Ramblings on IT and Security

Tag: PQC

Taking the FUD out of PQC

“But Mike… there is no FUD in Post-Quantum Cryptography.”

I’m glad you brought that up, because that’s exactly what this post is about.

When people hear the term Post-Quantum Cryptography (PQC), the conversation often goes in one of two directions. Some claim that quantum computers are still decades away and that there’s nothing to worry about. Others make it sound as if RSA will stop working sometime next Tuesday, neither view tells the whole story. The reality is far more interesting, and far more nuanced than many have you believe, Post-Quantum Cryptography isn’t about fear, uncertainty, or doubt. It’s about understanding the actual risks, separating scientific facts from headlines, and making informed architectural decisions based on evidence rather than speculation.

So, let’s take the FUD out of the discussion. In this blog, we’ll look at what current research actually tells us about quantum computers, why symmetric encryption such as AES is in a very different position than RSA and ECC, who is realistically capable of building a cryptographically relevant quantum computer, and why organizations should begin preparing today, even though the first machine capable of breaking modern public key cryptography is unlikely to appear in your local datacenter anytime soon. Because the real challenge isn’t that quantum computers are coming. The real challenge is making sure your organization is ready when they do.

Continue reading

How Merkle Tree Certificates Work

For more than 35 years, X.509 certificates have formed the foundation of digital trust on the Internet and in many organizations alike. From HTTPS and VPNs to enterprise authentication and code signing, the basic architecture has remained unchanged. As we enter the post-quantum era, however, it may not be the cryptographic algorithms that need the biggest overhaul, but the certificate model itself.

Imagine a Certificate Authority such as Let’s Encrypt issuing hundreds of millions of post-quantum certificates. Every one of those certificates now carries a digital signature that is significantly larger than today’s RSA or ECC signatures. Suddenly, TLS handshakes become larger, certificate chains consume more bandwidth, Certificate Transparency logs grow faster, and browsers have considerably more data to process. Everything just slows down.

The challenge is no longer whether post-quantum cryptography works. The challenge is whether the X.509 certificate architecture can continue to scale in a post-quantum world. This is exactly the problem that Merkle Tree Certificates (MTC) are designed to solve.

Continue reading

Windows Server 2025 and Post-Quantum PKI

Once upon a time, certificates were issued, systems trusted each other, smartcards authenticated users, VPNs connected remotely, web servers showed reassuring padlocks, and somewhere in a forgotten virtual machine or dusty rack server, a CA happily kept signing certificates while everyone collectively agreed not to touch it unless absolutely necessary. And to be fair, in most cases, that worked surprisingly well. Until suddenly… it didn’t.

Over the last few years, PKI has been pushed far beyond what many environments originally designed it for. Certificate usage exploded. Identity became the new security perimeter. TLS is everywhere. Code signing became critical. Zero Trust architectures increased certificate dependency. And now, on top of all that, the industry is preparing for something that used to sound like science fiction:

Post-Quantum Cryptography. (Insert some dramatic music)

During the recent Windows Server 2025 Summit sessions, Microsoft shared a major update on their Post-Quantum roadmap for Active Directory Certificate Services (AD CS), including the introduction of ML-DSA support in Windows Server 2025 and the first practical steps toward quantum-resilient PKI.

Continue reading

© 2026 Michael Waterman

Theme by Anders Noren — Up ↑