<p>In this report hardware based alternatives to password authentication in a Windows domain are evaluated for the needs of a certain company. In order to investigate the demands on such alternatives interviews with people concerned have been carried out. The demands which resulted from the interviews have been used to select types of hardware tokens for evaluation. Two products which offer authentication with smart cards and USB tokens have been selected and closer evaluated. These are RSA Passage which offers both hardware options and Rainbow iKey which uses USB tokens. Both products are evaluated based on the demands and additional evaluation criteria. The information from the evaluations is used to compare the products.</p>

<p>The purpose of this report is to implement and evaluate parts of the simulation software used in the SoCBUS project. In order to complete and evaluate the entire software package, a traffic model and a stimuli generator must be implemented. They are implemented and evaluated together with the entire simulator software. The purpose of the Traffic model is to model communication traffic as good and descriptive as possible. The output of the Traffic model is called a test case, which works as input for the Stimuli generator. The Stimuli generator computes and creates an event list for the Simulator. This report will investigate and motivate the presented traffic model and stimuli generator in detail. The simulator software is then tested with two separate test cases in order to investigate if the simulator software works properly. The results are promising and the simulator software behaves as expected.</p>

<p>This degree project is made for Sundbyholms Golf&Country Club in Eskilstuna. The aim of the report is to produce a website which include a golf course interactive guide and an online game. Programs that have been used during the project are Adobe Photoshop, Macromedia Dreamweaver, Macromedia Director, Discreet 3DS Max and the plug-in 3DS Max Exporter. The choice of programs are based on experience and knowledge from the university education Media and Communication Engineering at Linköping University. </p><p>The golf course guide contains a 2D-guide (image) and a 3D-guide (interactive image). The guides have an image overview of each hole, with liked key points to photograph’s. The photos gives the user a physical view of the course. In the 3D-guide the visitor can “look around” in the view. The interactiv photo is created in 3DS Max combined with Director. The online game, Minituregolf, was programed in Directors own language Lingo.</p>

<p>This Master Thesis presents the design of the core of a fixed point general purpose multimedia DSP processor (MDSP) and its instruction set. This processor employs parallel processing techniques and specialized addressing models to speed up the processing of multimedia applications. </p><p>The MDSP has a dual MAC structure with one enhanced MAC that provides a SIMD, Single Instruction Multiple Data, unit consisting of four parallel data paths that are optimized for accelerating multimedia applications. The SIMD unit performs four multimedia- oriented 16- bit operations every clock cycle. This accelerates computationally intensive procedures such as video and audio decoding. The MDSP uses a memory bank of four memories to provide multiple accesses of source data each clock cycle.</p>

<p>The Global System for Mobile Communications (GSM) is the most widely used cellular technology in the world. Approximately 800 million people around the world are using GSM for different purposes, but mostly for voice communication and SMS. For GSM, like many other widely used systems, security is crucial. The security involves mechanisms used to protect the different shareholders, like subscribers and service providers. The aspects of security that this report covers are mainly anonymity, authentication and confidentiality. </p><p>The important aspects of the system that need protection are described, along with the implementation of mechanisms used for the protection. It appears that many of the very valuable aspects of GSM can be attacked. </p><p>The anonymity of a GSM user is compromised resulting in the attacker being able to observe the time, rate, length, sources or destinations of e g calls. Even tracking a subscriber’s movements becomes possible. However, a passive attack is not sufficient to perform these attacks. The attacker needs to mount an active attack using equipment offering base station functionality. </p><p>Authentication is a crucial aspect of a wireless communication system due to the nature of the medium used, i e the radio link that is available to every one and not only the legitimate entities. Even the authentication mechanisms are attacked. It is possible to clone a subscription either by having physical access to the smart card or over the air interface. Cloning a subscription over the air requires base station functionality. </p><p>The most obvious threat against communication systems is eavesdropping on conversations. The privacy of GSM conversations is protected using some version of the A5 algorithm. There are several impressive cryptanalytical attacks against these algorithms, that break the encryption and make it possible to eavesdrop in real-time. Most of these algorithms require, however, extensive computation power and unrealistic quantities of known plaintext, which make it difficult to use them in practice. Difficulties using cryptanalytical attacks to break the confidentiality of GSM calls does not mean that conversations are well protected. Loopholes in the protocols used in GSM make it possible for an outsider, with access to sufficient equipment, to eavesdrop on conversations in real-time. </p><p>In the presence of these threats and vulnerabilities it is justified to wonder whether GSM provides sufficient security for users with very valuable information to communicate. These users may be military organisations, senior management personnel in large companies etc. GSM’s current security model does note provide sufficient protection for these entities. An additional layer of security should be added to the current security model.</p>

<p>This thesis investigates architectures for multiplying elements in Galois rings of the size 4^m, where m is an integer. </p><p>The main question is whether known architectures for multiplying in Galois fields can be used for Galois rings also, with small modifications, and the answer to that question is that they can. </p><p>Different representations for elements in Galois rings are also explored, and the performance of multipliers for the different representations is investigated.</p>

<p>Due to the development towards more dense programmable devices (FPGAs) it is today possible to fit a complete embedded system including microprocessor, bus architecture, memory, and custom peripherals onto one single reprogrammable chip, it is called a System-on-Chip (SoC). The custom peripherals can be of literally any nature from I/O interfaces to Ethernet Media Access Controllers. The latter core, however, usually consumes a big part of a good sized FPGA. The purpose of this thesis is to explore the possibilities of interfacing an FPGA based Microblaze system to an off-chip Ethernet MAC/PHY. A solution which would consume a smaller part of the targeted FPGA, and thus giving room for other on-chip peripherals or enable the use of a smaller sized FPGA. To employ a smaller FPGA is desirable since it would reduce power consumption and device price. This work includes evaluation of different available Ethernet devices, decision of interface technology, implementation of the interface, testing and verification. Since the ISA interface still is a common interface to Ethernet MAC devices a bus bridge is implemented linking the internal On-Chip Peripheral Bus (OPB) with the ISA bus. Due to delivery delays of the selected Ethernet chip a small on-chip ISA peripheral was constructed to provide a tool for the testing and verification of the bus bridge. The main result of this work is an OPB to ISA bus bridge core. The bridge was determined to work according to specification, and with this report at hand the connection of the Ethernet chip to the system should be quite straightforward.</p>

<p>This thesis investigates techniques for stealth hydroacoustic communication using spread spectrum. The Swedish naval defense organisations have a vision that all their units should be able to communicate with each other, even between underwater vehicles. But the properties of water makes it a complex channel to use for wireless communications. Radiomagnetic waves have very limited range in water, therefore acoustic waves are used. </p><p>In this report the basics of wireless communication systems are described including source coding, channel coding, modulation techniques as well as different techniques for spread spectrum. The fundamental principle for all spread spectrum systems is to use more bandwidth than necessary to spread the signal energy in the frequency spectrum. This limits the data rate but results in a robust communication link which is difficult to detect, intercept and to jam. </p><p>In addition to the theoretical background, this thesis also gives a brief description of a Matlab system and a VHDL-system that was developed during the project. Finally the results of this project are presented and some suggestions of further developments are given.</p>

<p>This thesis describes the design of fast JPEG processing accelerators for a DSP processor. </p><p>Certain computation tasks are moved from the DSP processor to hardware accelerators. The accelerators are slave co processing machines and are controlled via a new instruction set. The clock cycle and power consumption is reduced by utilizing the custom built hardware. The hardware can perform the tasks in fewer clock cycles and several tasks can run in parallel. This will reduce the total number of clock cycles needed. </p><p>First a decoder and an encoder were implemented in DSP assembler. The cycle consumption of the parts was measured and from this the hardware/software partitioning was done. Behavioral models of the accelerators were then written in C++ and the assembly code was modified to work with the new hardware. Finally, the accelerators were implemented using Verilog. </p><p>Extension of the accelerator instructions was given following a custom design flow.</p>

<p>In this thesis, a new way of using predisortion for linearization of power amplifiers is evaluated. In order to achieve an adequate power level for the jamming signal, power amplifiers are used in military jamming systems. Due to the nonlinear characteristic of the power amplifier, distortion will be present at the output. As a consequence, unwanted frequencies are subject to jamming. To decrease the distortion, linearization of the power amplifier is necessary. </p><p>In the system of interest, a portion of the distorted power amplifier output signal is fed back. Using this measurement, a predistortion signal is synthesized to allow suppression of the unwanted frequency components. The predistortion signal is updated a number of times in order to achieve a good outcome. Simulations are carried out in Matlab for testing of the algorithm. </p><p>The evaluation of the new linearization technique shows promising results and that good suppression of distortion components is achieved. Furthermore, new predistortion features are possible to implement, such as predistorsion in selected frequency bands. However, real hardware testing needs to be carried out to confirm the results.</p>