SHA-1 Is Shattered
In 2017 Google and CWI published two different PDFs with the same SHA-1 hash. The interesting part isn't that they did it — it's that everyone saw it coming for twelve years and the industry still waited for the proof.
Blog
Protocols, security incidents, and how the internet actually works. 147 posts.
Chrome Runs Its Own Root Store Now, and the OS Lost a Job
For most of its life Chrome trusted whatever the OS trusted. In September 2022 it began to stop asking — and in November 2024 it dropped a CA that Windows still trusted.
Your CA Now Decides When Your Certificate Renews
In 2020 Let's Encrypt faced revoking 3 million certificates with no way to tell their servers to renew. ACME Renewal Information — now RFC 9773 — hands the CA a dial on your schedule.
Certificate Transparency Runs on Static Files Now
For a decade, every TLS certificate was published to live, append-only cryptographic databases that had to merge each entry within 24 hours and answer queries around the clock. By early 2026 Let's Encrypt had replaced its own with folders of static files in a bucket. It's a better design.
How a Certificate Authority Dies
A CA doesn't usually die from a hack. Entrust died the modern way — from paperwork: late revocations, missed deadlines, and a browser root program that finally stopped believing the promises.
HPKP: The Security Header Too Dangerous to Keep
HTTP Public Key Pinning let any site pin its TLS keys in a header. It also let you permanently brick your own domain — or let an attacker hold it hostage. Browsers killed it.
Your Clock Is a Security Dependency
Certificate validity, HSTS, DNSSEC signatures, TOTP codes — a surprising amount of your security is really an assertion about what time it is. And the protocol that decides what time it is spent forty years believing whoever answered first.
ACME: How Certificate Issuance Became an API Call
ACME orders, domain challenges and renewal: choosing a validation route and checking that an issued certificate reaches the server.
A BGP Hijack Could Forge Your TLS Certificate. Now It's Harder.
For years, an attacker who could bend a BGP route near a certificate authority could pass its domain validation and get a real, browser-trusted cert for a domain they didn't own. In 2025 the industry finally made that much harder. Here's how MPIC works and what it doesn't fix.
Let's Encrypt Turned Off OCSP. Nobody Noticed.
In August 2025 the largest CA on the internet shut down its OCSP responders. Almost nothing broke — because online certificate revocation checking was already theater.
Encrypted Client Hello Hides Less Than You Think
ECH finally encrypts the one field HTTPS always leaked — the site name. But your IP, your DNS lookup, and the size of the crowd you hide in decide whether it means anything.
GREASE: The TLS Values That Mean Nothing on Purpose
Your browser offers servers a cipher that isn't a cipher and an extension that does nothing, billions of times a day. It's called GREASE, and it's the only thing keeping TLS able to change.