dns over https

DNS over HTTPS (DoH) works by taking the traditional process of looking up a website’s IP address and wrapping it in the same encryption used for secure websites, making your DNS queries private and tamper-proof.

Here’s a step-by-step look at how it works in action, compared to the traditional DNS process:

Step	Traditional DNS (Insecure)	DNS over HTTPS (DoH)
1. Request Initiation	You type www.example.com into your browser. A plaintext DNS query is created.	You type www.example.com. Your browser or OS creates a DNS query and encrypts it as an HTTPS request.
2. Query Transport	The unencrypted query is sent over UDP/TCP port 53. It is visible to your ISP and anyone on the network.	The encrypted query is sent to a DoH server’s specific URL (e.g., https://dns.example/dns-query) over HTTPS port 443. It blends with other secure web traffic.
3. Resolution Path	Query goes to your ISP’s resolver, then through a hierarchy of root and authoritative servers to find the IP address.	The encrypted query goes directly to the DoH resolver (e.g., Cloudflare, Google). This resolver performs the lookup hierarchy on your behalf.
4. Response Return	The IP address (93.184.216.34) is sent back as a plaintext response, vulnerable to spoofing or alteration.	The DoH resolver encrypts the IP address answer inside an HTTPS response and sends it back.
5. Result	Your browser receives the IP and connects to the website. The entire query/response was exposed.	Your browser decrypts the response, obtains the IP, and connects. The query and destination were hidden from your local network.

🔧 Where and How DoH is Implemented

DoH can be activated at different levels, affecting what traffic on your device is protected:

• In Web Browsers: The most common method. Browsers like Firefox, Chrome, and Edge have built-in DoH settings. When enabled, only DNS queries from that specific browser are encrypted. Queries from other apps on your device still use traditional DNS unless the OS is configured.
• At the Operating System Level: Configuring DoH in your OS (like Windows 11 or macOS) encrypts all DNS queries from every application on the device, providing system-wide protection.

⚠️ Important Considerations

While DoH enhances privacy, its implementation has trade-offs:

• Security & Privacy vs. Visibility: The encryption that protects you from eavesdroppers also makes DNS traffic invisible to network security tools. This can bypass corporate web filters, parental controls, or security monitoring that rely on inspecting DNS queries. In enterprise settings, it’s often recommended to use an internal DoH resolver instead of public ones to maintain security policies.
• Centralization Concern: DoH can centralize DNS traffic with a few large public providers (like Google or Cloudflare), giving them broad visibility into browsing patterns, even though the traffic is encrypted between you and them.