Security
Advanced security topics and best practices for web protection
55 articles in this category
Code Signing Certificates Must Now Carry a Reserved Policy OID
From September 15, 2026, ballot CSC-32 requires every new code signing certificate to carry exactly one CA/Browser Forum reserved policy OID — 2.23.140.1.4.1 for non-EV, 2.23.140.1.3 for EV, 2.23.140.1.4.2 for timestamping. Why 'exactly one' does not mean one policy OID in total, why the EV value sits in a different arc of the tree and breaks prefix matching, how to read the extension with openssl or certutil, and why certificates you already hold need nothing done to them.
EV Domain Validation Reuse: The 398-Day Number Is Gone
Ballot SC102 passed on July 14, 2026 and deleted the hardcoded 398-day domain reuse period from the EV Guidelines, pointing section 3.2.2.14.3 at the Baseline Requirements instead. Why the number had already stopped applying in March 2026, the two reuse clocks an EV order now runs at different speeds, what happened to the WHOIS registrant re-check, and why the 10-day domain validation limit arriving in 2029 matters more than the 47-day certificate lifetime beside it.
NIS2 and Certificates: What the Directive Actually Requires of Your Encryption
Nothing in NIS2's risk-management article names TLS, a certificate type or a certificate lifetime — Article 21(2)(h) asks for policies and procedures on cryptography and stops there. Which of the four layers of rules actually binds you, why the binding technical detail in Regulation 2024/2690 only reaches digital infrastructure and trust service providers, what a cryptography policy has to contain, and the connection almost nobody makes: the Article 23(3) significance test is about impact rather than cause, so an expired certificate that takes a service down starts the same 24-hour reporting clock as an intrusion.
Secure Boot Certificate Expiration: What Changed in June, What Happens on October 19
Two of the three 2011 Secure Boot certificates have already expired — the KEK CA on June 24 and the third-party UEFI CA on June 27 — and the Windows Production PCA follows on October 19, 2026. None of it stops a PC booting, which is exactly why it gets under-reacted to: what expiry removes is the boot layer's ability to change, so no new boot manager, no new allow-list entry and no new revocation can reach a device that never received the 2023 replacements. Why the expired key exchange key is the one that actually closed the door, why three certificates are replaced by four, and the PowerShell check that tells you which devices are stuck.
Post-Quantum Code Signing: What You Can Actually Buy in 2026
No publicly trusted CA issues a post-quantum code signing certificate, and none can until the Code Signing Baseline Requirements change — the same forum opened that door for S/MIME back in August 2025. What ML-DSA, SLH-DSA and the stateful LMS and XMSS schemes each do, why signature size rather than compute is the migration cost, which of the three cryptographic parts of a signed file a quantum computer actually breaks, and what the October 19, 2026 Windows PCA expiry really asks of software vendors.
Root Certificate Expired? What Actually Breaks
Three separate events get called "the root expired", and only one of them turns a working certificate into a browser warning. Why a root passing its own expiry date is usually a chain-building problem with a five-minute fix, what really broke in 2020 and 2021, and the number that has quietly replaced the printed expiry date: both Mozilla and Chrome now schedule a root out of the trust stores about fifteen years after its key was generated, which for a 2010 root with a 2038 date on it lands thirteen years early.
Does the Cyber Resilience Act Require Code Signing?
Regulation (EU) 2024/2847 never mentions code signing, and every vendor selling you a certificate for it is describing one control out of a set. What Annex I actually asks for, why the September 2026 deadline has nothing to do with signing while the December 2027 one does, and the question the regulation never asks that decides whether you need a publicly trusted certificate or your own key. Plus the arithmetic nobody does: a five-year support period against a 460-day certificate.
ACME Challenge Types: Which One Your Setup Can Actually Use
Three challenges are in general use and a fourth is arriving, and the one you can pick is decided by your infrastructure rather than your preference. What http-01, dns-01, tls-alpn-01 and dns-persist-01 each demand, the redirect rules that make most HTTP-01 exception rules unnecessary, why multi-perspective validation broke setups that had worked for years, and why the domain-validation reuse window falling from 398 days to 10 by 2029 turns the challenge choice into an architectural one.
SSL Certificate Monitoring: What to Watch, and From Where
Monitoring a certificate means watching four different things, and most setups watch one. What your CA account, a Certificate Transparency log, the file on the host and a probe of the live endpoint each see — and what each one is blind to. Why the 200-day maximum in force since March 2026 moved the everyday failure from "nobody renewed it" to "it renewed and never reached the server", and why a fixed 30-day expiry warning stops meaning anything by 2029.
Certificate Pinning: What to Pin, and When Not To
A pin is a choice of height in the certificate chain, and that choice decides how often renewal becomes an outage. Why leaf pinning dies at every reissue while an SPKI pin survives if you reuse the key, what the shrinking lifetime schedule does to the arithmetic between now and 2029, how Android and Apple actually implement pinning, the backup-pin rotation order that does not break clients, and the two branches of the decision tree that end in "do not pin".
Code Signing Certificate Revoked: What Breaks and What to Do Next
Revocation is the one certificate operation nobody can undo, and it lands unevenly: one date recorded by the CA splits your release history into signatures that keep validating and signatures that stop. Which side each build falls on, why the reason you give changes the blast radius, what a customer actually sees when a revoked chain is rejected, and the order to recover in. Containment first, replacement certificate last, because that is the step that takes days.
Did AI Break AES? What Claude's HAWK and 7-Round AES Results Actually Mean
In July 2026 Anthropic reported that Claude Mythos Preview halved the effective key strength of the HAWK post-quantum signature candidate and sped up the best known attack on seven-round AES by 200–800x. Neither result touches a production system. Here is what was actually found, why it matters anyway, and what a TLS or code signing operator should do about it.