Modified Vegenere Cipher to Enhance Data Security Using Monoalphabetic Cipher

Abstract

The rapid progression of exchange data by public networks is important, especially in information security. We need to keep our information safe from attackers or intruders. Furthermore, information security becomes needed for us. Many kind cipher methods of cryptography are improved to secure information such as monoalphabetic cipher and polyalphabetic cipher. Cryptography makes readable messages becoming non-readable messages. One of the popular algorithms of a polyalphabetic cipher is Vigenere cipher. Vigenere cipher has been used for a long time, but this algorithm has weaknesses. The calculation of the encryption process is only involving additive cipher, it makes this algorithm vulnerability to attacker based on frequency analysis of the letter. The proposed method of this research is making Vigenere cipher more complex by combining monoalphabetic cipher and Vigenere cipher. One of the monoalphabetic ciphers is Affine cipher. Affine cipher has two steps in the encryption process that are an additive cipher and a multiplicative cipher. Our proposed method has been simulated with Matlab. We also tested the vulnerability of the result of encryption by Vigenere Analyzer and Analysis Monoalphabetic Substitution. It shows that our method overcomes the weakness of Vigenere Cipher. Vigenere cipher and Affine cipher are classical cryptography that has a simple algorithm of cryptography. By combining Vigenere cipher and Affine cipher will make a new method that more complex algorithm.

Secured personal notes using face recognition-based decryption

“…Because the encryption calculation only uses additive cipher, this algorithm is susceptible to attacks based on letter frequency analysis. The research's suggested approach entails combining the Vigenere encryption with a monoalphabetic cipher to increase its complexity [Kurniawan Muchamad(2019)]. A lot of introductory cryptology and computer security courses begin with or include a discussion of classical ciphers, which typically considers some cryptanalysis methods used to break them.…”

E-ART: A New Encryption Algorithm Based on the Reflection of Binary Search Tree

“…These ciphers are highly susceptible to a cryptanalysis attack [11]. However, there have been some recent enhancements [12,13] to these ciphers to overcome these attacks and to increase security and maintain performance. For example, Marzan and Sison [14] enhanced the key security of the Playfair Cipher Algorithm using a combination of a 16 × 16 matrix, XOR, two's complement, and bit swapping.…”

Analisa Algoritma Kriptografi Klasik Caesar Cipher Viginere Cipher dan Hill Cipher – Study Literature

“…Frobenius dan Hidayat yang memodifikasi algoritma Caesar, Vigenere, Hill dan Playfair yang dapat menyisipkan teks pada gambar tanpa mengubah ektensi[19]. Penelitian oleh Agustini dkk yang melakukan pengabungan onoalphabetic cipher dan Vigenere cipher dengan menerapkan key enkripsi sebanyak dua key[11]. Penelitian oleh Megantara dkk yang melakukan kombinasi algoritma Hill Cipher dengan LSB Cipher dalam mengamankan RGB image dengan proses membuat sistem penentuan pilihan panjang karakter pesan yang terdiri dari 32, 64 dan 128 karakter, yang kemudian dienkripsikan kembali oleh Hill Cipher[17].…”