Does DNS over HTTPS hide from ISP?

Does DNS over HTTPS (DoH) Truly Hide Your Browsing from Your ISP? A Deeper Look.

The promise of DNS over HTTPS (DoH) is alluring: enhanced privacy by encrypting your DNS queries, shielding them from your Internet Service Provider (ISP) and other potential eavesdroppers. While DoH significantly improves your online security, the claim that it completely hides your browsing activity from your ISP requires nuance. Let’s delve into the realities of DoH and its impact on ISP visibility.

What DoH Does Hide:

DoH encrypts the DNS lookup process itself. Instead of your ISP seeing the raw, unencrypted domain name you’re requesting (e.g., www.example.com), they only observe encrypted traffic to a DoH server. This prevents them from directly building a profile of your browsing habits based solely on the websites you visit. This encryption also protects against DNS spoofing and man-in-the-middle attacks, which could redirect you to malicious websites. These are significant security improvements.

What DoH Doesn’t Hide:

While DoH masks the content of your DNS queries, it doesn’t conceal the fact that you’re making a DNS query, nor the volume of those queries. Your ISP still sees:

• The connection: Your ISP knows you’re connecting to a DoH server. They see the IP address of the server and the timing of the connection.
• The amount of data: While they can’t decipher the content, they can still observe the amount of data exchanged. A high volume of DoH traffic might still suggest significant browsing activity.
• Your IP address: Your ISP already knows your IP address. This remains unchanged by DoH. Through your IP address, they can still track your online activity, although with less precision than without DoH.
• Other network metadata: Things like the timing and frequency of your connections, and the overall patterns of your internet usage, remain visible.

The Practical Implications:

DoH makes it considerably harder for your ISP to build a detailed profile of your browsing habits. They can’t see the specific websites you visit, making targeted advertising and potentially intrusive monitoring significantly more difficult. However, they still possess considerable information about your online activity, albeit less granular.

Conclusion:

DoH offers a substantial leap forward in online privacy, significantly mitigating the risks associated with vulnerable DNS queries. It does not, however, provide complete anonymity. Your ISP still possesses contextual data about your online behavior. For comprehensive privacy, DoH should be considered one layer of a broader privacy strategy, including the use of a VPN, private browsing modes, and other privacy-enhancing tools. The effectiveness of DoH in protecting your privacy ultimately depends on your specific needs and risk tolerance. It’s a valuable tool, but not a silver bullet.