PQTLS-AD: Post-Quantum TLS Accelerated with DNS

Transport Layer Security (TLS) is expected to transition to Post-Quantum Cryptography (PQC) to mitigate the threats posed by quantum computing. While PQC ensures long-term security, it significantly increases the TLS handshake latency due to the larger key and signature sizes. Various solutions have been proposed to address this issue; however, they suffer from limitations, such as the necessity of pre-fetching certificates or dependency on prior connections. In this paper, we propose PQTLS-AD, a novel method that leverages the Domain Name System (DNS) to efficiently distribute PQC certificates. By offloading certificate transmission to DNS, PQTLS-AD reduces handshake data overhead, effectively lowering handshake latency. We have developed a PQTLS-AD prototype and conducted extensive experiments. Our results show that PQTLS-AD significantly reduces handshake latency, cutting it by more than one Round-Trip Time (RTT) compared to standard PQTLS.