A new approach of classical Hill Cipher in public key cryptography

Secure message transformation promote the creation of various cryptography systems to enable re￾ceivers to interpret the transformed information. In the present age of information technology, the secure transfer of information is the main study of most agencies. In this study, a particular symmetric cryptography system, Hill Cipher method, is enhanced with the help of encryption and decryption algorithms of the asymmetric RSA cryptography system to avoid certain problems. Previous results show that the original Hill algorithms are still insufficient because of their weakness to known plaintext attack, and a modification of the Hill Cipher cryptography system is therefore presented to increase its invulnerability. The enhancement focuses on implementing the RSA algorithms over the Hill Cipher to increase its security efficiency. The suggested method relies on the security of the RSA and Hill Cipher cryptosystems to find the private decryption keys, and thus is much more secure and powerful than both methods applied separately. Also secure and dynamic generation of the Hill Cipher matrix instead of using static matrix are proposed. This new approach is composed of a public key cryptosystem that has a shared secret key (between participants only), public key (announced to all), and two private keys (for each person). Therefore, this new modification can increase the invulnerability of the Hill Cipher against future attacks during transmission of information between agencies in this age of information technology

A new approach of classical Hill Cipher in public key cryptography Keywords:

Asymmetric cryptosystem , Hill Cipher , Invertible Key Matrix , Involutory matrix , RSA cryptosystem , Symmetric cryptosystem