Technical notes on Linux, sysadmin, development and devops.
The CA/Browser Forum has approved a phased reduction of TLS certificate lifetimes down to 47 days by 2029. What changes, why, and why manual renewal no longer holds up.
What a brute force attack is, why every exposed service gets them, and the basic defenses: strong passwords and keys, multi-factor authentication, rate limiting, and tools like fail2ban.
The HTTP Deprecation header becomes an IETF standard: a machine-readable way to signal that an endpoint is being retired. What it is, how it works, and why it matters.
A reverse proxy explained in plain terms: an intermediary in front of your applications for TLS, caching, load balancing and security. The difference from a forward proxy, and why it's a common…
NIST has selected HQC as a backup post-quantum algorithm for encryption, built on different math than ML-KEM. What it is, the problem it addresses, and why having an alternative matters.
SPF, DKIM and DMARC explained in plain terms: who is allowed to send for a domain, the signature that proves integrity, and the rule for what to do when the checks fail.