This practical textbook/guide is intended for academic courses in IT security and as a reference guide for Internet security. It describes important Internet standards in a language close to real-world cryptographic research and covers the essential cryptographic standards used on the Internet, from WLAN encryption to TLS and e-mail security. From academic and non-academic research, the book collects information about attacks on implementations of these standards (because these attacks are the main source of new insights into real-world cryptography). By summarizing all this in one place, this useful volume can highlight cross-influences in standards, as well as similarities in cryptographic constructions.