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My third book, Hacking Secret Ciphers with Python, is finished. It is free to download under a Creative Commons license, and available for purchase as a physical book on Amazon for $25 (which qualifies it for free shipping). This is a book that is aimed at people who have no experience programming or with cryptography. The book goes through writing Python programs that not only implement several ciphers but also programs that can hack these ciphers.

http://inventwithpython.com/blog/2013/04/15/hacking-secret-ciphers-with-python-released/
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