A Modified and Secured RSA Public Key Cryptosystem Based on “n” Prime Numbers

Cryptography is the study that provides security service. It concerns with confidentiality, integrity, and authentication. Public key cryptography provides an enormous revolution in the field of the cryptosystem. It uses two different keys where keys are related in such a way that, the public key can use to encrypt the message and private key can be used to decrypt the message. This paper proposed an enhanced and modified approach of RSA cryptosystem based on “n” distinct prime number. This existence of “n” prime number increases the difficulty of the factoring of the variable “N” which increases the complexity of the algorithm. In this approach, two different public key and private key generated from the large factor of the variable “N” and perform a double encryption-decryption operation which affords more security. Experiment on a set of a random number provided that the key generation time, analysis of variable “N”, encryption and decryption will take a long time compared to traditional RSA. Thus, this approach is more efficient, highly secured and not easily breakable.

Handwritten Numeric and Alphabetic Character Recognition and Signature Verification Using Neural Network

Handwritten signature and character recognition has become challenging research topic due to its numerous applications. In this paper, we proposed a system that has three sub-systems. The three subsystems focus on offline recognition of handwritten English alphabetic characters (uppercase and lowercase), numeric characters (0 - 9) and individual signatures respectively. The system includes several stages like image preprocessing, the post-processing, the segmentation, the detection of the required amount of the character and signature, feature extraction and finally Neural Network recognition. At first, the scanned image is filtered after conversion of the scanned image into a gray image. Then image cropping method is applied to detect the signature. Then an accurate recognition is ensured by post-processing the cropped images. MATLAB has been used to design the system. The subsystems are then tested for several samples and the results are found satisfactory at about 97% success rate. The quality of the image plays a vital role as the images of poor or mediocre quality may lead to unsuccessful recognition and verification.

Design and Optimization of Photonic Crystal Fiber for Liquid Sensing Applications

This paper proposes a hexagonal photonic crystal fiber （H-PCF） structure with high relative sensitivity for liquid sensing; in which both core and cladding are microstructures. Numerical investigation is carried out by employing the full vectorial finite element method （FEM）. The analysis has been done in four stages of the proposed structure. The investigation shows that the proposed structure achieves higher relative sensitivity by increasing the diameter of the innermost ring air holes in the cladding. Moreover, placing a single channel instead of using a group of tiny channels increases the relative sensitivity effectively. Investigating the effects of different parameters, the optimized structure shows significantly higher relative sensitivity with a low confinement loss.

Design and Optimization of Photonic Crystal Fiber Based Sensor for Gas Condensate and Air Pollution Monitoring

In this paper, a hexagonal shape photonic crystal fiber （H-PCF） has been proposed as a gas sensor of which both micro-structured core and cladding are organized by circular air cavities. The reported H-PCF has a single layer circular core which is surrounded by a five-layer hexagonal cladding. The overall pretending process of the H-PCF is completed by using a full vectorial finite element method （FEM） with perfectly matched layer （PML） boundary condition. All geometrical parameters like diameters and pitches of both core and cladding regions have fluctuated with an optimized structure. After completing the numerical analysis, it is clearly visualized that the proposed H-PCF exhibits high sensitivity with low confinement loss. The investigated results reveal the relative sensitivity of 56.65% and confinement loss of 2.31×10^-5 dB/m at the 1.33%tm wavelength. Moreover, effective area, nonlinearity, and V-parameter of the suggested PCF are also briefly described.

A Study on Priority Based ZigBee Network Performance Analysis with Tree Routing Method

The Wireless Sensor Network (WSN) is spatially distributed autonomous sensor to sense special task. WSN like ZigBee network forms simple interconnecting, low power, and low processing capability wireless devices. The ZigBee devices facilitate numerous applications such as pervasive computing, security monitoring and control. ZigBee end devices collect sensing data and send them to ZigBee Coordinator. The Coordinator processes end device requests. The effect of a large number of random unsynchronized requests may degrade the overall network performance. An effective technique is particularly needed for synchronizing available node’s request processing to design a reliable ZigBee network. In this paper, region based priority mechanism is implemented to synchronize request with Tree Routing Method. Riverbed is used to simulate and analyze overall ZigBee network performance. The results show that the performance of the overall priority based ZigBee network model is better than without a priority based model. This research paves the way for further designing and modeling a large scale ZigBee network.

Mobility Issue on Octagonal Structured ZigBee Network Using Riverbed

Wireless Sensor Network (WSN) is a special type of communication medium through distributed sensor nodes. Popular wireless sensor nodes like ZigBee have splendid interoperability after IEEE 802.15.4 standardization in the domain of wireless personal area network (WPAN). ZigBee has another great feature mobility that makes the ZigBee network more versatile. The mobility feature of ZigBee mobile nodes has a greater impact on network performance than fixed nodes. This impact sometimes turns into more severe because of network structure and mobility model. This study mainly focuses on the performance analysis of the ZigBee mobile node under Random and Octagonal mobility management model with the Tree routing method. The Riverbed academic modeler is used to design, implement and simulate the ZigBee network under certain conditions. This study also presents a competitive performance analysis based on ZigBee mobile nodes transmitter and receiver characteristics under the observation of the mobility model. This indicates that Octagonal mobility model exhibits better performance than the Random mobility model. This study will constitute a new way for further designing and planning a reliable and efficient ZigBee network.

Single polarization photonic crystal fiber filter based on surface plasmon resonance

In this paper,we propose a photonic crystal fiber(PCF)polarization filter based on surface plasmon resonance(SPR)characteristics.Gold nanowire is used as the active plasmonic material.Light into silica core becomes coupled to gold nanowire stimulating SPR. It soplits light into two orthogonal(x-polarization and y-polarization)polarization in the second order of surface plasmon polarization.Numerical investigations of the proposed PCF filter is finite element method(FEM).By position,the performance of the propsed PCF filter is inspected rigorously.Filtering of any polarization can be obtained by properly placing the metal wires.The maximum cnfinement loss of x-polarization is 692.25dB/cm and y-polarization is 1.13dB/cm offers at resonance position 1.42μm.Such a confinement loss difference between two orthogonal polarizations makes PCF a talented candidate to filter devicees.Consequently,the recommended PCF structure is useful for polarization device.