What is DNS over HTTPS (DoH) and why is it important?

DNS over HTTPS (DoH) is a protocol that encrypts DNS queries by sending them through the HTTPS protocol, providing enhanced security and privacy compared to traditional DNS. It prevents third parties from seeing which websites you're visiting by encrypting the DNS lookup process, which traditionally happens in plaintext. This technology is becoming increasingly important as concerns about online privacy grow, offering protection against eavesdropping, DNS hijacking, and man-in-the-middle attacks. By integrating DNS resolution within existing HTTPS traffic, DoH creates a more secure browsing experience for users without sacrificing performance.

Understanding DNS over HTTPS (DoH): The foundation of secure browsing

DNS over HTTPS represents a significant evolution in how our devices translate website names into IP addresses. Traditional Domain Name System (DNS) operates unencrypted, sending your browsing queries in plaintext that can be easily intercepted or manipulated. DoH changes this paradigm by wrapping these DNS queries within encrypted HTTPS connections.

Think of traditional DNS as sending a postcard with your browsing destination visible to anyone handling it, while DoH seals that request in a secure envelope that only the intended recipient can open. This fundamental shift addresses a long-standing security gap in internet infrastructure.

DoH works alongside existing IT infrastructure but enhances it with additional security layers. By encrypting DNS traffic, it prevents network operators, internet service providers, and potential attackers from monitoring which websites you're visiting. This protection extends across the entire network path from your device to the DNS resolver, ensuring that your digital footprint remains private throughout the journey.

How does DNS over HTTPS work?

DNS over HTTPS functions by sending DNS queries through an encrypted HTTPS connection to a compatible DNS resolver, rather than using plaintext UDP packets. When you type a website address into your browser, a DoH-enabled system will create an HTTPS request containing your DNS query, which is then sent to a DoH resolver over a secure TLS connection.

The technical process involves several key components:

• DNS resolver - A server configured to accept encrypted DNS queries over HTTPS
• Client application - Your browser or operating system that initiates the secure query
• HTTPS protocol - The secure channel through which DNS queries travel
• TLS encryption - The cryptographic method that protects the data in transit

When implementing DoH, the DNS query is formatted using either DNS wire format or as a JSON structure. The query travels through port 443 (the standard HTTPS port), which helps it blend with normal web traffic and bypass firewalls that might otherwise block alternative DNS protocols. Upon reaching the resolver, it processes the query and returns the encrypted response containing the IP address mapping.

Why is DNS over HTTPS important for data privacy?

DNS over HTTPS provides critical privacy protections by eliminating a major surveillance vector that has existed since the internet's early days. By encrypting DNS queries, DoH prevents ISPs from building profiles of your browsing activity, stops network administrators from monitoring specific website visits, and blocks malicious actors from intercepting your DNS traffic.

The privacy benefits extend to several key areas:

• Protection against ISP tracking and potential data selling
• Prevention of DNS hijacking attacks that redirect users to fraudulent sites
• Mitigation of man-in-the-middle attacks where attackers intercept and alter DNS responses
• Circumvention of DNS-based censorship in restrictive networks
• Reduction of data leakage that could expose sensitive browsing habits

For businesses, implementing DoH demonstrates a commitment to customer privacy and regulatory compliance. It adds another layer of protection for sensitive corporate data and helps prevent DNS-based attacks that could compromise security. This becomes increasingly important as privacy regulations worldwide continue to evolve and demand stronger data protection measures.

What are the differences between DNS over HTTPS and traditional DNS?

Traditional DNS and DNS over HTTPS differ significantly in their approach to security, performance, and implementation. The most fundamental distinction is that traditional DNS sends queries in plaintext, making them vulnerable to interception, while DoH encrypts queries, providing significantly enhanced privacy and security.

Traditional DNS has been the backbone of internet address resolution for decades, but its lack of privacy protections is increasingly problematic in today's security-conscious environment. While DoH may introduce slight performance overhead due to encryption, the privacy and security benefits generally outweigh these minor costs. Additionally, DoH can help bypass DNS-based filtering, though this can be either an advantage or disadvantage depending on your perspective and use case.

How can businesses implement DNS over HTTPS in their infrastructure?

Implementing DNS over HTTPS in your business infrastructure requires a thoughtful approach that balances security benefits with operational needs. For most organisations, implementation involves configuring both client devices and potentially your DNS infrastructure to support encrypted queries.

Start with these implementation steps:

1. Evaluate your current DNS infrastructure and identify components needing updates
2. Choose trusted DoH resolvers or consider setting up your own DoH server
3. Configure client browsers and operating systems to use DoH
4. Update network monitoring tools to maintain visibility despite encryption
5. Create policy documentation for your DoH implementation

When implementing DoH, be aware that it may impact existing security controls that rely on DNS monitoring. At Falconcloud, we recommend a gradual rollout starting with non-critical systems to identify any potential conflicts with security tools or performance issues. Our cloud infrastructure is fully compatible with DoH implementations, and we can provide guidance on maintaining security visibility while enhancing privacy through encrypted DNS.

For enterprise environments, consider implementing a hybrid approach where internal DNS queries use traditional methods while external queries leverage DoH for improved privacy. This maintains internal network visibility while protecting external browsing activity.

Key takeaways: Securing your digital presence with DNS over HTTPS

DNS over HTTPS represents a significant advancement in securing one of the internet's most fundamental processes. By implementing DoH, organisations can close a critical privacy gap in their security architecture while maintaining browsing performance and compatibility with modern web standards.

The most important considerations include:

• DoH significantly enhances privacy by preventing DNS snooping and manipulation
• Implementation requires planning to maintain security visibility and control
• The technology works best as part of a comprehensive security strategy
• Both client and server configurations may need adjustments for optimal performance

At Falconcloud, we support secure DNS implementations through our comprehensive networking infrastructure. Our Edge Gateways and Cloud VPN solutions integrate seamlessly with DoH deployments, ensuring your DNS traffic remains private without sacrificing performance or reliability. For businesses concerned about data privacy and security, implementing DoH represents a relatively straightforward enhancement that delivers significant privacy benefits across your entire digital footprint.