Network security is concerned with creating a secure inter-connected network that is designed so that on the one hand, users cannot perform actions that they are not allowed to perform, but on the other hand, can perform the actions that they are allowed to. Network security not only involves specifying and implementing a security policy that describes access control, but also implementing an Intrusion Detection System as a tool for detecting attempted attacks or intrusions by crackers or automated attack tools and identifying security breaches such as incoming shellcode, viruses, worms, malware and trojan horses transmitted via a computer system or network.Today's computer infrastructure is exposed to several kinds of security threats ranging from virus attacks, unauthorized data access, sniffing and password cracking. Understanding network vulnerabilities in order to protect networks from external and internal threats is vital to the world's economy and should be given the highest priority. Computer and network security involves many important and complicated issues and this gathering of scientists will help not only in raising awareness but also in teaching participants the state-of-the-art of security techniques. Topics in network security, information security and coding are discussed in this volume.