Implementation of vigenere cipher 128 and square rotation in securing text messages

Abstract

Information that can be in the form of text, image, audio, and video, is a valuable asset that needs to be secured from unauthorized parties. This research aims to study the implementation of Vigenere cipher 128 (VC-128) and square rotation to secure text information. The square rotation is applied to increase the security of the encryption results obtained from VC-128. The randomness of the rotation results was measured using Shannon entropy based on the distance between characters, and the Avalanche Effect measured changes in the encryption results compared to the original text. The square rotation can increase the randomness of the VC-128 encryption results, as indicated by an increase in entropy values. The highest increase in entropy of 34.8 % occurs in repetitive texts with the square size that produces optimal entropy was a 9x9 medium-size square. The Avalanche effect for each test data shows inconsistent results ranging from 44.5 % to 49 %.

Bit-based cube rotation for text encryption

“…The operation of the cube rotation imitates the operation of square rotation, whereas the square rotation was originally intended to optimize the Vigenere cipher [26]. Square rotation is a process to get a change in the position of an element in a square matrix by rotating it through a certain center and/or angle.…”

“…The mathematical notation for CW rotation can be written as ( 1) and ( 2) for CCW rotation [26]. S is the array before rotation while S' is the array after rotation, i is the row index, and j is the column index.…”

Implementasi Vigenere Cipher Pada Aplikasi Myprichat End-to-End Encrypted SMS Berbasis Android

“…Semakin berkembangnya teknologi dan mudahnya mendapatkan informasi pada era sekarang ini, semakin masyarakat memahami pentingnya pengamanan dalam data informasi pribadi termasuk pada komunikasi pesan teks. Salah satu bentuk pengamanan informasi adalah dengan melakukan enkripsi menggunakan metode atau teknik kriptografi [2]. Ketika suatu pesan dikirim dari suatu tempat ke tempat lain, isi pesan tersebut mungkin dapat disadap oleh pihak lain yang tidak berhak untuk mengetahui isi pesan tersebut.…”

Vigenère Cipher Algorithm Optimization for Digital Image Security using SHA512

“…Another research that aims to compare the avalanche effect has been carried out by expanding the range of characters that can be accommodated to 128 pieces according to the number of standard ASCII characters and rotating the square matrix. The process implementation produces an avalanche effect value of around 45% to 49% [15]. In their research on the Vigenère Cipher implementation, Fadlil et al developed a unique technique, merging Artificial Neural Networks (ANN) with Vigenère Ciphers.…”