Finding Convex Hulls Using Quickhull on the GPU

We present a convex hull algorithm that is accelerated on commodity graphics hardware. We analyze and identify the hurdles of writing a recursive divide and conquer algorithm on the GPU and divise a framework for representing this class of problems. Our framework transforms the recursive splitting step into a permutation step that is well-suited for graphics hardware. Our convex hull algorithm of choice is Quickhull. Our parallel Quickhull implementation (for both 2D and 3D cases) achieves an order of magnitude speedup over standard computational geometry libraries.Comment: 11 page

Modeling Quantum Optical Components, Pulses and Fiber Channels Using OMNeT++

Quantum Key Distribution (QKD) is an innovative technology which exploits the laws of quantum mechanics to generate and distribute unconditionally secure cryptographic keys. While QKD offers the promise of unconditionally secure key distribution, real world systems are built from non-ideal components which necessitates the need to model and understand the impact these non-idealities have on system performance and security. OMNeT++ has been used as a basis to develop a simulation framework to support this endeavor. This framework, referred to as "qkdX" extends OMNeT++'s module and message abstractions to efficiently model optical components, optical pulses, operating protocols and processes. This paper presents the design of this framework including how OMNeT++'s abstractions have been utilized to model quantum optical components, optical pulses, fiber and free space channels. Furthermore, from our toolbox of created components, we present various notional and real QKD systems, which have been studied and analyzed.Comment: Published in: A. F\"orster, C. Minkenberg, G. R. Herrera, M. Kirsche (Eds.), Proc. of the 2nd OMNeT++ Community Summit, IBM Research - Zurich, Switzerland, September 3-4, 201

Android security framework : enabling generic and extensible access control on Android

We introduce the Android Security Framework (ASF),a generic, extensible security framework for Android that enables the development and integration of a wide spectrum of security models in form of code-based security modules. The design of ASF reflects lessons learned from the literature on established security frameworks (such as Linux Security Modules or the BSD MAC Framework) and intertwines them with the particular requirements and challenges from the design of Android’s software stack. ASF provides a novel security API that supports authors of Android security extensions in developing their modules. This overcomes the current unsatisfactory situation to provide security solutions as separate patches to the Android software stack or to embed them into Android’s mainline codebase. As a result, ASF provides different practical benefits such as a higher degree of acceptance, adaptation, and maintenance of security solutions than previously possible on Android. We present a prototypical implementation of ASF and demonstrate its effectiveness and efficiency by modularizing different security models from related work, such as context-aware access control, inlined reference monitoring, and type enforcement

CAMORRA: a C++ library for recursive computation of particle scattering amplitudes

We present a new Monte Carlo tool that computes full tree-level matrix elements in high-energy physics. The program accepts user-defined models and has no restrictions on the process multiplicity. To achieve acceptable performance, CAMORRA evaluates the matrix elements in a recursive way by combining off-shell currents. Furthermore, CAMORRA can be used to compute amplitudes involving continuous color and helicity final states.Comment: 22 page

ACMiner: Extraction and Analysis of Authorization Checks in Android's Middleware

Billions of users rely on the security of the Android platform to protect phones, tablets, and many different types of consumer electronics. While Android's permission model is well studied, the enforcement of the protection policy has received relatively little attention. Much of this enforcement is spread across system services, taking the form of hard-coded checks within their implementations. In this paper, we propose Authorization Check Miner (ACMiner), a framework for evaluating the correctness of Android's access control enforcement through consistency analysis of authorization checks. ACMiner combines program and text analysis techniques to generate a rich set of authorization checks, mines the corresponding protection policy for each service entry point, and uses association rule mining at a service granularity to identify inconsistencies that may correspond to vulnerabilities. We used ACMiner to study the AOSP version of Android 7.1.1 to identify 28 vulnerabilities relating to missing authorization checks. In doing so, we demonstrate ACMiner's ability to help domain experts process thousands of authorization checks scattered across millions of lines of code

Analysis of safety critical plc code against IEC 1508 development techniques

The aim of this thesis is to assess the applicability of recommended software development techniques defined in IEC 1508 [8] to PLC (Programmable Logic Controller) code developed for offshore oil platforms. The draft standard TEC 1508 contains specific recommendations which have the objective of improving the safety characteristics of safety critical code The recommended techniques could have one of the following characteristics with regard to offshore PLC code: • They are already used in the development of code. • They could be used in the development of the code. • They could not be used due to the application domain. • They could not be used due to the specific programming environment analysed. It was the aim of the thesis to characterise a subset of the IEC 1508 techniques into the above categories. The analysis was requested by the Health and Safety Executive (HSE) Offshore Division. The analysis has been performed using two major case studies, taken from live industrial safety-critical systems operating on a North Sea Oil Platform; they both comprise 300K lines of code in total. Both systems were written in three high level PLC languages. It was decided to translate the code into one language, so the analysis was undertaken in terms of a single language. A translator has been written, and a number of static analysis tools, therefore allowing all the code to be analysed. The key twenty two recommendations from IEC 1508 have been selected, and the case study systems correspondingly analysed, using a modified Goal Question Metric (GQM) approach as a unified framework. The overall analysis method has been found to be successful in supporting the detailed analysis of IEC 1508 recommendations. The thesis presents detailed conclusions on each analysed technique, as well as more general observations on the PLC code