Jurnal Pepadun
Vol. 6 No. 3 (2025): December

Hybrid Hill Cipher ASCII 256 and RSA Cipher in Securing Messages

Sandi Saputra (Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Lampung)
Fitriani Fitriani (Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Lampung)
Ahmad Faisol (Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Lampung)
Wamiliana Wamiliana (Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Lampung)
Siti Laelatul Chasanah (Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Lampung)



Article Info

Publish Date
15 Dec 2025

Abstract

Secure communication requires encryption methods that strike a balance between efficiency and key protection. This study proposes a hybrid cryptosystem integrating the Hill Cipher and the RSA Cipher. The Hill Cipher, based on modular matrix multiplication, achieves fast encryption but lacks secure key distribution, whereas RSA provides robust asymmetric key management at a higher computational cost. By encrypting the Hill Cipher key with RSA, the proposed method strengthens resistance to brute-force and key compromise attacks. A Python-based implementation was developed and tested on messages of varying lengths. Experimental results show that the hybrid system maintains the efficiency of the Hill Cipher while significantly improving key security, with time complexity increasing modestly due to RSA key operations. Two scenarios were analyzed depending on whether the message length is divisible by the key matrix size, confirming the scheme’s flexibility. This approach demonstrates a practical and secure solution for protecting digital communication against cryptanalysis.

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Journal Info

Abbrev

jurnal

Publisher

Subject

Computer Science & IT

Description

Pepadun Journal is a journal to publish research in the fields of computer science, information systems, and informatics to researchers, scientists, and professionals. For every edition published by the Pepadun Journal, we put our effort: Using standard procedures and times for submitted ...