Wireless sensor networks have recently received a high level of attention due to their wide applications in military and civilian operations. This book discusses fundamental security issues in wireless sensor networks, techniques for the protection of such networks, as well as results from recent studies in wireless sensor network security. It includes a fairly new study on capabilities of mu-TESLA, a broadcast authentication technique for wireless sensor networks. This volume assists both professionals and students to understand background knowledge in wireless sensor network security and prepare them for producing research in this domain. The book is designed for a professional audience composed of researchers and practitioners in industry. It is also suitable as a secondary text for graduate-level students in computer science.