What actually makes a password strong: entropy, length, and why the old rules were wrong
The complexity rules everyone was taught optimized for the wrong thing. Here's how password strength really works, measured in bits.
Eternalsix Blog
Updates from the Eternalsix studio.
Unix timestamps, ISO 8601, and the timezone bugs that haunt every codebase
A number counting seconds since 1970 sounds simple. Here's why time is the hardest 'simple' thing in software — and how to stop getting it wrong.
UUIDs in practice: v4, v7, and choosing an ID scheme that scales
Random IDs you can generate anywhere, with no coordination — but the version you pick has real consequences for your database. Here's how to choose.
Hashing vs. encryption vs. encoding: a distinction worth getting right
Three words developers use interchangeably that mean completely different things. Confusing them causes real security bugs — here's the clean mental model.
Regular expressions for everyday developers
You don't need to memorize the whole grammar. A dozen constructs cover almost every regex you'll ever write — here they are, with the traps.
Base64, URL encoding, and percent-encoding: what each one is actually for
Three encodings developers mix up constantly. None of them is encryption — here's what each one solves and when to reach for it.
Cron expressions, field by field: a practical guide with real examples
Five little fields control almost every scheduled job on the internet. Here's how to read and write them without guessing.
How JSON Web Tokens actually work — and how to read one safely
A JWT is three base64 chunks and a signature. Here's what each part means, what it protects, and the mistakes that turn tokens into vulnerabilities.
JSON, demystified: formatting, validation, and the errors that trip everyone up
A working guide to reading, fixing, and trusting the JSON that flows through every API you touch.