A Secure Variant of the Hill Cipher

TL;DR

This paper introduces a secure variant of the Hill cipher that maintains efficiency and enhances security, addressing its known vulnerabilities to cryptanalysis while preserving its pedagogical value.

Contribution

A novel cryptographic scheme that makes the Hill cipher secure against known-plaintext attacks without sacrificing efficiency.

Findings

The proposed scheme resists known-plaintext attacks.

It retains the computational efficiency of the original Hill cipher.

The scheme includes a new cryptographic protocol for secure ciphering.

Abstract

The Hill cipher is a classical symmetric encryption algorithm that succumbs to the know-plaintext attack. Although its vulnerability to cryptanalysis has rendered it unusable in practice, it still serves an important pedagogical role in cryptology and linear algebra. In this paper, a variant of the Hill cipher is introduced that makes the Hill cipher secure while it retains the efficiency. The proposed scheme includes a ciphering core for which a cryptographic protocol is introduced.