Application of Linear Congruent Generator in Affine Cipher Algorithm to Produce Dynamic Encryption

Abstract

Modification of the original message (plaintext) with the LCG random number generator algorithm and encryption with the affine cipher algorithm to produces a dynamic and safe random message (ciphertext) compared to just the affine cipher algorithm. The plaintext is converted to ASCII code and stored in a data list. The data list that contain the plaintext changes the position of the data where each plaintext column is moved to an odd column and even columns are filled by random numbers generated by LCG. The data list is then changed again by adding value to each column with random numbers generated by the programming language and then it encrypted with the affine cipher algorithm. The total number of ciphertexts can be twice as many as the plaintext. The results obtained are not the same ciphertext character even though the plaintext has the same character. Ciphertext generated in the first run program will be different for the next run program or dynamic encryption. To restore a ciphertext to the plaintext is done based on the affine cipher decryption function and the steps to modify the message that was done before.

A combination of hill cipher and RC4 methods for text security

“…The fundamental functions in cryptography are encryption and decryption [16], [17]. a. Encryption Encryption is the process of changing an original message (plaintext) into a message in coded language (ciphertext) [18], [19]. Encryption is part of cryptography and is very important so that the security of the data sent can be kept confidential [20].…”

A Modified Polybius Cipher with a New Element-in-Grid Sequencer

“…Various classical ciphers such as Railfence cipher [13], [14], Polybius square cipher [15]- [19], Playfair cipher [20]- [22], Permutation cipher [23], Homophonic substitution cipher [24], [25], Hill cipher [26], Grille cipher [27], Four-square cipher [23], Enigma machine cipher [23], Caesar cipher [28]- [30], Base64 cipher [31]- [33], Affine cipher [23], [34]- [36], and ADFGVX cipher [23], [37]- [39] to name some, are being incorporated with block ciphers, among others, to solve the constraints in IoT. Among the classical ciphers, the Polybius Cipher, known as the Polybius square, is identified as one of the commonly used methods for such purpose [40]- [42].…”

Polybius Square in Cryptography: A Brief Review of Literature

“…Some ciphers require the key to produce various transformations and substitutions, depending on the cipher being used [16]. Some of the classical ciphers found in the literature that are still being used today are ADFGX cipher [17]- [19], Affine cipher [19]- [22], Atbash cipher [23], Auto-key cipher [24], Baconian cipher [19], [25], Base64 cipher [26]- [28], Beaufort cipher [19], Caesar cipher [29]- [31], Grille cipher [32], Hill cipher [33], Homophonic Substitution cipher [34], [35], Playfair cipher [36]- [38], Polybius cipher [39], Railfence cipher [40], [41] and more. Among these, the Polybius cipher is considered to be one of the most widely used ciphers.…”