Hybrid encryption using playfair and RSA cryptosystems

Document Type : Research Paper


Department of Applied Sciences, Mathematics and Computer Applications, University of Technology, Baghdad, Iraq


The security is demanded to transport important data over the network. In this work a hybrid
encryption depending on playfair cipher and RSA algorithm is proposed to give more confidentially
and get rid of the defects of the two methods. The first cipher text is obtained by playfair cipher by
using (812) expanded key matrix that is filled by decimal ASCII characters of Alphabets, numbers
and common characters of ASCII table while the final cipher text is obtained by RSA cryptosystem
by applying it for blocks of two characters. The proposed hybrid encryption avoids to take large
numbers in RSA algorithm and performs complex operations that need a long time to do. The
proposed hybrid cipher is tight security that is difficult to analyze and detect from hackers and