In this paper, we analyze the Akleylek, et al. scheme and their try to enhance a security of peer-to-peer network by merging ElGamal scheme with knapsack system. We demonstrate that this combination disclose a security and causes a scheme weak to cipher-text only attack. So, in a network a hacker can use this attack and easily decrypt an encrypted message. Also, we illustrate that a receiver cannot recover an encrypted message in polynomial time. Thus, this scheme is entirely inappropriate to employ in the peer-to-peer networks. We will change this scheme to enhance security and efficiency.

The construction of optimal linear block error-correcting codes is not an easy problem, for this, many studies describe methods for generating good error correcting codes in terms of minimum distance. In a previous work, we have presented the multiple impulse method (MIM) to evaluate the minimum distance of linear codes. In this paper we will present an optimization of the MIM method by genetic algorithms, and we found many new optimal Double and Triple Circulant Codes (DCC & TCC) with the highest known parameters using the MIM method as an evaluator of the minimum distance. Two approaches are used in the exploration of the space of generators; the first is based on genetic algorithms, however the second is on the random search algorithm.

The places where you can find fractals include almost every part of the universe, from bacteria cultures to galaxies to your body. Many natural surfaces have a statistical quality of roughness and self-similarity at different scales. Mandelbrot proposed fractal geometry and is the first one to notice its existence in the natural world. Fractals have become popular recently in computer graphics for generating realistic looking textured images. This paper presents a brief introduction to fractals along with its main features and generation techniques. The concentration is on the fractal texture and the measures to express the texture of fractals.

Memory management on which researchers are mainly focusing are the different techniques related to memory management i.e. garbage collection techniques, scheduling, real time system, user oriented design and many more. The major problem found out in memory management is processor and operating system delays. Here a new design of processor is discussed in the paper that will improve to the over all system performance.