Improving the Control Strategy in two-way deterministic cryptographic protocols

TL;DR

This paper proposes a novel control strategy for two-way deterministic cryptographic protocols using unitary transformations instead of measurements, enhancing security especially for odd prime power alphabet sizes.

Contribution

Introduces a new control method based on unitary transformations for two-way cryptographic protocols, improving security for specific alphabet sizes.

Findings

Security increases with alphabet size d

Method effective for d being an odd prime power

Protocol security is demonstrably improved

Abstract

We introduce a new control strategy on a two-way deterministic cryptographic scheme, which relies on a suitable unitary transformation rather than quantum measurement. The study is developed for d-ary alphabets and the particular choice of the transformation works when d is an odd prime power. It leads to an improvement of the protocol security, which we prove to increase with the alphabet order d.