Oblivious DNS over HTTPS
As announced on our blog ↗, since late 2020, Cloudflare 1.1.1.1 supports Oblivious DNS over HTTPS (ODoH).
ODoH improves privacy by separating the contents of an HTTP request (and response) from its requester IP address. To achieve this, a proxy and a target are introduced between the client and the upstream DNS resolver:
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The proxy has no visibility into the DNS messages, with no ability to identify, read, or modify either the query being sent by the client or the answer being returned by the target.
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The target only has access to the encrypted query and the proxy's IP address, while not having visibility over the client's IP address.
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Only the intended target can read the content of the query and produce a response, which is also encrypted.
This means that, as long as the proxy and the target do not collude, no single entity can have access to both the DNS messages and the client IP address at the same time. Also, clients are in complete control of proxy and target selection.
Additionally, clients encrypt their query for the target using Hybrid Public Key Encryption (HPKE). A target's public key is obtained via DNS, where it is bundled into an HTTPS resource record and protected by DNSSEC.
Cloudflare 1.1.1.1 supports ODoH by acting as a target that can be reached at odoh.cloudflare-dns.com.
To make ODoH queries you can use open source clients such as dnscrypt-proxy ↗.
Also, iCloud Private Relay ↗ is based on ODoH and uses Cloudflare as one of their partners ↗.