Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : encryption

A Modification on Key Stream Generator for RC4 Algorithm

Suhad M. Kareem; Abdul Monem S. Rahma

Engineering and Technology Journal, 2020, Volume 38, Issue 2B, Pages 54-60
DOI: 10.30684/etj.v38i2B.404

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

Image Encryption Using Block Cipher Based Serpent Algorithm

Yossra Hussain Ali; Haider Aabdali Ressan

Engineering and Technology Journal, 2016, Volume 34, Issue 2, Pages 278-286
DOI: 10.30684/etj.34.2B.10

In an encryption scheme, the message or information, referred to as plaintext, is encrypted using an encryption algorithm, generating cipher textthat can only be read if decrypted.A proposal algorithm forimages protectionis depending on the block cipher serpent algorithm infeistel network structure, because numbers of round and linear transformation function and used block size of 512 bits rather than 128 bitshas more complexity for attacker or unauthorized person to discover original images.In modified serpent, the correlation coefficient decreases to below the traditional serpent algorithm. When 64*64 pixel bitmap image is used the correlation coefficient for gray level between plain image and cipher image is (0.0023) in modified serpent and (0.0814) in traditional serpent.

Proposal New S-box for AES Algorithm Depend on A.I Bee Colony

Alaa Kadhim; Sura Khalaf

Engineering and Technology Journal, 2015, Volume 33, Issue 1, Pages 12-24

The AES algorithm, also called the Rijndael algorithm, is a symmetric block cipher, where the data are encrypted/ decrypted in blocks of 128 bits. Each data block is modified by several rounds of processing, where each round involves four steps. Three different key sizes are allowed: 128 bits, 192 bits, or 256 bits, and the corresponding number of rounds for each is 10 rounds, 12 rounds, or 14 rounds, respectively. From the original key, a different “round key” is computed for each of these rounds. The single nonlinear step is the Sub Bytes step, where each byte of the input is replaced by the result of applying the “S-box” function to that byte. This nonlinear function involves finding the inverse of the 8-bit number, considered as an element of the Galois field GF (216). The Galois inverse is not a simple calculation, and so many current implementations use a table of the S-box function output. This table look-up method is fast and easy to implement. S-box is influenced by linear and differential cryptanalysis and also interpolation attacks. In this paper intended a new approach for the design of s-box based on the bee colony algorithm to increase the power of s-box and enhanced resistance against attacks through the use of artificial intelligence algorithms.

Proposal to Complex DES Security Using Diffie Hellman Injection

Shatha habeeb Jafar

Engineering and Technology Journal, 2011, Volume 29, Issue 6, Pages 1216-1226

Data Encryption Standard (DES) is based on a round of starters, from the
results of the use of multi-stage permutation and replacement to the more complex
algorithm which adopts the symmetric key. Diffie- Hellman is based key
generation algorithm puts a shared secret key between two parties A and B, which
depends on the prime number.
This research suggest a technique it is objective is the blending between the
two encryption methods DES and Diffie Hellman to make DES more safe and
secure. That by propose two options first one include injection the encryption DES
after the seventh round with Diffie-Hellman just as key distribution algorithm then
the results of the last back to the eighth round to complete the encryption process
of DES. The second include injection the encryption DES after the eighth round
with Diffie-Hellman just as key distribution algorithm to generate key the results
of the eighth round will be encrypted using stream cipher then back to the ninth
round to complete the encryption process of DES.

Proposed Hybrid-Encryption System for Multicast Network

Mohammad Natiq Fadhil Ibraheem

Engineering and Technology Journal, 2010, Volume 28, Issue 24, Pages 7027-7036

In this paper the proposed method based on two encrypted algorithms (Public key, and Block cipher) at the same time, it allowed a sender to encrypt the multicast packet and forward it into the packet network on the optimal distribution tree. The packet may be replicated at the optimal locations in the network and delivered to all the receivers. The receivers are capable of decrypting the packet and forwarding the
packet in the secure network environment. The sender must encrypt packets using a shared key that all the legitimate receivers use to decrypt thepackets. The security of the system is based on the ability to control the distribution of the keys only to those legitimate receivers.

Measurement of Encryption Quality of Bitmap Images with RC6, and two modified version Block Cipher

Baedaa H. Helal; Ashwaq T. Hashim

Engineering and Technology Journal, 2010, Volume 28, Issue 17, Pages 5603-5613

With the fast evolution of digital data exchange, security information
becomes much important in data storage and transmission. Due to the increasing
use of images in industrial process, it is essential to protect the confidential image
data from unauthorized access. In this paper, RC6 with two modified version 512
bit RC6 and 640 bit RC6-Cascade encryption algorithms will be analyzed to
investigate the encryption efficiency for them to digital images and providing a
new mathematical measure for encryption efficiency. Detailed results in terms of
security analysis and implementation are given. Comparative study with three
versions of RC6 encryption algorithms is shown the superiority of the modified
algorithms. Three measuring quality factors will be considered to evaluate and
compare between the three encryption algorithms RC6, 512 RC6, and 640 RC6-
Cascaded. These measuring factors are the maximum deviation, the correlation
coefficient and irregular deviation.