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Guides
The reasoning behind the tools, sourced from NIST and IETF standards, not marketing copy.
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What Is a CSPRNG?
Why "random-looking" isn't the same as cryptographically secure, with a live demo and a real $100M+ example of what goes wrong.
UUID Versions Compared
v4 vs v5 vs v7 vs ULID vs NanoID: what each is actually for.
How TOTP Works
The algorithm behind your authenticator app's 6-digit codes, and why they sometimes don't match.
NIST's 2025 Password Rule Change
Length over complexity, no forced rotation, and mandatory breach screening: what actually changed.
How the Web Crypto API Works
What powers every generator on this site, and why it's trustworthy enough for real cryptographic keys.
SSH vs RSA vs PGP
RSA is the math. SSH and PGP are two different things built on it. Here's how they relate.
Password vs Passphrase
The entropy math behind both approaches, and when each one actually makes sense.