Hassan M. Elkamchouchi

Design and prototype implementation of SMS based home automation system

This research aims to design and implement a cost effective but yet flexible, adaptable, and secure Home automation system. Paper presents design and prototype implementation of a basic home automation system based on SMS technology. The proposed system consists of two main components; the GSM modem, which is the communication interface between the home automation system and the user. GSM modem uses SMS technology to exchange data, and signaling between users and home automation system. The second module is the micro controller, which is the core of the home automation system, and acts as the bridge between the GSM network (the user) and sensors and actuators of home automation system. Sensors and actuators are directly connected to hardware micro controller through appropriate interface. System supports a wide range of home automation devices; power management components, security, multimedia applications, and telecommunication devices. System security based on user authentication of each SMS being exchange, as each SMS contains user name and password (beside comments). User can easily configure home automation system setting through RS232 protocol using a user friendly interface.

Cellular Radio Network Planning using Particle Swarm Optimization

The cell planning problem concerns finding a set of sites for antennas from a set of pre-defined candidate sites, and for each selected site, to determine the number of antennas, as well as the associated values for each of the antenna parameters. All these choices must optimize a set of objectives. This paper presents a new approach for tackling this complex and highly combinatorial problem. The proposed approach is based on the application of the powerful optimization technique known as particle swarm optimization (PSO). First, the working area is represented by a suitable model showing topological and morphological information and the places for the candidate sites. After that, a solution representation is proposed converting each network plan to a bit stream. Finally, we apply the PSO algorithm to reach the best network plan satisfying our objectives. To validate the approach, computational results are presented using realistic data designing a cellular radio network in a part of Libreville, the capital of Gabon.

Square loop antenna miniaturization using fractal geometry

Antenna design is a very tricky problem. Common designs are sensitive to only a narrow range of frequencies, and are not efficient if they are smaller than a quarter of the wavelength. This is a problem for small, portable antennas, such as those on cellular phones. Fractal antenna designs can overcome some of these problems. Experiments have shown that antennas built with only a small number of iterations of a fractal process can exhibit sensitivity at several frequencies. As the number of iterations increases, the lowest frequency of the antenna gets lower, and additional higher frequencies are added. Also, fractal antennas can operate efficiently at one-quarter the size of more traditional designs. Properly harnessed, these features represent real advantages. Fractals already are being used for compact, multifrequency antennas in cellular phones and military communications hardware. Fractal Antennas are now used in cellular phone antenna fitting inside the body of the phone, and, the multifrequency aspect of the antenna will allow GPS to be incorporated in the phone. Other applications include compact, multifrequency wireless LAN and maritime antennas. In this paper we present a miniaturization model of a square loop antenna using a non-return to zero pulse as a generator instead of the square pulse in Minkowski fractal model that allows an increase in the total electric length without occupying more space. This led to an easily matched compact loop antenna, but with a small sacrifice of the gain.Antenna design is a very tricky problem. Common designs are sensitive to only a narrow range of frequencies, and are not efficient if they are smaller that a quarter of the wavelength. This is a problem for small, portable antennas, such as those on cellular phones. Fractal antenna designs can overcome some of these problems. Experiments have shown that antennas built with only a small number of iterations of a fractal process can exhibit sensitivity at several frequencies. As the number of iterations increases, the lowest frequency of the antenna gets lower, and additional higher frequencies are added. Also, fractal antennas can operate efficiently at one-quarter the size of more traditional designs. Properly harnessed, these features represent real advantages. Fractals already are being used for compact, multifrequency antennas in cellular phones and military communications hardware. Fractal antennas are now used in cellular phone antenna fitting inside the body of the phone, and the multifrequency aspect of the antenna will allow GPS to be incorporated in the phone. Other applications include compact, multifrequency wireless LAN and maritime antennas. In this paper we present a miniaturization model of a square loop antenna using a non-return to zero pulse as a generator instead of the square pulse in Minkowski fractal model that allows an increase in the total electric length without occupying more space. This led to an easy matched compact loop antenna, but with a small sacrifice of the gain.

Mobile one-time passwords: two-factor authentication using mobile phones

Static password authentication has security drawbacks. In two-factor authentication (2FA,) each user carries a device, called token, to generate passwords that are valid only one time. 2FA based on one-time passwords (OTPs) provides improved protection because users are prompted to provide something they know (i.e., PIN) and something they have (i.e., token). Many systems have satisfied the 2FA requirements by sending an OTP through an SMS to the users phone device. Unfortunately, international roaming, and SMS costs, delays, and security put restrictions on this system reliability. Also, time synchronous-based solutions are not applicable for mobile phones. In this paper, we present a novel 2FA scheme whereby multiple OTPs are being produced by utilizing an initial seed and two different nested hash chains: one dedicated to seed updating and the other used for OTP production. We overcome all the restrictions that come from other techniques. We analyze our proposal from the viewpoint of security and performance compared with the other algorithms. Copyright

The S-shaped dipole antenna

A new wire antenna is proposed namely the S-shaped dipole antenna. The radiation characteristics are obtained using the method of moments (MoM) with one-volt delta gap source and suitable dimensions for this antenna. From the obtained characteristics the antenna is considered of wide bandwidth. The given discussions proved the feasibility of using such antenna in a wide range of applications in the VHF and UHF frequency ranges both in free space and with a perfectly conducting ground plane. The proposed S-shaped antenna radiates left elliptically polarized (LEP) waves. Right elliptically polarized (REP) waves are obtained using the inverted S-shaped dipole antenna. Also circular polarization of both senses is obtained using the turnstile arrangement.

A new constrained fast null steering algorithm

A new algorithm is presented based on the constrained fast null steering algorithm. The structure of this new algorithm is simplified compared with that of the tree structure of the constrained fast null steering. A multiplier which is inserted in the structure, multiplies the output of any summing points with the main output. The function of the multiplier is to transfer a zero when occurring at any summing points to the main output. Numerical evaluation proved the validity and simplicity of this algorithm using 3, 4, and 5 elements array.

A New Secure Hash Dynamic Structure Algorithm (SHDSA) for Public Key Digital Signature Schemes

This paper presents a new secure hash algorithm based on dynamic structure algorithm called secure hash dynamic structure algorithm (SHDSA). It uses a famous secure hash algorithm (SHA) given by the National Institute of Standards and Technology (NIST). All NIST SHA have fixed structure, fixed constant and fixed output length. The goal of the new Advanced Encryption Standard (AES) is to offer, at its three cryptovariable size, 128, 192 and 256 bits of security, is the need for companion hash algorithms which provide similar levels of enhanced security. The basic design of SHDSA is to have variable output length of 128,192 and 256 bits, variable number of compression functions (single, double), variable number of iterations in each compression function and variable compression function structure. With this dynamic structure, it can provide many choices for practical applications with different level of security. The SHDSA has been designed to satisfy the dynamic structure algorithm with different level of enhanced security and to resist the advanced SHA attacks. The security analysis of the SFIDSA is compared to the old SHA given by the NIST and it gives more security and excellent results as shown in our discussion. In this paper, the digital signature standard algorithm (DSSA) which is given by the NIST has been modified using the proposed SHDSA. The SHDSA can be used in many applications such as, public key cryptosystems, digital signature, digital signcryption, message authentication code and random number generators

Dynamically key-controlled symmetric block cipher KAMFEE

This paper gives a new symmetric cryptosystem having a key dependent block length and key dependent rounds, enhanced by a rotor. The number of rotors wheels depends on key length too, rotor is implemented using successive eight bits affine transformation. Its block is divided into basic blocks of thirty-two bits length. 2/sup 32/ modulo addition and thirty-two bits XORING are used. It uses thirty-two bits s-boxes implemented using thirty-two affine transformation. Two steps of permutation are used, first step is basic block permutation and second step is basic block mixing. The strength of this system is compared with the well-known DES, GOST, BLOW FISH, IDEA, RC5 and RIJNDAEL and gives excellent results from the point of view of security characteristics and the statistics of the ciphertext. So authors suggest using KAMFEE in the area of banking and electronic fund transfer.

A deterministic approach for 2D-DOA estimation based on a V-shaped array and a virtual array concept

The problem of estimating both the azimuth and elevation angles associated with narrow band plane waves using antenna arrays is comprehensively studied by many researchers. Various array structures have been investigated; however, L-shaped arrays that consist of two independent uniform linear arrays at right angle to each other are proved to be the simplest structure. Pair-matching between the estimated directions by each ULA represents the main challenging problem. In this paper, a 2D-array with a V-shape structure, which is suitable for 120 degrees sectorized cellular systems, is proposed. A completely deterministic approach for solving the pair-matching problem based on a virtual array concept is presented.

New public key techniques based on double discrete logarithm problem

This paper introduces three new public key algorithms . The main one-way trapdoor functions of these algorithms are the double discrete logarithm problem (DDLP) and the integer factorization problem (IFP).The first proposed algorithm depends on the DDLP while the second and third proposed algorithms depend simultaneously on both the DDLP and the IFP. The validity of these algorithms is proven by applying to messages that are either an integer or a text and returning the original message in various numerical examples. The proposed cryptosystems have many advantages that are explained in details.