Michael Waterman

Ramblings on IT and Security

Month: June 2026

How Merkle Tree Certificates Work

June 27, 2026 / / 0 Comments

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.

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AD CS Performance Toolkit

June 15, 2026 / / 0 Comments

During many of the Active Directory Certificate Services (AD CS) projects I work on, the discussion always turns to performance. “So Mike, how to we need to scale the machines?” Is the virtual hardware powerful enough? Do we have sufficient memory? How many CPU cores should the Certification Authority have? Is our Hardware Security Module (HSM) fast enough? Will disk I/O become a bottleneck? And perhaps the simplest question of all:

How fast is Active Directory Certificate Services actually?

Another challenge I regularly encounter is the need for a realistic Certification Authority database. Whether demonstrating reporting capabilities, validating certificate templates, testing custom PowerShell scripts, or creating a representative lab environment, an empty CA database simply does not reflect production. After searching for a suitable solution, I realized that nothing really existed that combined realistic certificate generation with meaningful performance benchmarking. Existing tools either focused on enrollment or stress testing, but none provided detailed insight into where certificate issuance time was actually spent….so I built one.

The AD CS Benchmark & Performance Analysis Toolkit is a PowerShell-based utility that generates realistic PKCS#10 certificate requests, submits them through the native ICertRequest2 COM interface, optionally creates matching Active Directory objects, and records detailed timing information for every stage of the enrollment process.

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Building a Highly Available CRL and AIA Distribution Platform for AD CS

June 4, 2026 / / 0 Comments

Last time I wrote about the why a Certificate Revocation List (CRL) should be available for the majority of services that make use of certificates. One of those prime examples is the use of smartcards. When revocation can’t be checked, you simply can not logon. Most Microsoft PKI deployments start with a single web server hosting the CRL Distribution Point (CDP) and Authority Information Access (AIA) locations. While this works well for smaller environments or labs, it introduces a single point of failure. If the web server becomes unavailable, certificate revocation checking may fail and certificate validation can be disrupted across the environment.

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