What is DNS over HTTPS (DoH)?

DNS-over-HTTPS is a relatively new technology that aims to keep your browsing private. There are some good things and some bad things about it, and whether or not you should use it depends on your personal preference. But before we dive into the complexities of the technology, we first have to establish what DNS-over-HTTPS is and how it can help (or hinder) you in the long run. Let’s find out.

What is DNS over HTTPS (DoH)?

In the late 1980s, the Internet Engineering Task Force (IETF) proposed the concept of DNS Over HTTPS because of the rise in malicious network attacks. Earlier, DNS queries between the web application and the servers of the DNS were done in plain text using the settings given by the network provider or ISP (Internet Service Provider).

The DoH aids the DNS queries by sending them guised as regular HTTPS traffic, but to special servers that support DoH. The server that supports DoH is called DoH resolver. In this, both the DNS request and response of that request are encrypted to keep the users’ privacy secured.

DoH is a network protocol used to communicate with domain name server information in an encrypted form over HTTPS traffic. It uses the hypertext transfer protocol secure to encrypt the DNS traffic bypassing the DNS queries, and it hides the DNS query and improves online privacy.

Popular DoH clients include Google Chrome, Mozilla Firefox, and Microsoft Edge. They support Doh and deploy DoH as well for data protection and privacy of users.

Standard DNS vs DNS over HTTPS (DoH)

Networks using standard DNS communications risk man-in-the-middle attacks if they don’t use a traffic filtering solution. This is because all DNS queries are written in plain text.

The DNS over HTTPS protocol uses built-in application HTTPS standards to encrypt queries. If hackers get access to your encrypted DNS queries, they won’t be able to read them. Your communications will still be private. DNS over HTTPS makes Man-in-the-middle attacks more or less useless.

Otherwise, the threat actor can see what domains you are trying to access. Additionally, activating the DoH hides the data within the enormous amount of HTTPS requests that pass through the network.

The difference between DNS over HTTPS (DoH) and DNS over HTTP is that the second one doesn’t use encryption.

How does DoH work?

Some name decryptions can be carried out directly from a user’s device. The corresponding information is shown in the cache of the browser or the router. Everything that has to be transmitted online usually passes through a UDP connection. This allows for a fast exchange of information. However, UDP is neither secure nor reliable. Data packets are regularly lost when using the protocol because there are no mechanisms that guarantee the transmission.

DoH, on the other hand, relies on HTTPS and, therefore, also on TCP – a protocol that is used much more frequently on the Internet. The advantages include encryption of connections and the protocol ensures a guaranteed transfer of data.

With DNS over HTTPS, communication always takes place via Port 443, which is where the actual web traffic is transmitted (e.g. accessing websites). Therefore, an outsider cannot differentiate between DNS requests and other communications. This introduces an additional level of user privacy.

Some benefits

• Hiding online activity. This is done by using a secure DNS service and encrypting all related traffic. Whenever a user enters a domain name into a browser, it makes a DNS query to transform the domain name into an IP address.
• Preventing DNS spoofing and man-in-the-middle attacks. If a browser and DNS server are in an encrypted session, then a malicious third party cannot manipulate the request results and direct the user to a fake website.
• Improving data security and privacy. If you set up DoH correctly, you will be able to increase data privacy and security in your organization.
• Testing. You can test how DoH connects to your networks in advance and fix any problems related to it before it becomes standard.

The Disadvantages of DNS over HTTPS

DNS over HTTPS isn’t perfect, however. For example, some website-blocking software will struggle with DNS over HTTPS if it depends on looking at the URL you’re visiting. This means that schools and parents will have more of an issue stopping kids from accessing dangerous and harmful content.

Also, because the DNS request has to go over HTTPS, it may take a little longer for your packet to go across the internet than if it used HTTP. However, there’s a good chance you’ll see no notable delay while using it.

Conclusion

Like any IT innovation, DNS over HTTPS did pose a few challenges at first, until everyone got aligned with it. Some might say it still is a challenge. However, once DoH became the standard, its benefits greatly outweighed the difficulties it once posed.

Integrating DoH with endpoint security makes maintaining effective DNS filtering possible despite the encryption of DNS traffic.