与其他 Internet 协议一样，DNS 可以通过VPN 和隧道运行。 DNS-over-Tor 自 2019 年以来已经变得足够普遍以保证其自己经常使用的首字母缩略词的一种用途。Oblivious DNS 的隐私效果可以通过使用预先存在的入口和出口节点的 Tor 网络以及 TLS 提供的传输层加密来获得。[7]
对于240多个国家代码顶级域名（ccTLDs），通常由该域名权威注册机构负责维护WHOIS。例如中国互联网络信息中心（China Internet Network Information Center）负责.CN域名的WHOIS维护，香港互聯網註冊管理有限公司（Hong Kong Internet Registration Corporation Limited）负责.HK域名的WHOIS维护，台灣網路資訊中心（Taiwan Network Information Center）负责.TW域名的WHOIS维护。
^（英文）P. Mockapetris.RFC 1035 - DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION: Page 32. 1987-11 [2018-04-24]. （原始内容存档于2011-02-12）.The Internet supports name server access using TCP [RFC-793] on server port 53 (decimal) as well as datagram access using UDP [RFC-768] on UDP port 53 (decimal).
^Csikor, Levente; Divakaran, Dinil Mon.Privacy of DNS-over-HTTPS: Requiem for a Dream?(PDF). National University of Singapore. February 2021 [2022-10-14]. （原始内容存档(PDF)于2023-03-15）.We investigate whether DoH traffic is distinguishable from encrypted Web traffic. To this end, we train a machine learning model to classify HTTPS traffic as either Web or DoH. With our DoH identification model in place, we show that an authoritarian ISP can identify ~97.4% of the DoH packets correctly while only misclassifying 1 in 10,000 Web packets.
^Posch, Maya.DNS-over-HTTPS is the Wrong Partial Solution. Hackaday. 21 October 2019 [2022-10-14]. （原始内容存档于2023-03-14）.DoH removes options for network operators (private and corporate) to secure their own network, as one of the architects behind DNS, Paul Vixie, pointed out on Twitter last year. DoH is essentially DNS-over-HTTP-over-TLS, resulting in its own mime Media Type of application/dns-message and significant added complexity. By mixing DoH in with existing protocols, it means that every DNS request and response goes through an HTTPS stack. For embedded applications this is a nightmare scenario, but it is also incompatible with nearly every piece of existing security hardware. When rogue apps like Firefox circumvent the system's DoT-based DNS and use its own DNS resolver over DoH instead, this makes for a highly opaque security situation. That DNS resolving would move into individual applications, as we see happening now, seems like a massive step backwards.
^Muffett, Alec."No Port 53, Who Dis?" A Year of DNS over HTTPS over Tor(PDF). Network and Distributed System Security Symposium. February 2021 [2022-10-14]. （原始内容存档(PDF)于2023-03-06）.DNS-over-HTTPS (DoH) obviates many but not all of the risks, and its transport protocol (i.e. HTTPS) raises concerns of privacy due to (e.g.) 'cookies.' The Tor Network exists to provide TCP circuits with some freedom from tracking, surveillance, and blocking. Thus: In combination with Tor, DoH, and the principle of "Don't Do That, Then" (DDTT) to mitigate request fingerprinting, I describe DNS over HTTPS over Tor (DoHoT).
