Revisiting the Unicity Distance through a Channel Transmission Perspective

TL;DR

This paper reinterprets the classical unicity distance in cryptography through the lens of information theory by modeling encryption as a noisy channel, providing a new proof and perspective grounded in communication theory.

Contribution

It offers a novel channel transmission perspective on unicity distance and provides an information-theoretic proof aligning with Shannon's classical results.

Findings

Derived a simple information-theoretic proof of unicity distance

Provided a channel transmission interpretation of unicity distance

Reconnected cryptographic concepts with communication theory principles

Abstract

This paper revisits the classical notion of unicity distance from an enlightening perspective grounded in information theory, specifically by framing the encryption process as a noisy transmission channel. Using results from reliable communication theory, we derive a simple information-theoretic proof of the same unicity distance formula as in Shannon's classical result and a channel transmission interpretation of the unicity distance.