Information Protection for the Domain Name System: Encryption and Minimization

This is the final in a multi-part series on cryptography and the Domain Name System (DNS). In previous posts in this series, I’ve discussed a number of applications of cryptography to the DNS, many of them related to the Domain Name System Security Extensions (DNSSEC). In this final blog post, I’ll turn attention to another application that may appear at first to be the most natural, though as it turns out, may not always be the most necessary: DNS encryption. (I’ve also written about DNS encryption as well as minimization…

Read More

Securing the DNS in a Post-Quantum World: Hash-Based Signatures and Synthesized Zone Signing Keys

This is the fifth in a multi-part series on cryptography and the Domain Name System (DNS). In my last article, I described efforts underway to standardize new cryptographic algorithms that are designed to be less vulnerable to potential future advances in quantum computing. I also reviewed operational challenges to be considered when adding new algorithms to the DNS Security Extensions (DNSSEC). In this post, I’ll look at hash-based signatures, a family of post-quantum algorithms that could be a good match for DNSSEC from the perspective of infrastructure stability. I’ll also…

Read More

Securing the DNS in a Post-Quantum World: New DNSSEC Algorithms on the Horizon

This is the fourth in a multi-part series on cryptography and the Domain Name System (DNS). One of the “key” questions cryptographers have been asking for the past decade or more is what to do about the potential future development of a large-scale quantum computer. If theory holds, a quantum computer could break established public-key algorithms including RSA and elliptic curve cryptography (ECC), building on Peter Shor’s groundbreaking result from 1994. This prospect has motivated research into new so-called “post-quantum” algorithms that are less vulnerable to quantum computing advances. These…

Read More

Newer Cryptographic Advances for the Domain Name System: NSEC5 and Tokenized Queries

This is the third in a multi-part blog series on cryptography and the Domain Name System (DNS). In my last post, I looked at what happens when a DNS query renders a “negative” response – i.e., when a domain name doesn’t exist. I then examined two cryptographic approaches to handling negative responses: NSEC and NSEC3. In this post, I will examine a third approach, NSEC5, and a related concept that protects client information, tokenized queries. The concepts I discuss below are topics we’ve studied in our long-term research program as…

Read More

Cryptographic Tools for Non-Existence in the Domain Name System: NSEC and NSEC3

This is the second in a multi-part blog series on cryptography and the Domain Name System (DNS). In my previous post, I described the first broad scale deployment of cryptography in the DNS, known as the Domain Name System Security Extensions (DNSSEC). I described how a name server can enable a requester to validate the correctness of a “positive” response to a query — when a queried domain name exists — by adding a digital signature to the DNS response returned. The designers of DNSSEC, as well as academic researchers,…

Read More