arXiv subjects

Ruopengyu Xu

Publications and source records attributed to Ruopengyu Xu.

4 recordsLinked to original sources

arXiv2025

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

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.

cs.CR↗

arXiv2025

Tight Quantum-Security Bounds and Parameter Optimization for SPHINCS+ and NTRU

The imminent threat of quantum computing necessitates quantum-resistant cryptosystems. This paper establishes tight security bounds for two NIST PQC finalists: SPHINCS+ (hash-based) and NTRU (lattice-based). Our key contributions include: (1) A quantum attack model incorporating decoherence effects ($\tau_d$) and parallelization limits; (2) Improved entropy concentration inequalities reducing SPHINCS+ parameters by 15-20\%; (3) Optimized NTRU lattice parameters via quantum lattice entropy $H_Q(\Lambda)$; (4) Tightened NTRU-to-LWE reduction with polynomial-factor improvement. Theoretical results demonstrate significant security enhancement over existing constructions, providing implementable parameters for standardization.

cs.CR↗

arXiv2025

Towards Enhanced Quantum Resistance for RSA via Constrained R\'enyi Entropy Optimization: A Theoretical Framework for Backward-Compatible Cryptography

The advent of quantum computing poses a critical threat to RSA cryptography, as Shor's algorithm can factor integers in polynomial time. While post-quantum cryptography standards offer long-term solutions, their deployment faces significant compatibility and infrastructure challenges. This paper proposes the Constrained R\'enyi Entropy Optimization (CREO) framework, a mathematical approach to potentially enhance the quantum resistance of RSA while maintaining full backward compatibility. By constraining the proximity of RSA primes ($|p-q| < \gamma \sqrt{pq}$), CREO reduces the distinguishability of quantum states in Shor's algorithm, as quantified by R\'enyi entropy. Our analysis demonstrates that for a $k$-bit modulus with $\gamma = k^{-1/2+\epsilon}$, the number of quantum measurements required for reliable period extraction scales as $\Omega(k^{2+\epsilon})$, compared to $\mathcal{O}(k^3)$ for standard RSA under idealized assumptions. This represents a systematic increase in quantum resource requirements. The framework is supported by constructive existence proofs for such primes using prime gap theorems and establishes conceptual security connections to lattice-based problems. CREO provides a new research direction for exploring backward-compatible cryptographic enhancements during the extended transition to post-quantum standards, offering a mathematically grounded pathway to harden widely deployed RSA infrastructure without requiring immediate protocol or infrastructure replacement.

cs.CR↗

arXiv2025

Stark-Coleman Invariants and Quantum Lower Bounds: An Integrated Framework for Real Quadratic Fields

Class groups of real quadratic fields represent fundamental structures in algebraic number theory with significant computational implications. While Stark's conjecture establishes theoretical connections between special units and class group structures, explicit constructions have remained elusive, and precise quantum complexity bounds for class group computations are lacking. Here we establish an integrated framework defining Stark-Coleman invariants $\kappa_p(K) = \log_p \left( \frac{\varepsilon_{\mathrm{St},p}}{\sigma(\varepsilon_{\mathrm{St},p})} \right) \mod p^{\mathrm{ord}_p(\Delta_K)}$ through a synthesis of $p$-adic Hodge theory and extended Coleman integration. We prove these invariants classify class groups under the Generalized Riemann Hypothesis (GRH), resolving the isomorphism problem for discriminants $D > 10^{32}$. Furthermore, we demonstrate that this approach yields the quantum lower bound $\exp\left(\Omega\left(\frac{\log D}{(\log \log D)^2}\right)\right)$ for the class group discrete logarithm problem, improving upon previous bounds lacking explicit constants. Our results indicate that Stark units constrain the geometric organization of class groups, providing theoretical insight into computational complexity barriers.

math.NT↗