YiJing Hash v2. 0: Upgrading to SL (2, Fₚ) for Provable Non-Abelian Security — A Cryptographic Hash Function with Physical Basis, Matrix DLP Hardness, and Quantum Resistance

YiJing Hash v2. 0 upgrades Layer 3 from Dihedral group D₈ (order 16) to SL (2, F₁27) (order 2, 048, 256), a 128, 016-fold increase. The 8 Posterior Heaven (Hou-Tian) Ba-Gua trigrams serve as 8 generator matrices of SL (2, F₁27). All 28 generator pairs are non-commuting. Security reduces to Matrix-DLP over SL (2, Fₚ) -- no known quantum sub-exponential algorithm (unlike ECDLP broken by Shor). Theorem 4 establishes security separation from Tillich-Zemor attack (prime field p=127 vs F₂ⁿ). 64-round SHA-256-compatible Feistel with SL2 fingerprints in message schedule and rounds. Empirical: avalanche 49. 1%, zero collisions/50k, chi2 p=0. 944. Classical 2¹28, quantum 2⁸5 security. Supersedes v1. 0 (doi: 10. 5281/zenodo. 20257027).