Engineering and Technology Journal

Video encrypting is one technique to protect digital videos, it used to avoid unwanted interference and viewing of the transmitted videos. In this paper, a new selective video cryptography algorithm is suggested using light stream algorithm. As it known video size is large in size and it consume time in the encryption process, ChaCha a light encryption algorithm has been used to reduce the encryption time, encryption is done by Xoring frames of video with the key generated from ChaCha algorithm, it produced an acceptable results from robustness point view, but still encryption process consumed time, thus to speed up this process, feature detection operator (FAST) is used to encrypt key points result from FAST operator, in addition key points from this is increased to optimized between speed and robustness of proposed algorithm. In evaluation process, some of measuring quality factors MSE, PSNR, Correlation, NPCR, UACI and entropy are specified for evaluating and comparing between two suggested encryption algorithms which gave good result in encryption process (ChaCha and ChaCha with FAST Enhancement). Experimental results have discovered that the current projected has less encrypting time and better encrypting influence

Voice over Internet Protocol (VoIP) calls are susceptible to interfere at many points by many attackers, thus encryption considered an important part in keeping VoIP.
In this paper, Encryption VoIP based on Generated Biometric Key for RC4 Algorithm is proposed to encrypt the voice data before transmitting it over the network. The system uses a stream algorithm based on RC4 encryption with the new method of biometrics based Key generation technique. This system has generated complex keys in offline phase which is formed depend on features extracted using Linear Discernment Analysis (LDA) from face images.
The experimental work shows that the proposed system offers secrecy to speech data with voice cipher is unintelligible and the recovered voice has perfect quality with MSR equal to zero and PSNR equal to infinity.

Rivest Cipher 4 (RC4) is one of most common stream cipher, but it experience many problem, such as, there is little combination between the plaintext and cipher-text. For this reason RC4 Cipher is vulnerable to a number of attacks. Thereupon, this paper proposes a new modification of the RC4 to strong it. This achieved by modifying key-stream generator based on linear equation with four state tables for generating random numbers. Key control is used for selecting one state table to apply # operation, then performing forward and backward effects to generate the key-stream that used in encryption and decryption. Being evaluated, the results obtained from the statistical probabilities prove that our proposed algorithm is more complex than the standard algorithm by using different key lengths. Also, our proposed RC4 pass the randomness in most metrics in NIST

Fixed point chaos based stream cipher (FPC-SC) is presented in this paper to encrypt the speech signal. Fixed point chaos based pseudo random bit generator (FPC-PRBG) is used as key sequence in stream cipher system. Two chaotic Lorenz and Chen systemsare combined to generate Gold FPC-PRBG. The results show that FPC-PRBG has good statistical randomness and encryption performance measure and can be used to produce high speech security level. FPC-PRBG is implemented using Xilinx system generator (XSG) with Xilinx Virtex 4 FPGA device, the system is accessed routed in this device with throughputs 818.64,7978.88 and 780.24 Mbits/sec for Lorenz, Chen and Gold FPC-PRBG respectively, where 40 bits fixed point operation are used.

Security is an important issue, especially in today’s technologically advanced society. Global System for Mobile Communications (GSM) is a world-wide standard for digital wireless communication. GSM uses A5/1 stream cipher in order to provide privacy on air communication. This paper introduce new improvements to the A5/1 stream cipher in order overcome the weakness that appear in clocking mechanism that used in A5/1 stream cipher. New S-box generation is proposed to increase the efficient for A5/1 majority function and improve randomness features. The randomness results confirm that the output bit-stream generated by the proposed stream cipher has improved the randomness performance.

In this paper, a secure data hiding method is introduced. It increases the security of embedded data through combining between the steganography and cryptography. First, the secrete message is divided into blocks with same size according to length of key stream that is generated using nonlinear key generator. This key is used to encrypt the first block in secret message using the stream cipher, whereas the other blocks are encrypted depending on the behavior of cipher block chaining (CBC) mode that turn on the stream cipher in order to
guarantee no duplicated encrypted blocks. In our CBC mode the current ciphertext block will became a key stream to encrypt the next plaintext block, and so on. After encryption stage complete, the encrypted massage are embedded randomly in bmp image using LSB insertion method to increase the security.

The producing composite materials of dual reinforcement in which the matrix material is aluminum reinforced with two types of ceramic particles : which are Alumina (50μm

Keywords

composite materials; wear test ; Al2O3; SiC: Al