International Journal of Mobile Computing and Multimedia Communications: Guest editorial preface

Analysis of the effect of different parameters of the RC4 encryption algorithm where examined. Some experimental work was performed to illustrate the performance of this algorithm based on changing some of these parameters. The execution time as a function of the encryption key length and the file size was examined; this has been stated as complexity and security. Various data types were analyzed and the role of the data type was also emphasized. The results have been analyzed and interpreted as mathematical equations showing the relationship between the examined data and hence can be used to predict any future performance of the algorithm under different conditions. The order of the polynomial to approximate the execution time was justified.

Evaluation of the RC4 Algorithm for Data Encryption.

This paper presents an online highly accurate system for automatic number plate recognition (ANPR) that can be used as a basis for many real-world ITS applications. The system is designed to deal with unclear vehicle plates, variations in weather and lighting conditions, different traffic situations, and high-speed vehicles. This paper addresses various issues by presenting proper hardware platforms along with real-time, robust, and innovative algorithms. We have collected huge and highly inclusive data sets of Persian license plates for evaluations, comparisons, and improvement of various involved algorithms. The data sets include images that were captured from crossroads, streets, and highways, in day and night, various weather conditions, and different plate clarities. Over these data sets, our system achieves 98.7%, 99.2%, and 97.6% accuracies for plate detection, character segmentation, and plate recognition, respectively. The false alarm rate in plate detection is less than 0.5%. The overall accuracy on the dirty plates portion of our data sets is 91.4%. Our ANPR system has been installed in several locations and has been tested extensively for more than a year. The proposed algorithms for each part of the system are highly robust to lighting changes, size variations, plate clarity, and plate skewness. The system is also independent of the number of plates in captured images. This system has been also tested on three other Iranian data sets and has achieved 100% accuracy in both detection and recognition parts. To show that our ANPR is not language dependent, we have tested our system on available English plates data set and achieved 97% overall accuracy.

Accurate Detection and Recognition of Dirty Vehicle Plate Numbers for High-Speed Applications

Security of data/images is one of the crucial aspects in the gigantic and still expanding domain of digital transfer. Encryption of images is one of the well known mechanisms to preserve confidentiality of images over a reliable unrestricted public media. This medium is vulnerable to attacks and hence efficient encryption algorithms are necessity for secure data transfer. Various techniques have been proposed in literature till date, each have an edge over the other, to catch-up to the ever growing need of security. This paper is an effort to compare the most popular techniques available on the basis of various performance metrics like differential, statistical and quantitative attacks analysis. To measure the efficacy, all the modern and grown-up techniques are implemented in MATLAB-2015. The results show that the chaotic schemes used in the study provide highly scrambled encrypted images having uniform histogram distribution. In addition, the encrypted images provided very less degree of correlation coefficient values in horizontal, vertical and diagonal directions, proving their resistance against statistical attacks. In addition, these schemes are able to resist differential attacks as these showed a high sensitivity for the initial conditions, i.e. pixel and key values. Finally, the schemes provide a large key spacing, hence can resist the brute force attacks, and provided a very less computational time for image encryption/decryption in comparison to other schemes available in literature.

A Survey of Image Encryption Algorithms

In asymmetric key cryptography, also called Public Key cryptography, two different keys (which forms a key pair) are used. One key is used for encryption & only the other corresponding key must be used for decryption. No other key can decrypt the message, not even the original (i.e. the first) key used for encryption. The beauty of this scheme is that every communicating party needs just a key pair for communicating with any number of other communicating parties. Once some one obtains a key pair, he /she can communicate with any one else. RSA is a well known public-key cryptography algorithm. It is the first algorithm known to be suitable for signing as well as encryption, and was one of the first great advances in public key cryptography. The security of the RSA cryptosystem is based on two mathematical problems: the problem of factoring large numbers know mathematical attack and the problem of trying all possible private keys know brute force attack. So to improve the security, this scheme presents a new cryptography algorithm based on additive homomorphic properties called Modified RSA Encryption Algorithm (MREA). MREA is secure as compared to RSA as it is based on the factoring problem as well as decisional composite residuosity assumptions which is the intractability hypothesis. The scheme is an additive homomorphic cryptosystem, this means that, given only the public-key and the encryption of m1 and m2, one can compute the encryption of m1 + m2. This scheme also presents comparison between RSA and MREA cryptosystems in terms of security and performance.

Modified RSA Encryption Algorithm (MREA)

As the mobile telecommunication systems are tremendously growing allover the world then the numbers of handheld and base stations are also rapidly growing and it became very popular to see these base stations distributed everywhere in the neighborhood and on roof tops which has caused a considerable amount of panic to the public in Palestine concerning wither the radiated electromagnetic field from these base stations may cause any health effect or hazard. This paper focuses on the radiated electromagnetic energy from some typical mobile base stations around the city of Nablus. The exposure levels due to these stations were measured and compared to some international standard guidelines like ICNIRP and FCC to see if it meets these standards, this is in order to answer some of the public fear and concern. The results are presented and some comments are made on the other sources of electromagnetic radiation in the 200 kHz to 3 GHz range.

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Electromagnetic Radiation Measurements and Safety Issues of some Cellular Base Stations in Nablus

Voice changing has many applications in the industry and commercial filed. This paper emphasizes voice conversion using a pitch shifting method which depends on detecting the pitch of the signal (fundamental frequency) using Simplified Inverse Filter Tracking (SIFT) and changing it according to the target pitch period using time stretching with Pitch Synchronous Over Lap Add Algorithm (PSOLA), then resampling the signal in order to have the same play rate. The same study was performed to see the effect of voice conversion when some Arabic speech signal is considered. Treatment of certain Arabic voiced vowels and the conversion between male and female speech has shown some expansion or compression in the resulting speech. Comparison in terms of pitch shifting is presented here. Analysis was performed for a single frame and a full segmentation of speech. K e y w o r d s: voice changing, PSOLA, pitch shifting, resampling, SIFT

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Voice conversion using pitch shifting algorithm by time stretching with psola and re-sampling

Vehicle plate recognition is an effective image processing technique used to identify vehicles' plate numbers. There are several applications for this technique which expand through many fields and interest groups. Vehicle plate recognition may be used as a marketing tool, for purposes of traffic and border control, for law enforcement, and travel. Many methods have been proposed to facilitate this technique. This study proposes an edgedetection method to enable a Plate Recognition System through practical situations, such as various environmental or meteorological conditions. Image processing tools are used to scan the plate area, resize it, and convert it toward a gray scale prior to filtering the image in order to remove small objects. The obtained objects are identified such that the numbers object is recognized. The details of the obtained image are controlled through the standard deviation of the Gaussian filter (sigma).

Canny Edge-Detection Based Vehicle Plate Recognition

Some of the important parameters of the blowfish encryption algorithm are being analyzed and examined to see how these parameters may affect the performance of the algorithm. The performance indices here are the security and speed of the algorithm. This study is applied to different types of data; text, sound and image. For each case the encryption/decryption key length has been changed and its effect on the performance was noticed. Moreover, the file size is changed and its affect on the performance of the algorithm was noticed. This has shown that changing the key length has no effect on the encryption or decryption time whereas changing the plaintext file size is directly reflected on the processing time. The results obtained here have been converted into modules of equations of high orders thus the future performance of the algorithm may be predicted from these equations

Allam Mousa

Papers

Evaluation of the RC4 Algorithm for Data Encryption.

Electromagnetic Radiation Measurements and Safety Issues of some Cellular Base Stations in Nablus

Voice conversion using pitch shifting algorithm by time stretching with psola and re-sampling

Canny Edge-Detection Based Vehicle Plate Recognition

Data encryption performance based on Blowfish