About this site

I’m an engineer, somewhere in the middle-to-late part of my career. With AI to amplify what I can do in my spare time, I’ve been able to build the kind of learning material I always wished I’d had: explanations tailored to the questions I actually have, with figures I can poke at until the idea clicks. These pages are the result. They’re a companion to DSP Explorables, which does the same for signal processing, and CPU Explorables, for how a computer works.

Cryptography is new ground for me, so this site is a journey of learning in a way the others weren’t quite: I’m finding out alongside you.

How the pages work

Each page starts from the simplest idea that could work, shows where it falls short, and builds from there to the way things are really done. Every term is defined when it first appears, and every figure is live. Most pages include an attack you carry out yourself: breaking things is the best way to see why the real designs look the way they do.

Everything runs in your browser, on toy ciphers or on the pages’ own deliberately weak ones. They’re for understanding. Real software should use well-reviewed cryptographic libraries, never code like these figures’.

The pages are written and coded with Claude, Anthropic’s AI model, from my questions and outlines, and I review each one. The numbers in the captions are measured from the figures themselves, and the code behind them is tested, but mistakes are still possible. If you find one, I’d like to hear about it.

Who it’s for

I’m building these pages for myself, but I hope others find some use, and some joy, in them too. If they help you, that makes me very happy.