Anyone with a computer has heard of viruses, had to deal with several, and has been struggling with spam, spyware, and disk crashes. This book is intended as a starting point for those familiar with basic concepts of computers and computations and who would like to extend their knowledge into the realm of computer and network security. Its comprehensive treatment of all the major areas of computer security aims to give readers a complete foundation in the field of Computer Security. Exercises are given throughout the book and are intended to strengthening the reader's knowledge - answers are also provided. Written in a clear, easy to understand style, aimed towards advanced undergraduates and non-experts who want to know about the security problems confronting them everyday. The technical level of the book is low and requires no mathematics, and only a basic concept of computers and computations. Foundations of Computer Security will be an invaluable tool for students and professionals alike.