Posts to read for fun, like taking everything apart over a coffee to see what's inside, down to the deepest bolt. Come away understanding more, judging more clearly and deciding with a steadier hand.
What each layer of encryption (disk, database, single column) stops and doesn't stop. Envelope encryption with a KMS, key rotation, blind indexes for lookups, an experiment encrypting an email column in SQLite, and why SQL injection still reads encrypted data.
How to share a secret with a server you've never met. RSA and Diffie-Hellman by hand with small numbers, measuring RSA against Ed25519 for signing and verifying, equivalent key sizes, and the ML-KEM viet.sarl already uses against quantum computers.
If the database leaks, are the passwords still safe? Rainbow tables and salts, measuring SHA-256 at 4.3 million hashes/second against Argon2id at 44/second, estimating cracking time, a sign-in that doesn't reveal whether an email exists, and today's password policy.
The three properties of a hash function, why MD5 and SHA-1 were retired, collisions arriving early by the birthday paradox, measuring hash speeds, forging a sha256(key + data) signature with a length-extension attack, and comparisons that don't leak timing.
What security protects, what each of cryptography's three tools is for, why you don't hide the algorithm, and an experiment that predicts every output of random after seeing 624 numbers. The first post of the security series.