Enhancement of the 95×95 Vigenère Cipher Using a 3D Tabula Recta and a New Key Generation Technique in Application to Database Encryption

This study enhances the 95×95 Vigenère cipher by addressing its limitations. The current cipher struggles with encrypting non-English alphabets and is vulnerable to kasiski, brute force, and frequency analysis attacks. The researchers proposed an enhanced version by employing two keys generated from a cryptographically secure random number generator (CSPRNG), expanding the character set, and using a 3D tabula recta. The enhanced cipher successfully encrypts and decrypts various alphabets like Hangul, Arabic, Japanese, and Chinese, using a subset of printable characters from the Unicode Basic Multilingual Plane (BMP). It exhibited improved resistance to kasiski attacks, as the produced ciphertext lacked patterns such as bigram, trigram, up to n numbers of n-gram. The expanded character set and 3D tabula recta significantly increased the key permutations, making brute force attacks less likely to succeed. The algorithm also provided better defense against frequency analysis due to the utilization of two secure keys.