PDoT

Abstract

Security and privacy of the Internet Domain Name System (DNS) have been longstanding concerns. Recently, there is a trend to protect DNS traffic using Transport Layer Security (TLS). However, at least two major issues remain: (1) How do clients authenticate DNS-over-TLS endpoints in a scalable and extensible manner? and (2) How can clients trust endpoints to behave as expected? In this article, we propose a novel Private DNS-over-TLS (PDoT) architecture. PDoT includes a DNS Recursive Resolver (RecRes) that operates within a Trusted Execution Environment. Using Remote Attestation, DNS clients can authenticate and receive strong assurance of trustworthiness of PDoT RecRes. We provide an open source proof-of-concept implementation of PDoT and experimentally demonstrate that its latency and throughput match that of the popular Unbound DNS-over-TLS resolver.