Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : AES

A modified Matrices Approach in Advanced Encryption Standard Algorithm

Abdul Monem S. Rahma; Atheer M. Abbas

Engineering and Technology Journal, 2019, Volume 37, Issue 3B, Pages 86-91
DOI: 10.30684/etj.37.3B.4

The cryptographic algorithms became the main proceeding for protection of very important data from unauthorized access. There are several cryptographic algorithms to ensure the data, but algorithms must be selected according to speed, strength and the implementation. Thus, choosing the advance encryption standard (AES) for encryption and decryption data because its speed and strength of encryption, flexible, complex processing and its resistance to Brute-force attack. This paper presents enhancement of the AES algorithm to increase the security of the encrypted documents by using different sizes data matrices based on multiple irreducible polynomials with order 2, 4, and 8. The proposed modifications results tested and provide a high randomness.

Proposal for Complex AES Security using key Generator and Text Permutation

Shatha Habeeb

Engineering and Technology Journal, 2012, Volume 30, Issue 12, Pages 2067-2075

Advanced Encryption Standard (AES) is a symmetric-key encryption each of
these ciphers has a 128-bit block size, with key sizes of 128, 192 and 256 bits. The AES cipher is specified as a number of repetitions of transformation rounds that convert the input plaintext into the final output of ciphertext. Each round consists of several processing steps, including one that depends on the encryption key[1,2]. This research proposes a technique intended to make the Advanced Encryption
Standard (AES) more safe and secure. Through the generation of random key, and permutation key sites in each round, instead of the process of expanding key locations in addition to the proposed permutation the plaintext before entering the encryption and inverse permutation for resulting ciphertext.

A Modification of TEA Block Cipher Algorithm for Data Security (MTEA)

Gaidaa Saeed Mahdi

Engineering and Technology Journal, 2011, Volume 29, Issue 5, Pages 822-832

This paper attempts to develop a simple, stronger and safer cryptographic
algorithm which would not only be a secure one, but also reduces total time taken
for encryption and decryption. The modified algorithm MTEA is a new secret-key
block cipher of 64 bit that uses good features of Tiny Encryption Algorithm
(TEA) and RC6 algorithms. The proposal algorithm uses the RC6 encryption
algorithm as key scheduling to generate subkey. These generated key will be used
in META algorithm's round. An effort is made to enhance performance of the
resulting algorithm. Proposed MTEA algorithm improved TEA algorithm which is
a simple classical Feistel network with 64 rounds and operating on 64 bit blocks of
plaintext to produce 64 bit blocks of ciphertext with 128 bit key.

Effect of Using Header Compression Method in TCP/IP Protocol Over HDLC in SCADA System

Sarcot N. Abdullah; Bassim Abdulbaki Jumaa; Omar A. Mohamad

Engineering and Technology Journal, 2009, Volume 27, Issue 15, Pages 2806-2813

Most of the header information remains constant over the life-time of the connection. For TCP connection many fields are constant and others change with small values. To initiate compression of the headers of a packet stream, a full header is transmitted over the link. The compressor and decompressor store most fields of this full header as reference. The reference consists of the fields of the headers whose values are constant and thus need not be sent over the link at all, or change little between consecutive headers so that it uses fewer bits to send the difference from the previous value compared to sending the absolute value. To improve interactive response time and to decrease the header overhead on the system we used the method of Compressing Protocol Headers (TCP/IP). Also it is used to compress the HDLC header. The simulated communication protocols have been tested between two PCs and the time delay, throughput and utilization have been measured.

Type-3 Feistel Network of The 128-bits Block Size Improved Blowfish Cryptographic Encryption

Ashwaq T. Hashim

Engineering and Technology Journal, 2009, Volume 27, Issue 2, Pages 235-246

In this paper, a new secret-key block cipher called 128-bits Blowfish is
proposed which is an evolutionary improvement of 64-bits Blowfish designed to
meet the requirements of the Advanced Encryption Standard (AES) to increase
security and to improve performance. The proposed algorithm will be used a
variable key size up to 192 bytes. It is a Type-3 Feistel network iterated simple
function 16 times. Specifically, in this proposed algorithm, a combination of four
S-boxes lookups, multiplications as well as fixed and data-dependent rotations will
be used. Mixing round provide different levels of security, efficiency, flexibility
and good avalanche effect. The proposal is word-oriented, in that all the internal
operations are performed on 32-bit words. So it is possible to implement the
algorithm on smart cards efficiently.