An implementation of Rabin-p cryptosystem and affine cipher in a hybrid scheme to secure text

Abstract

Abstract One way to keep digital information secure is by using cryptographic techniques. With respect to its keys, cryptography generally is divided into two types: symmetric and asymmetric. Symmetric cryptography algorithm uses the same key in both encryption and decryption while asymmetric uses different keys for each of these processes. Asymmetric cryptography algorithm is known to be ineffective to encrypt big messages since it takes more CPU time to do the computation and the resulting ciphertext is usually much bigger than the original message. To eliminate these problems, in this research, we combine Rabin-p cryptosystem, an asymmetric cryptography algorithm, and affine cipher, a symmetric cryptography algorithm, in a hybrid scheme in order to secure messages from unwanted parties. The affine cipher is used for message encryption while Rabin-p is used for affine cipher’s key encryption. The result of this research is a hybrid cryptography scheme that can encrypt and decrypt message in the form of *.pdf files and be able to restore the message without losing integrity.