Authors - Amine El Ameri, Ahmed Drissi Abstract - Quantum computing threatens TLS through the Harvest Now, Decrypt Later (HNDL) attack: adversaries record encrypted traffic today and decrypt it once quantum capabilities mature. Existing approaches integrate post-quantum key encapsulation mechanisms directly into the TLS handshake; while cryptographically sound, they inflate the first handshake message and cause IP fragmentation of the ClientHello record that some middleboxes reject, leaving these solutions undeployable on today’s Internet. This paper proposes PH-PQ-TLS, a post-quantum key establishment framework for TLS 1.3 that adds post-quantum confidentiality while preserving the standard handshake, thereby avoiding fragmentation and middlebox incompatibilities. The framework requires no redesign of TLS, uses only standardized TLS mechanics, and is crypto-agile by design. We provide a full Go implementation and evaluate its overhead against a standard TLS 1.3 baseline. The ClientHello record measures 289 bytes, well below the minimum IPv6 Maximum Transmission Unit of 1280 bytes, whereas a hybrid ML-KEM-768 ClientHello reaches roughly 1473 bytes and exceeds that threshold. The post-handshake upgrade adds 1.18 ms of latency per full connection, a one-time cost amortized over the session lifetime and avoided on Pre-Shared Key resumed connections. These results show that HNDL protection does not require redesigning TLS, replacing the Web PKI, or accepting deployment failures, offering a practical, incremental path toward quantum-resilient TLS on today’s infrastructure.
Open Zoom