An Enhancement of Text Encryption Algorithm with Hybrid Two-Square Cipher and Columnar Transposition Cipher

Purpose–Enhance the Two-Square Cipher's effectiveness by developinganalgorithmto address vulnerabilities in plaintext variations, character set limitations and encryption performance. Method –Proposedadjustmentsincludeexpandingthegridto14x14,usingtableshuffling instead of random character insertion, and strategically inserting random special characters in odd-length plaintexts. Results –The algorithm demonstrated improved encryption, producing more random ciphertext sequences and successfully recovering original characters during decryption. Conclusion –The developed algorithm outperforms the current Two-Square Cipher, enhancing encryption security and adaptability to different plaintexts. Recommendations –Further enhance the algorithm to address specific issues such as character transformation, while maintaining the grid size at 14x14. Research Implications –Contributes to advancing cryptographic techniques, highlighting the importance of addressing vulnerabilities in existing ciphers to strengthen data security. Keywords –two-square cipher, columnar transposition, text encryption, cryptography, block and stream cipher