Fundamental of Cryptography

Two strangers, an internet full of eavesdroppers, and a need to keep secrets. Cryptography is how. Hash functions, public-key magic, digital signatures, and the certificate machinery your browser trusts to load this page over HTTPS.

This topic closes the loop on lessons that already invoked crypto primitives in passing: the TLS handshake (Internet) and OAuth flow (Backend) both make a lot more sense once these building blocks click.