In this book, we study the ID-based key agreement protocol from pairings, which contains two subjects: (1) ID-based mutual authentication and key exchange (ID-MAKE) protocol for mobile client-server environments, (2) ID-based authenticated group key exchange (ID-AGKE) protocol with resisting to malicious participants. In the first subject, we propose two secure ID-MAKE protocols. In the second subject, we first propose a security analysis of the previously presented ID-AGKE protocol. Then, two robust ID-AGKE protocols with resisting malicious participants are proposed. Finally, we provide formal security proofs to demonstrate that the proposed four protocols are provably secure.