Securing DNS Queries: A Comparative Guide to DoT and DoH

Two prominent options for securing DNS queries are DoT and DoH. In this comparative guide, we will delve into the differences, advantages, and use cases of both DoT and DoH to help you make informed decisions about which one to implement.

Suggested article: Full guide to DoT and DoH

What is DNS over TLS (DoT)?

DNS over TLS (DoT) is a secure DNS protocol that encrypts DNS queries and responses using the Transport Layer Security (TLS) protocol. When a device uses DoT, it establishes a secure connection to a DNS resolver, encrypting all DNS traffic between the user and the resolver. This encryption provides confidentiality and integrity, making it difficult for attackers to intercept or manipulate DNS queries and responses.

Advantages of DoT:

  • Strong Encryption: DoT uses TLS, which is a well-established and widely adopted encryption protocol providing strong security.
  • Improved Privacy: DoT hides DNS traffic from Internet Service Providers (ISPs) and other intermediaries, enhancing user privacy.
  • Authentication: TLS ensures the authenticity of the DNS resolver, reducing the risk of DNS spoofing attacks.
  • Standard Port: DoT uses a well-defined port (port 853), making it easy to deploy and manage.
  • Compatibility: It works at the system level, meaning all DNS queries, regardless of the application, can benefit from the security of DoT.

What is DNS over HTTPS (DoH)?

DNS over HTTPS (DoH) is another secure DNS protocol that encrypts DNS queries and responses but uses the HTTPS protocol, typically over port 443, for communication. When using DoH, DNS queries are sent as HTTPS requests to a DNS resolver that supports DoH, providing similar security benefits as DoT.

Advantages of DoH:

  • Firewall Bypass: DoH can bypass certain network restrictions and firewalls that might block traditional DNS traffic, enhancing accessibility.
  • User-Friendly: DoH can be implemented at the application level, allowing individual applications to choose their DNS resolver and giving users more control.
  • Widespread Adoption: Major web browsers like Firefox and Chrome have integrated DoH support, making it easily accessible to a broad user base.
  • Port Sharing: Since DoH uses port 443, it can coexist with other HTTPS traffic on the same port, simplifying network configurations.
  • Reduced ISP Snooping: Similar to DoT, DoH prevents ISPs from monitoring or intercepting DNS queries.

Comparing DoT and DoH:

Here are the main similarities and differences between DoT and DoH:

  • Security: Both DoT and DoH provide strong encryption and security, protecting against eavesdropping and data manipulation.
  • Privacy: DoT hides DNS traffic from ISPs, while DoH adds an extra layer of privacy by making DNS queries look like regular HTTPS traffic.
  • Ease of Deployment: DoT is easier to deploy at the network level because it uses a dedicated port. DoH can be configured at the application level, which might require additional effort.
  • Control: DoH offers more control to end-users and applications to select their DNS resolver, while DoT operates at the system level.
  • Adoption: DoH has gained wider adoption, especially through major web browsers, making it more accessible to average users.

Conclusion

Securing DNS queries is vital in today’s digital landscape, where privacy and security are paramount. Both DoT and DoH offer robust solutions to protect against manipulation of DNS traffic. The choice between them depends on your specific needs and infrastructure. Yet, both protocols play a crucial role in enhancing the security and privacy of DNS queries in an increasingly interconnected world.