Nowadays, the desire to embed more applications in systems as small as smart cards or sensors is growing. However, physical limitations of these systems, like very small main memory, and their cost of production make ...
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ISBN:
(纸本)9780769539676
Nowadays, the desire to embed more applications in systems as small as smart cards or sensors is growing. However, physical limitations of these systems, like very small main memory, and their cost of production make this very difficult to achieve. One solution is to execute code from a secondary memory, cheaper, denser, but slower, such as NAND Flash. Solutions based on Demand-Paging and using a cache in main memory, began to be proposed and implemented in the domain of mobile phones, but consume too much RAM yet, compared to what can provide a smart card. In this paper, we show that we can dramatically increase performance by reducing the size of pages in the cache. This solution then allows a more intelligent access to the NAND. We also show that our solution allows to use Demand-Paging within limits of smart cards memories, where a conventional approach, offering too low bandwidth, makes impossible code execution from this kind of secondary memory.
MACUMBA is an application for SAS®programming developed in house at Bayer. It combines the interactive development features of SAS for Windows, the possibility of a client — server environment and unique ‘state...
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MACUMBA is an application for SAS®programming developed in house at Bayer. It combines the interactive development features of SAS for Windows, the possibility of a client — server environment and unique ‘state of the art’ features that are missing in other SAS development environments. This paper covers some of the unique features that are related to SAS code debugging. This paper will begin by comparing the systems special code execution modes with the way this would be performed in interactive SAS. This paper will continue by presenting an overview of the graphical implementation of the single step debugger for SAS macros and DATA Steps. Finally, this paper will highlight the main issues faced during the development of MACUMBA.
At the end of August, AMD demonstrated a chip that put two of its Opteron processors onto the same piece of silicon. IBM's Power4 already has two processors working alongside each other on a chip; and four of thos...
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At the end of August, AMD demonstrated a chip that put two of its Opteron processors onto the same piece of silicon. IBM's Power4 already has two processors working alongside each other on a chip; and four of those chips go into a supercomputer processing module. Soon, the trickle of general-purpose multiprocessors will become more of a stream.
Cloud computing is a convenient model for processing data remotely. However, users must trust their cloud provider with the confidentiality and integrity of the stored and processed data. To increase the protection of...
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ISBN:
(纸本)9781450389747
Cloud computing is a convenient model for processing data remotely. However, users must trust their cloud provider with the confidentiality and integrity of the stored and processed data. To increase the protection of virtual machines, AMD introduced SEV, a hardware feature which aims to protect code and data in a virtual machine. This allows to store and process sensitive data in cloud environments without the need to trust the cloud provider or the underlying software. However, the virtual machine still depends on the hypervisor for performing certain activities, such as the emulation of special CPU instructions, or the emulation of devices. Yet, most code that runs in virtual machines was not written with an attacker model which considers the hypervisor as malicious. In this work, we introduce a new class of attacks in which a malicious hypervisor manipulates external interfaces of an SEV or SEV-ES virtual machine to make it act against its own interests. We start by showing how we can make use of virtual devices to extract encryption keys and secret data of a virtual machine. We then show how we can reduce the entropy of probabilistic kernel defenses in the virtual machine by carefully manipulating the results of the CPUID and RDTSC instructions. We continue by showing an approach for secret data exfiltration and code injection based on the forgery of MMIO regions over the VM’s address space. Finally, we show another attack which forces decryption of the VM’s stack and uses Return Oriented Programming to execute arbitrary code inside the VM. While our approach is also applicable to traditional virtualization environments, its severity significantly increases with the attacker model of SEV-ES, which aims to protect a virtual machine from a benign but vulnerable hypervisor.
This paper presents an analysis of code implementation performance for image processing algorithms. The test is made for image processing algorithms for robotic arms, but it is suitable for any type of image processin...
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This paper presents an analysis of code implementation performance for image processing algorithms. The test is made for image processing algorithms for robotic arms, but it is suitable for any type of image processing software. Image processing software can use quite big amount of resources, so this way it can be tested which platform, which operating system or which programming language is the most suitable for usage. The image processing task is a color detection task with some line and circle overlays for robotic arm's guidance. The implementations were tested base on code line numbers, code size on disk, binary file size on disk, used memory during execution and used CPU during execution.
Individualized exercises are a promising feature in promoting modern e-learning. The focus of this article is on the QuizPACK system, which is able to generate parameterized exercises for the C language and automatica...
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Individualized exercises are a promising feature in promoting modern e-learning. The focus of this article is on the QuizPACK system, which is able to generate parameterized exercises for the C language and automatically evaluate the correctness of student answers. We introduce QuizPACK and present the results of its comprehensive classroom evaluation during four consecutive semesters. Our studies demonstrate that when QuizPACK is used for out-of-class self-assessment, it is an exceptional learning tool. The students' work with QuizPACK significantly improved their knowledge of semantics and positively affected higher-level knowledge and skills. The students themselves praised the system highly as a learning tool. We also demonstrated that the use of the system in self-assessment mode can be significantly increased by basing later classroom paper-and-pencil quizzes on QuizPACK questions, motivating students to practice them more.
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