Can you crack the code? Come to this talk for a fascinating live demonstration of code-breaking through the ages. We won't just talk about how codes and ciphers get broken, or how they fail, we'll actually carry out the cracks live. From the ancient Spartans and Julius Caesar, through the ciphers of Blaise de Vigenere and Thomas Jefferson (a cryptographer more famous as the third President of the USA), right to modern cryptosystems such as WEP and SSL. Being interesting and entertaining is only a secondary goal of this talk. The primary goal is to convince you, by actions rather than by words (and without mentioning any products, honestly!), of two things: that encryption is worth doing, and that it is worth doing well.