DEVELOPMENT OF A HYBRID DATA ENCRYPTION AND DECRYPTION TECHNIQUE USING SYMMETRIC AND ASYMMETRIC CRYPTOGRAPHY ALGORITHMS

Abstract

With the increasing growth of internet and networking systems, security of data is of paramount importance in many applications as diverse as military intelligence, medical information, government’s information and service providers. Cryptography is the technique used for hiding confidential information from the attack of an intruder, and different techniques have been developed to combat intrusion. Symmetric technique of encryption provides a faster means of encrypting data but suffers from brute force attack and key management problem. Asymmetric techniques on the other hand solve the problem of key management but are slower than the symmetric counterpart. In view of the above, this research work combines and employed the advantages of both techniques, that is, the speed of the symmetric systems and the security of asymmetric systems to form a hybrid system. The developed hybrid technique uses a combination of Data Encryption Standard (DES) and Rivest Sharmin Addleman (RSA) algorithms. The DES was used for encryption of the data because of its speed, while RSA was used for encrypting the session key of the DES for proper key distribution and management. The technique was implemented in Microsoft visual C# and a Graphical User Interface was developed to facilitate performance evaluation. The performance of the developed hybrid technique was done based on encryption and decryption time, throughput, average data rate and total encryption ratio for different input text and image data sample of varying sizes. The performance of the hybrid technique was compared to some other hybrid techniques in literature, using the same size of input text and image data samples; and the same system requirements. The results obtained show that the developed hybrid technique has better performance in terms of speed of encryption (encryption time), throughput and the CPU power consumption, over all other tested hybrid techniques.