Turbo-Like Lattice Codes: Bridging Legacy Cryptography and Post-Quantum Secure Communication

This work introduces Turbo-Like Lattice codes, a novel communication architecture that integrates lattice-based cryptographic hardness with turbo-style iterative decoding. The design addresses the urgent migration challenge from RSA/ECC to post-quantum cryptography (PQC) by enabling secure, single-path, point-in-time delivery across hybrid quantum-classical channels. The architecture employs lattice-aware generator matrices, structured interleavers aligned to lattice geometry, pilot framing for synchronization, and compliance-ready decoding traces. Performance analysis demonstrates: Superior bit error rate (BER) resilience compared to classical turbo codes. Near-PQC throughput despite modest pilot overhead. Linear-time decoding complexity with bounded iterations and predictable resource use. These features ensure backward compatibility with legacy infrastructures, resilience against quantum adversaries, and auditability for regulated environments. By bridging classical and quantum domains, Turbo-Like Lattice codes establish a practical, patentable, and academically citable pathway for secure communication.