## Search

Now showing items 21-30 of 94

#### High Performance Elliptic Curve Cryptographic Co-processor

(University of Waterloo, 2003)

In FIPS 186-2, NIST recommends several finite fields to be used in the elliptic curve digital signature algorithm (ECDSA). Of the ten recommended finite fields, five are binary extension fields with degrees ranging ...

#### Multi-interface Multi-channel wireless mesh networks

(University of Waterloo, 2004)

In this thesis we propose a multi-channel wireless network based on nodes that use multiple 802. 11 radio interfaces. The proposed system is singular, as it does not require new hardware or a new MAC, but instead ...

#### Convex Optimization and Utility Theory: New Trends in VLSI Circuit Layout

(University of Waterloo, 1999)

The design of modern integrated circuits is overwhelmingly complicated due to the enormous number of cells in a typical modern circuit. To deal with this difficulty, the design procedure is broken down into a set of ...

#### A Lightweight Processor Core for Application Specific Acceleration

(University of Waterloo, 2004)

Advances in configurable logic technology have permitted the development of low-cost, high-speed configurable devices, allowing one or more soft processor cores to be introduced into a configurable computing system. ...

#### Foveated Sampling Architectures for CMOS Image Sensors

(University of Waterloo, 2005)

Electronic imaging technologies are faced with the challenge of power consumption when transmitting large amounts of image data from the acquisition imager to the display or processing devices. This is especially a concern ...

#### Issues in Implementation of Public Key Cryptosystems

(University of Waterloo, 2006)

A new class of moduli called the low-weight polynomial form integers (LWPFIs) is introduced. LWPFIs are expressed in a low-weight, monic polynomial form,

**p**=**f**(**t**). While the generalized Mersenne numbers (GMNs) proposed by Solinas allow only powers of two for**t**, LWPFIs allow any positive integers. In our first proposal of LWPFIs, we limit the coefficients of**f**(**t**) to be 0 and ±1, but later we extend LWPFIs to allow any integer of less than**t**for the coefficients of**f**(**t**). Modular multiplication using LWPFIs is performed in two phases: 1) polynomial multiplication in Z[**t**]/**f**(**t**) and 2) coefficient reduction. We present an efficient coefficient reduction algorithm based on a division algorithm derived from the Barrett reduction algorithm. We also show a coefficient reduction algorithm based on the Montgomery reduction algorithm. We give analysis and experimental results on modular multiplication using LWPFIs. <br /><br /> New three, four and five-way squaring formulae based on the Toom-Cook multiplication algorithm are presented. All previously known squaring algorithms are symmetric in the sense that the point-wise multiplication step involves only squarings. However, our squaring algorithms are asymmetric and use at least one multiplication in the point-wise multiplication step. Since squaring can be performed faster than multiplication, our asymmetric squaring algorithms are not expected to be faster than other symmetric squaring algorithms for large operand sizes. However, our algorithms have much less overhead and do not require any nontrivial divisions. Hence, for moderately small and medium size operands, our algorithms can potentially be faster than other squaring algorithms. Experimental results confirm that one of our three-way squaring algorithms outperforms the squaring function in GNU multiprecision library (GMP) v4. 2. 1 for certain range of input size. Moreover, for degree-two squaring in Z[**x**], our algorithms are much faster than any other squaring algorithms for small operands. <br /><br /> We present a side channel attack on XTR cryptosystems. We analyze the statistical behavior of simultaneous XTR double exponentiation algorithm and determine what information to gather to reconstruct the two input exponents. Our analysis and experimental results show that it takes**U**<sup>1. 25</sup> tries, where**U**= max(**a**,**b**) on average to find the correct exponent pair (**a**,**b**). Using this result, we conclude that an adversary is expected to make**U**<sup>0. 625</sup> tries on average until he/she finds the correct secret key used in XTR single exponentiation algorithm, which is based on the simultaneous XTR double exponentiation algorithm....#### Channel Estimation and Equalization for Cooperative Communication

(University of Waterloo, 2006)

The revolutionary concept of space-time coding introduced in the last decade has demonstrated that the deployment of multiple antennas at the transmitter allows for simultaneous increase in throughput and reliability because ...

#### An Analysis of Wireless High-speed Data Services for Cellular CDMA Systems

(University of Waterloo, 2002)

The interest in the development of wireless high-speed data services is in response to the strong market demand for high-speed wireless Internet access. Current standards aim at delivering a peak data rate greater than ...

#### A Scalable, Secure, and Energy-Efficient Image Representation for Wireless Systems

(University of Waterloo, 2004)

The recent growth in wireless communications presents a new challenge to multimedia communications. Digital image transmission is a very common form of multimedia communication. Due to limited bandwidth and broadcast ...

#### Design of a MOSFET-Based Pulsed Power Supply for Electroporation

(University of Waterloo, 2006)

The use of high-voltage pulsed electric fields in biotechnology and medicine has lead to new methods of cancer treatment, gene therapy, drug delivery, and non-thermal inactivation of microorganisms. Regardless of the application, the objective is to open pores in the cell membrane and hence either facilitate the delivery of foreign materials inside the cell or to kill the cell completely. Pulsed power supplies are needed for electroporation, which is the process of applying pulsed electric fields to biological cells to induce a temporary permeability in the cell membrane. The applications of pulsed electric fields are dependent on the output pulse shape and pulse parameters, both of which can be affected by the circuit parameters of the pulsed power supply and the conductivity of the media being treated. <br /><br /> In this research, two Metal Oxide Field Effect Transistor (MOSFET)-based pulsed power supplies that are used for electroporation experiments were designed and built. The first used up to three MOSFETs in parallel to deliver high voltage pulses to highly conductive loads. To produce pulses with higher voltages, a second pulsed power supply using two MOSFETs connected in series was designed and built. The parallel and series MOSFET-based pulsed power supplies are capable of producing controllable square pulses with widths of a few hundred nanoseconds to dc and amplitudes up to 1500 V and 3000 V, respectively. The load in this study is a 1-mm electroporation cuvette filled with a buffer solution that is varied in conductivity from 0. 7 mS/m to 1000 mS/m. The results indicate that by controlling the circuit parameters such as the number of parallel MOSFETs, gate resistance, energy storage capacitance, and the parameters of the MOSFET driver gating pulses, the output pulse parameters can be made almost independent of the load conductivity. <br /><br /> Using the pulsed power supplies designed in this work, an investigation into electroporation-mediated delivery of a plasmid DNA molecule into the pathogenic bacterium

**E. coli**O157:H7, was conducted. It was concluded that increasing the electric field strength and pulse amplitude resulted in an increase in the number of transformants. However, increasing the number of pulses had the effect of reducing the number of transformants. In all of the experiments the number of cells that were inactivated by the exposure to the pulsed electric field was measured....