Quantum encryption design overcomes Shannon's theorem to achieve perfect secrecy with reusable keys

TL;DR

This paper introduces a quantum encryption method that achieves perfect secrecy with reusable keys, surpassing Shannon's classical limits, and offers practical benefits like no need for authentication and silent tampering detection.

Contribution

The work presents the first quantum encryption scheme that overcomes Shannon's theorem to enable perfect secrecy with reusable keys, demonstrating a quantum advantage.

Findings

Achieves perfect secrecy with reusable keys using quantum mechanisms

Does not require authentication in the encryption process

Includes silent tampering detection capabilities

Abstract

Shannon's perfect-secrecy theorem states that a perfect encryption system that yields zero information to the adversary must be a one-time pad (OTP) with the keys randomly generated and never reused. In this work we design the first encryption method (classical or quantum) that overcomes Shannon's theorem to achieve perfect secrecy with reusable keys. Because the mechanisms used are fundamentally quantum, Shannon's theorem remains true in the classical regime. Consequently, the quantum encryption design demonstrates decisive quantum advantage by achieving a goal impossible for classical systems. Finally, the design has major practical advantages by not requiring authentication and having silent tampering detection.