A Hybrid Encryption Technique For Increasing Data Security

Abstract

Computer security 1s considered as one of the most important issues nowadays in computer business especially after the revolution of computer networks and communication systems in different areas, academic studies, commercial transactions, banking, etc... Consequently scientific research was developed very much lately in this area. This thesis is concerned about a very important and significant part of the computer security studies, which is "Encryption". Due to the ongoing mcrease m the processing power of the machines, research is concerned about the threat for the current encryption algorithms, especially the exhaustive key-search attacks which represent the most known and major attacks in this area. This work first gives a comprehensive review of all issues, next it suggests and implements a hybrid technique (DR-CAS) for encryption by cascading two block ciphers (DES and RC5). One of the significant advantages gained from this technique is to increase the key diversity, which will protect against the foreseen key-search attacks. The work concludes by an evaluation for both DES and RC5 algorithms separately. Five different evaluation criteria are specifically chosen. The same criteria are applied to the DR-CAS technique to ensure its security and several future work recommendations are given.