surkar.in / learn

learn.

Notes, visualizations, and interactive explainers on things I find worth understanding deeply.

001
HMAC-SHA256
How Hash-based Message Authentication Codes work — step-by-step with live computation, XOR visualizations, and real intermediate values.
Cryptography →
002
Base64 Encoding
How 3 bytes become 4 characters — triplet-by-triplet bit visualization, the full alphabet, padding, and URL-safe variant explained.
Cryptography →