85 - Security Engineering
When I did my Masters in Science, I had to take a number of modules on topics that were wasted time (“Web Programming in XHTML and PHP” being my absolute favorite time and energy wasting exercise), but one module where I learned heaps and heaps was “Security Engineering”.
The course itself was so so (as - unfortunately most of the modules and courses that the University of Liverpool gave), but the book we were required to read was one of the best technical books I ever had the joy to read: Security Engineering: A Guide to Building Dependable Distributed Systems (Amazon.de) Security Engineering: A Guide to Building Dependable Distributed Systems (Amazon.com) It is a extremely accessible book, with load and loads of information presented in easy to read format, but with enough depth (and a fantastic list of sources)
Ross Anderson has a blog “Light Blue Touchpaper” where he announced, that the 2nd edition of his book is now free to download. Highly highly recommended reading for everyone with just a passing interest in security!