Mustansiriyah Journal of Pure and Applied Sciences

Enhance Key Stage Generation for Developing Kasumi Encryption Algorithm

Ahmed Ali salih

Computer Science Department, College of Education, Mustansiriyah University

Ali Shakir Mahmood

DOI: https://doi.org/10.47831/mjpas.v2i4.116

Keywords: Cryptography, Block cipher, Kasumi, Key Schedule, NIST statistical test

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Abstract

Today, data security is a critical component of the efficient performance of every organization's diverse requirement, one of the important requirements is to provide a secure connection for data transmission in organization's networks. Cryptography algorithms are used to protect transmitted data from unauthorized access. Every day, a great deal of research is being done. The process of encrypting data is currently under development. Therefore, a substantial technological or research effort is still required. Cellular networks and secure communication. This proposal calls for the development of a new encryption system based on Using random keys in all the rounds. That’s mean we generated random keys as 128 bits for each round and save it in an array with size (8×8) because we have 8 rounds and each key divided into 8 sub keys as 16 bits for each to use in encryption and decryption. The developed random keys and traditional algorithm keys were tested with statistical tests of NIST, which made up a comparison and conclusion that the developed keys have a higher randomness specially in linear complexity, Frequency within block and random excursion tests, which leads to a better quality of encryption. Then we could test the cipher text with frequency within block test that was evaluated by (0.49590998713105255) and the approximate entropy test that was evaluated by (0.4922198616875501) for each cipher text which resulted from standard and modified Kasumi algorithm that’s means we can conclude that our modified Kasumi algorithm achieved more secure data in its resulted cipher text.