Cryptosystem designers frequently assume that secrets will be manipulated in closed, reliable computing environments. Unfortunately, actual computers and microchips leak information about the operations they process. This paper examines specific methods for analyzing power consumption measurements to find secret keys from tamper resistant devices. We also discuss approaches for building cryptosystems that can operate securely in existing hardware that leaks information.

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Differential Power Analysis

1 Introduction to Wavelets 2 A Multiresolution Formulation of Wavelet Systems 3 Filter Banks and the Discrete Wavelet Transform 4 Bases, Orthogonal Bases, Biorthogonal Bases, Frames, Tight Frames, and Unconditional Bases 5 The Scaling Function and Scaling Coefficients, Wavelet and Wavelet Coefficients 6 Regularity, Moments, and Wavelet System Design 7 Generalizations of the Basic Multiresolution Wavelet System 8 Filter Banks and Transmultiplexers 9 Calculation of the Discrete Wavelet Transform 10 Wavelet-Based Signal Processing and Applications 11 Summary Overview 12 References Bibliography Appendix A Derivations for Chapter 5 on Scaling Functions Appendix B Derivations for Section on Properties Appendix C Matlab Programs Index

Introduction to Wavelets and Wavelet Transforms: A Primer

In this paper, we develop the nonsubsampled contourlet transform (NSCT) and study its applications. The construction proposed in this paper is based on a nonsubsampled pyramid structure and nonsubsampled directional filter banks. The result is a flexible multiscale, multidirection, and shift-invariant image decomposition that can be efficiently implemented via the a trous algorithm. At the core of the proposed scheme is the nonseparable two-channel nonsubsampled filter bank (NSFB). We exploit the less stringent design condition of the NSFB to design filters that lead to a NSCT with better frequency selectivity and regularity when compared to the contourlet transform. We propose a design framework based on the mapping approach, that allows for a fast implementation based on a lifting or ladder structure, and only uses one-dimensional filtering in some cases. In addition, our design ensures that the corresponding frame elements are regular, symmetric, and the frame is close to a tight one. We assess the performance of the NSCT in image denoising and enhancement applications. In both applications the NSCT compares favorably to other existing methods in the literature

/pdf/the-nonsubsampled-contourlet-transform-theory-design-and-3a4lsit6lx.pdf

The Nonsubsampled Contourlet Transform: Theory, Design, and Applications

An intelligent automated assistant system engages with the user in an integrated, conversational manner using natural language dialog, and invokes external services when appropriate to obtain information or perform various actions. The system can be implemented using any of a number of different platforms, such as the web, email, smartphone, and the like, or any combination thereof. In one embodiment, the system is based on sets of interrelated domains and tasks, and employs additional functionally powered by external services with which the system can interact.

Intelligent Automated Assistant

Numerical Methods for Scientists and Engineers

A method and system for performing speech recognition for an internet appliance using a remotely located speech recognition application. The invention includes an internet appliance that is connected through a network with either a stand-alone computer or a server computer located at the Internet Service Provider. Verbal commands directed to an internet appliance are received as analog signals and converted to digital signals. The digital signals are remotely translated into a set of instructions by a dedicated hardware device or a software program that operates a speech recognition application at either a stand-alone computer or server computer located at an Internet Service Provider in a form recognizable by the internet appliance. The internet appliance receives and executes the translated instructions.

Method and system for performing speech recognition for an internet appliance using a remotely located speech recognition application

Primary user emulation attacks are a potential security threat to cognitive radio networks. In this work, we attempt to characterize an advanced primary user emulation attack and an advanced countermeasure against such an attack. Specifically, we show that both the attacker and the defender can apply estimation techniques and learning methods to obtain the key information of the environment and thus design better strategies. We further demonstrate that the advanced attack strategy can defeat the naive defense technique that focuses only on the received signal power, whereas the advanced defense strategy that exploits the invariant of communication channels can counteract the advanced attack effectively.

Modeling primary user emulation attacks and defenses in cognitive radio networks

Messages transmitted between a receiver (150) and a transmitter (240) are used to maximize a communication data rate. In particular, a multicarrier modulation system uses messages that are sent from the receiver to the transmitter to exchange one or more sets of optimized communication parameters. The transmitter then stores these communication parameters and when transmitting to that particular receiver, the transmitter utilizes the stored parameters in an effort to maximize the data rate to that receiver. Likewise, when the receiver receives packets from that particular transmitter, the receiver can utilize the stored communication parameters for reception.

Systems and methods for high rate ofdm communications

Typical forward error correction methods employ Trellis Code Modulation. By substituting low density parity check coding in place of the convolution code as part of a combined modulation and encoding procedure, low density parity check coding and modulation can be performed. The low density parity check codes have no error floor, no cycles, an equal bit error rate for the information bits and the parity bits, and timely construction of both a parity check matrix with variable codeword size and a generator matrix is possible.

Todor Cooklev

Papers

Method and system for performing speech recognition for an internet appliance using a remotely located speech recognition application

Modeling primary user emulation attacks and defenses in cognitive radio networks

Systems and methods for high rate ofdm communications

Systems and methods for LDPC coded modulation

Two Algorithms for Modular Exponentiation Using Nonstandard Arithmetics