A Vigenere-6S-Substitution-2S-Transposition Encryption Algorithm for Invisible Watermarking

The growth of cryptography is rapid, and the need for communication security on the internet and digital files is of utmost importance. The topic of encryption is highly discussed when it comes to ensuring the data security and integrity. Security is the trend of cryptography which provides a solution to the information security problems that arise in the digital world. This paper presents a novel Vigenère cipher algorithm with 6S-Substitution and 2S-Transposition (6SS-2ST) techniques in identifying the authenticity of a digital image. The study is implemented and simulated using PHP and is analyzed using the four metrics namely the data capacity, luminosity histogram, comparison by pixel, and hamming distance. The results for the data capacity analysis reveals that the five (5) image data sets comprising the original image, protected image, and same as original image yield comparable number of byte results. In the analysis for luminosity histogram, the five (5) image data resulted a match both for embedding and extracting processes. Also, there are five (5) image files used in calculating the hamming distance. Each image has an encrypted value generated for the original file protected file, and the file for same as original, that produce a zero result. Thus, the zero result for the hamming distance means providing an invisible watermark for the data security. Therefore, the results of the study are proof that the new Vigenere-6SS-2ST encryption algorithm was able to watermark the files effectively.