Ali Makki Sagheer

RC4-2S: RC4 Stream Cipher with Two State Tables

One of the most important symmetric cryptographic algorithms is Rivest Cipher 4 (RC4) stream cipher which can be applied to many security applications in real time security. However, RC4 cipher shows some weaknesses including a correlation problem between the public known outputs of the internal state. We propose RC4 stream cipher with two state tables (RC4-2S) as an enhancement to RC4. RC4-2S stream cipher system solves the correlation problem between the public known outputs of the internal state using permutation between state 1 (S 1 ) and state 2 (S 2 ). Furthermore, key generation time of the RC4-2S is faster than that of the original RC4 due to less number of operations per a key generation required by the former. The experimental results confirm that the output streams generated by the RC4-2S are more random than that generated by RC4 while requiring less time than RC4. Moreover, RC4-2S’s high resistivity protects against many attacks vulnerable to RC4 and solves several weaknesses of RC4 such as distinguishing attack.

Proposing of Developed Advance Encryption Standard

This paper presents a variant of Advance Encryption Standard (AES) cipher that is depending on the same structure of the original AES Substitution Permutation Network (SPN) and the same mathematical background represented by Galois Field (GF28). The proposed cipher encrypt and decrypt data with block size of 512-bit and with key size of 128-bit expanded into 512-bits which means encrypt block that four times larger than the block of the original cipher and provide high margin of security with key size 128-bit of key needs 2512 possibility instead of 2128, since this cipher is based on two perfect techniques for the expansion and generating key reaching to 512-bit for each round. This cipher depends upon strong mathematical foundations and solid algebraic representation and introduces deeper insights in developing AES.

Improvement of scatter search using Bees Algorithm

The Scatter Search is one of the population-based metaheuristics, which can be used to solve a wide range of problems including Traveling Salesman Problem (TSP), Routing Protocol, and End-to-End QoS , while Bees Algorithm can be applied to optimize the solution of these problems. In this paper, an improved Scatter Search algorithm based on Bees Algorithm has been presented. The improvement provides Scatter Search with random exploration for search space of problem and more of intensification for promising solutions. The original and improved Scatter Search has been tested on Traveling Salesman Problem. A computational experiment with benchmark instances is reported. The results demonstrate that the improved Scatter Search algorithm produces better performance than original Scatter Search algorithm. The developed algorithm has been compared with other algorithms for the same problem, and the result was competitive with some algorithm and insufficient with another.

Video Encryption Based on Special Huffman Coding and Rabbit Stream Cipher

In this paper a two Special Huffman Tree (SHT) algorithms have been designed and implemented to be encoded with an MPEG video file instead of the standard Huffman tree algorithm. The first SHT has been built with 89-entries, and the other with 100-entries. The SHTs are encrypted using part of the key-stream generated by Rabbit algorithm. The other part of the key-stream is used in insertion operation. In this latter operation, a number of bits of the key-stream are inserted in the coded desired file. The encrypted SHTs with the encoded desired file are sent to the receiver, so no one knows the tree used to encode the file except the sender and the receiver. Many types of tests and measurements (such as efficiency, compression, speed, and security measurements) have been performed to evaluate the performance of this algorithm. Calculation of the compression efficiency of SHTs has been found to be higher than that of the standard Huffman tree. Also, it has been shown that the increasing ratio in size of the generated file to that of the original file is very small and can be neglected.

Ensure Security of Compressed Data Transmission

Data compression offers an attractive approach to reducing communication costs using available bandwidth effectively. It makes sense to pursue research on developing algorithms that can most effectively use available network. It is also important to consider the security aspect of the data being transmitted is vulnerable to attacks. The basic aim of this work is to develop a module for combining the operation of compression and encryption on the same set of data to perform these two operations simultaneously. This is achieved through embedding encryption into compression algorithms since both cryptographic ciphers and entropy coders bear certain resemblance in the sense of secrecy. First in the secure compression module, the given text is preprocessed and transform of into some intermediate form which can be compressed with better efficiency and security. This solves some problems relevant to the common encryption methods which generally manipulate an entire data set, most encryption algorithms tend to make the transfer of information more costly in terms of time and sometimes bandwidth.

RC4 Stream Cipher with a Random Initial State

Rivest Cipher 4 (RC4) is one of the modern encryption techniques utilized in many real time security applications; however, it has several weaknesses including a correlation problem in the initially generated key sequences. In this paper, we propose RC4 stream cipher with a random initial state (RRC4) to solve the RC4’s correlation problem between the public known outputs of the internal state. RRC4 solves the weak keys problem of the RC4 using random initialization of internal state S. Experimental results show that the output streams generated by RRC4 are more random than that generated by RC4. Moreover, RRC4’s high resistivity protects against many attacks vulnerable to RC4 and solves several weaknesses of RC4 such as predictable first bytes of intermediate outputs by RC4.

Identity Based Cryptography for secure AODV routing protocol

Mobile Ad hoc Network (MANET) is crowd of mobile node communicates and participate in network operation unused to fixed base station each node depended on the other node to deliver the packet that send from source node to destination. Ad hoc network needed secure routing protocols to protect network from many threat in its environment, In this paper we used Identity Based Cryptography (IBC) that have many advantage compared to traditional cryptosystems for Secure AODV (Ad hoc On demand Distance Vector routing) routing protocol.

Elliptic curves cryptographic techniques

The security issues are very important for information technology applications now a day such as ATM and Smart cards. One of the recent public key cryptosystems is Elliptic Curves Cryptography. The group of the elliptic curve points forms an Abelian group, that is a suitable choice for constructing the Elliptic Curve Discrete Logarithm Problem (ECDLP). This led to create cipher system based on the difficulty of its solution. That is open a new windows for treatment with special groups and new operations. This paper provides three proposed techniques as a modification of ElGamal cryptosystem based on the elliptic curves, as well as, implement these techniques, compute the computational complexity of these methods compared to the original methods, compare these methods with the original methods in running time of several messages have different sizes. A great reduction in calculation time is resulted, also these techniques makes the cipher text more confused than cipher text which resulted from original techniques.

Enhancing Security and Speed of RC4

Wireless communication security is a critical factor for secure communication among large scale of wireless networks. A limited resource constraint, such as power and memory size presents a significant challenge to implement existing cryptographic algorithms. One of the most important symmetric cryptographic algorithms is Rivest Cipher 4 (RC4) stream cipherthatis utilized in many real-time security applications. However, the RC4 cipher shows some weaknesses, including a correlation problem between the public known outputs of the internal state. In this paper, we propose RC4 stream cipher with a random initial state (RRC4) to solve the weak keys problem of the RC4 using a random initialization of internal state S. We also propose RC4 stream cipher with two state tables (RC4-2S) to solve the correlation problem between the public known outputs of the internal state using permutation between state1 (S1) and state 2 (S2) while requiring less time than RC4. Finally, we propose RC4 stream cipher with two state tables togenerate four keys (RC4-2S) in each cycle which further enhances randomness overRC4-2S and RRC4.

Visual Cryptography Technique Based on FFT

Visual cryptography is a powerful approach for image sharing security through unsecured network such as Internet. Pixel expansion and bad image quality are the most cons of this approach. Therefore, visual cryptographic technique is proposed for grayscale images to overcome these drawbacks by Fast Fourier Transform (FFT). FFT is used for image sharing where each share is encrypted via Multilayer Security Method (MSM). Image compression is also basically used to eliminate the pixel expansion which is produced before the encryption process. The experimental results and security analysis state that the proposed visual cryptographic technique leads to active levels of image security and quality without pixel expansion.