Shooting for high-school-ish aged students who want to learn about cryptography, and are willing to learn about math and programming along the way.

• Introduction
  • what to expect, what we expect of you
  • encrypting punchlines with Reverse-Caesar codewheels
• Encoding information - Binary, ASCII, UTF-8, Morse code, Huffman encoding
  • each chapter begins with "what you'll get out of this chapter", which can also be "if you know all this, you can skim this chapter"
• Introduction to Cryptol
  • data types
  • sequences, comprehensions
  • functions
• Implementing the Caesar Cipher in Cryptol
• The Enigma
  • a bit of history
  • building one with paper
  • implementing the Enigma in Cryptol

I'm writing the book in ReStructuredText, and converting to PDF and HTML via Sphinx. (I switched from Pandoc/Markdown to make it easier to generate the index, and other improvements)