# Enhanced R\'{e}nyi Entropy-Based Post-Quantum Key Agreement with Provable Security and Information-Theoretic Guarantees

## TL;DR

This paper introduces an enhanced post-quantum key agreement protocol based on Rényi entropy, offering provable information-theoretic security against quantum attacks with efficient implementation and broad applicability.

## Contribution

The paper develops a novel Rényi entropy-based protocol with entropy-preserving operations, quantum-resistant commitments, and security proofs in the quantum universal composability framework, advancing post-quantum cryptography.

## Key findings

- Achieves 128-bit quantum security guarantees.
- Provides a polynomial-time protocol with $ ext{O}(n^{2})$ communication complexity.
- Demonstrates resilience against Grover's algorithm and quantum memory attacks.

## Abstract

This paper presents an enhanced post-quantum key agreement protocol based on R\'{e}nyi entropy, addressing vulnerabilities in the original construction while preserving information-theoretic security properties. We develop a theoretical framework leveraging entropy-preserving operations and secret-shared verification to achieve provable security against quantum adversaries. Through entropy amplification techniques and quantum-resistant commitments, the protocol establishes $2^{128}$ quantum security guarantees under the quantum random oracle model. Key innovations include a confidentiality-preserving verification mechanism using distributed polynomial commitments, tightened min-entropy bounds with guaranteed non-negativity, and composable security proofs in the quantum universal composability framework. Unlike computational approaches, our method provides information-theoretic security without hardness assumptions while maintaining polynomial complexity. Theoretical analysis demonstrates resilience against known quantum attack vectors, including Grover-accelerated brute force and quantum memory attacks. The protocol achieves parameterization for 128-bit quantum security with efficient $\mathcal{O}(n^{2})$ communication complexity. Extensions to secure multiparty computation and quantum network applications are established, providing a foundation for long-term cryptographic security.