Post-quantum DNSSEC over UDP via QNAME-Based Fragmentation

Post-quantum DNSSEC over UDP via QNAME-Based Fragmentation

연구 분야: Cryptography

학회: International Conference on Security, Privacy, and Applied Cryptography Engineering

In a typical network, any DNS message exceeding the recommended size of 1232 bytes would 1) either be fragmented into several UDP/IP packets 2) or require a re-transmission over TCP. Unfortunately, IP fragmentation is considered unreliable and a non-trivial number of nameservers do not support TCP. With the advent of DNSSEC, this size constraint becomes even more pressing since DNS messages now additionally carry digital signatures (and in some cases, public keys as well). While signatures of classical schemes such as RSA and ECDSA are sufficiently small to avoid size concerns, their much larger post-quantum counterparts easily cause the DNSSEC message size to exceed 1232 bytes. Multiple fragmentation schemes at the application (DNS) layer have been proposed, with ARRF (CoRR’22) being the most recent, to address the problem of transmitting large DNS messages. In this paper, we propose a new DNS layer fragmentation solution for integrating post-quantum cryptography in DNSSEC over UDP. Our scheme, called QNAME-Based Fragmentation (QBF), can reconstruct the entire DNS message in just 1 round trip while using only standard DNS resource records. Our experiments show that in a simulated network of 10 ms latency, with an EDNS(0) buffer size of 1232 and Falcon-512 as the zone signing algorithm, a QBF-aware resolver and nameserver setup can resolve Type A DNSSEC queries in \(43 \pm 1\) ms, beating both standard DNS with TCP fallback (\(83 \pm 1\) ms) and parallel ARRF (\(63 \pm 1\) ms).