{"ID":2885469,"CreatedAt":"2026-06-01T04:54:23.091178241Z","UpdatedAt":"2026-06-01T04:54:23.091178241Z","DeletedAt":null,"paper_url":"https://arxiv.org/abs/2508.19250","arxiv_id":"2508.19250","title":"Tight Quantum-Security Bounds and Parameter Optimization for SPHINCS+ and NTRU","abstract":"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 ($τ_d$) and parallelization limits; (2) Improved entropy concentration inequalities reducing SPHINCS+ parameters by 15-20\\%; (3) Optimized NTRU lattice parameters via quantum lattice entropy $H_Q(Λ)$; (4) Tightened NTRU-to-LWE reduction with polynomial-factor improvement. Theoretical results demonstrate significant security enhancement over existing constructions, providing implementable parameters for standardization.","short_abstract":"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 ($τ_d$) and parallel...","url_abs":"https://arxiv.org/abs/2508.19250","url_pdf":"https://arxiv.org/pdf/2508.19250v1","authors":"[\"Ruopengyu Xu\",\"Chenglian Liu\"]","published":"2025-08-06T00:15:21Z","proceeding":"cs.CR","tasks":"[\"cs.CR\",\"cs.DM\",\"math.NT\",\"quant-ph\"]","methods":"[]","has_code":false}