3,305 research outputs found
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
It's TEEtime: A New Architecture Bringing Sovereignty to Smartphones
Modern smartphones are complex systems in which control over phone resources
is exercised by phone manufacturers, OS vendors, and users. These stakeholders
have diverse and often competing interests. Barring some exceptions, users
entrust their security and privacy to OS vendors (Android and iOS) and need to
accept their constraints. Manufacturers protect their firmware and peripherals
from the OS by executing in the highest privilege and leveraging dedicated CPUs
and TEEs. OS vendors need to trust the highest privileged code deployed by
manufacturers. This division of control over the phone is not ideal for OS
vendors and is even more disadvantageous for the users. Users are generally
limited in what applications they can install on their devices, in the privacy
model and trust assumptions of the existing applications, and in the
functionalities that applications can have.
We propose TEEtime, a new smartphone architecture based on trusted execution
allowing to balance the control different stakeholders exert over phones. More
leveled control over the phone means that no stakeholder is more privileged
than the others. In particular, TEEtime makes users sovereign over their
phones: It enables them to install sensitive applications in isolated domains
with protected access to selected peripherals alongside an OS. TEEtime achieves
this while maintaining compatibility with the existing smartphone ecosystem and
without relying on virtualization; it only assumes trust in a phone's firmware.
TEEtime is the first TEE architecture that allows isolated execution domains to
gain protected and direct access to peripherals. TEEtime is based on Armv8-A
and achieves peripheral isolation using a novel mechanism based on memory and
interrupt controller protection. We demonstrate the feasibility of our design
by implementing a prototype of TEEtime, and by running exemplary sensitive
applications
After Over-Privileged Permissions: Using Technology and Design to Create Legal Compliance
Consumers in the mobile ecosystem can putatively protect their privacy with the use of application permissions. However, this requires the mobile device owners to understand permissions and their privacy implications. Yet, few consumers appreciate the nature of permissions within the mobile ecosystem, often failing to appreciate the privacy permissions that are altered when updating an app. Even more concerning is the lack of understanding of the wide use of third-party libraries, most which are installed with automatic permissions, that is permissions that must be granted to allow the application to function appropriately. Unsurprisingly, many of these third-party permissions violate consumers’ privacy expectations and thereby, become “over-privileged” to the user. Consequently, an obscurity of privacy expectations between what is practiced by the private sector and what is deemed appropriate by the public sector is exhibited. Despite the growing attention given to privacy in the mobile ecosystem, legal literature has largely ignored the implications of mobile permissions. This article seeks to address this omission by analyzing the impacts of mobile permissions and the privacy harms experienced by consumers of mobile applications. The authors call for the review of industry self-regulation and the overreliance upon simple notice and consent. Instead, the authors set out a plan for greater attention to be paid to socio-technical solutions, focusing on better privacy protections and technology embedded within the automatic permission-based application ecosystem
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