This chapter focusses on Secure Key Exchange protocols executed among a group of parties, called group key exchange (GKE) protocols. Authentication and Key Establishment are very important in any secure communication. Authentication is generally based on long-term keys which can be associated with identities. To associate identities with long-term keys, we can assume the existence of a public-key infrastructure (PKI) which provides parties with some mechanisms for secure key registration and secure access to long-term keys of prospective peers. In most cases, there is also a need for some temporary keys. The Group Key Exchange protocols can be classified as Centralized, Distributed or Contributory. A few toolkits such as Spread and Cliques for the implementation of Group Key Exchange Protocols are also discussed.
Security of Group Key Exchange Protocols with Different Passwords
