Network Security

Networks are shared resources, and information that traverses them is potentially accessible to many other actors, who might seek to access sensitive information or modify it in harmful ways. Protecting the security and privacy of data and protecting end systems and network equipment from attacks have proven to be among the largest challenges to the Internet architecture. We discuss the threat model for networks and introduce some foundational building blocks of security: authentication, encryption, and key distribution. Security is very much a systems problem, so we examine a number of systems that provide a range of security capabilities, such as Kerberos and Transport Layer Security (TLS). Finally, because security and trust are closely related, we look at the potential for blockchain systems to be used as ways to decentralize trust.