique for dynamic method hook injection on Android’s Java VM. Finally, we present a system that leverages process-based privilege separation to provide a virtualized application environment that supports the enforcement of complex security policies. A systematic evaluation of our approach demonstrates its practical applicability, and over one million downloads of our solution confirm user demand for privacy-enhancing tools