1,121 research outputs found

    Machine Assisted Proof of ARMv7 Instruction Level Isolation Properties

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    In this paper, we formally verify security properties of the ARMv7 Instruction Set Architecture (ISA) for user mode executions. To obtain guarantees that arbitrary (and unknown) user processes are able to run isolated from privileged software and other user processes, instruction level noninterference and integrity properties are provided, along with proofs that transitions to privileged modes can only occur in a controlled manner. This work establishes a main requirement for operating system and hypervisor verification, as demonstrated for the PROSPER separation kernel. The proof is performed in the HOL4 theorem prover, taking the Cambridge model of ARM as basis. To this end, a proof tool has been developed, which assists the verification of relational state predicates semi-automatically

    A Design and Prototyping of In-Network Processing Platform to Enable Adaptive Network Services

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    The explosive growth of the usage along with a greater diversification of communication technologies and applications imposes the Internet to manage further scalability and diversity, requiring more adaptive and flexible sharing schemes of network resources. Especially when a number of large-scale distributed applications concurrently share the resource, efficacy of comprehensive usage of network, computation, and storage resources is needed from the viewpoint of information processing performance. Therefore, a reconsideration of the coordination and partitioning of functions between networks (providers) and applications (users) has become a recent research topic. In this paper, we first address the need and discuss the feasibility of adaptive network services by introducing special processing nodes inside the network. Then, a design and an implementation of an advanced relay node platform are presented, by which we can easily prototype and test a variety of advanced in-network processing on Linux and off-the-shelf PCs. A key feature of the proposed platform is that integration between kernel and userland spaces enables to easily and quickly develop various advanced relay processing. Finally, on the top of the advanced relay node platform, we implement and test an adaptive packet compression scheme that we previously proposed. The experimental results show the feasibility of both the developed platform and the proposed adaptive packet compression

    Time Protection: the Missing OS Abstraction

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    Timing channels enable data leakage that threatens the security of computer systems, from cloud platforms to smartphones and browsers executing untrusted third-party code. Preventing unauthorised information flow is a core duty of the operating system, however, present OSes are unable to prevent timing channels. We argue that OSes must provide time protection in addition to the established memory protection. We examine the requirements of time protection, present a design and its implementation in the seL4 microkernel, and evaluate its efficacy as well as performance overhead on Arm and x86 processors

    AliEnFS - a Linux File System for the AliEn Grid Services

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    Among the services offered by the AliEn (ALICE Environment http://alien.cern.ch) Grid framework there is a virtual file catalogue to allow transparent access to distributed data-sets using various file transfer protocols. alienfsalienfs (AliEn File System) integrates the AliEn file catalogue as a new file system type into the Linux kernel using LUFS, a hybrid user space file system framework (Open Source http://lufs.sourceforge.net). LUFS uses a special kernel interface level called VFS (Virtual File System Switch) to communicate via a generalised file system interface to the AliEn file system daemon. The AliEn framework is used for authentication, catalogue browsing, file registration and read/write transfer operations. A C++ API implements the generic file system operations. The goal of AliEnFS is to allow users easy interactive access to a worldwide distributed virtual file system using familiar shell commands (f.e. cp,ls,rm ...) The paper discusses general aspects of Grid File Systems, the AliEn implementation and present and future developments for the AliEn Grid File System.Comment: 9 pages, 12 figure

    Procedures and tools for acquisition and analysis of volatile memory on android smartphones

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    Mobile phone forensics have become more prominent since mobile phones have become ubiquitous both for personal and business practice. Android smartphones show tremendous growth in the global market share. Many researchers and works show the procedures and techniques for the acquisition and analysis the non-volatile memory inmobile phones. On the other hand, the physical memory (RAM) on the smartphone might retain incriminating evidence that could be acquired and analysed by the examiner. This study reveals the proper procedure for acquiring the volatile memory inthe Android smartphone and discusses the use of Linux Memory Extraction (LiME) for dumping the volatile memory. The study also discusses the analysis process of the memory image with Volatility 2.3, especially how the application shows its capability analysis. Despite its advancement there are two major concerns for both applications. First, the examiners have to gain root privileges before executing LiME. Second, both applications have no generic solution or approach. On the other hand, currently there is no other tool or option that might give the same result as LiME and Volatility 2.3

    Introducing IPv6 Tokenised Interface Identifiers into the Linux Kernel

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    IPv6 Stateless Address Autoconfiguration (SLAAC) enables network administrators to deploy devices in a network and have those devices automatically generate global addresses without any administrative intervention, and without the need for any stateful configuration service such as DHCPv6. However, certain services --- such as HTTP, SMTP and IMAP --- may better benefit from having "well known" identifiers that do not depend on the physical hardware address of the server's network interface card. Tokenised addresses offer facility for administrators to specify the bottom 64 bits of an IPv6 address for a node whilst allowing the top 64 bits (the network prefix) to be automatically configured from router advertisements. This report documents the approach taken and experience gained from introducing tokenised interface identifiers into the Linux 2.6.11 kernel, as shipped with Redhat Fedora Core 4. This proof of concept work demonstrates the relative ease of introducing this useful utility for network node deployment, and further motivates wider deployment of the semi-automatic configuration approach

    The AliEn system, status and perspectives

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    AliEn is a production environment that implements several components of the Grid paradigm needed to simulate, reconstruct and analyse HEP data in a distributed way. The system is built around Open Source components, uses the Web Services model and standard network protocols to implement the computing platform that is currently being used to produce and analyse Monte Carlo data at over 30 sites on four continents. The aim of this paper is to present the current AliEn architecture and outline its future developments in the light of emerging standards.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 10 pages, Word, 10 figures. PSN MOAT00

    Elearning Technologies

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    When blogging tools first arrived in 1998, people asked “What’s a blog?” The word “blog” is a contraction of “Web log” and is used both as a noun as well as a verb. To blog is to write content to a blog. By design, blogs are best suited for the spontaneous thoughts and observations of an individual or team. They are not designed to facilitate rapid-fire back-and-forth discussion on a particular issue. Blogging tools are available as free or moderately priced services and as products you purchase and install on your own server. You may have noticed recently that many of websites now contain little graphical buttons with the word XML on them. When you click on the button, all you see is some jumbled text and computer code [ed: unless you have a newer web browser or an aggregator]. What's this all about? It's an RSS feed, and it's changing the way people access the Internet.Weblog, RSS, e-learning, RSS, blogging tools
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