Hybrid encryption using playfair and RSA cryptosystems

Salih, Raghad K.; Yousif, Madeha Sh.

doi:10.22075/ijnaa.2021.5379

Hybrid encryption using playfair and RSA cryptosystems

Document Type : Research Paper

Authors

Raghad K. Salih

Madeha Sh. Yousif

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

10.22075/ijnaa.2021.5379

Abstract

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 intruders.

Keywords

Playfair

RSA algorithm

ASCII and Hybrid encryption

[1] M.A. Islam, N. Islam and B. Shabnam, A modified and secured RSA public key cryptosystem based on ”n” prime
numbers, J. Comput. Commun. 6 (2018) 78.
[2] S.Y. Kayode and G.K. Alagbe, An Improved RSA Cryptosystem Based on Thread and CRT, e-Academia J. 6
(2017).
[3] A.C. Licayan, B.D. Gerardo and A.A. Hernandez, Enhancing playfair cipher using Seed based color substitution,
16th IEEE Int. Colloq. Signal Proc. Appl. 2020, pp. 242-246.
[4] P. Pal, G.S. Thejas, S.K. Ramani, S.S. Iyengar and N.R. Sunitha, A variation in the working of playfair cipher,
In IEEE 4th Int. Conf. Comput. Syst. Inf. Tech. Sust. Solution, India, 2019.
[5] S.S. Shireen, B.M. Krishna, K.N.L. Prasanna and A.P.C. Reddy, FPGA based RSA authenticated data hiding in
image through steganography, Int. J. Innov. Tech. Explor. Engin. 8(4) (2019) 550–554.
[6] R.S. Villafuerte, A. M. Sison, A. A. Hernandez and R. P. Medina, Randomness Evaluation of the Improved
3D-Playfair (i3D) Cipher Algorithm, 12th Int. Conf. Commun. Software Networks 2020, pp. 240–245.
[7] M.S. Yousif, R.K.Salih and N.M.G. Alsaidi, A new modified playfair cipher, AIP Conf. Proc. 2019