When I took cryptography from Manuel Blum, he handed out copies of the chapter "Safecracker Meets Safecracker" from Richard Feynman's book Surely You're Joking Mr. Feynman. Feynman, the Nobel Prize winning physicist who was born a hundred years ago today, wrote this book not about physics but just a series of stories from different times in his life. This chapter described how Feynman learned how