This paper surveys key management for secure group communication. IP multicast is used to efficiently exchange messages among group members, but it lacks access control. Encryption is used to protect messages, but key distribution is challenging. Researchers have proposed three main approaches to group key management: centralized protocols, decentralized architectures, and distributed protocols. The paper surveys these approaches and classifies proposed solutions based on their characteristics. Centralized protocols use a single controller to manage the group, which can be a single point of failure. Decentralized architectures divide the group into subgroups managed by subgroup managers, reducing the risk of a single point of failure. Distributed protocols do not use a central controller, and members themselves generate keys. These protocols allow for more flexibility but may require more complex key management. The paper analyzes several protocols, including GKMP, Logical Key Hierarchy (LKH), One-way Function Tree (OFT), and Efficient Large-Group Key (ELK). These protocols aim to provide backward and forward secrecy, minimize key distribution overhead, and ensure secure key management. The paper also discusses other protocols such as Iolus, Dual-Encryption Protocol (DEP), MARKS, Cipher Sequences, Kronos, Intra-Domain Group Key Management (IGKMP), and Hydra. These protocols vary in their approach to key management, with some focusing on scalability, others on fault tolerance, and others on security. The paper concludes that hierarchical tree-based approaches are among the best solutions for group key management, as they achieve good results without compromising security. However, each protocol has its own trade-offs, and the choice of protocol depends on the specific requirements of the group communication system.This paper surveys key management for secure group communication. IP multicast is used to efficiently exchange messages among group members, but it lacks access control. Encryption is used to protect messages, but key distribution is challenging. Researchers have proposed three main approaches to group key management: centralized protocols, decentralized architectures, and distributed protocols. The paper surveys these approaches and classifies proposed solutions based on their characteristics. Centralized protocols use a single controller to manage the group, which can be a single point of failure. Decentralized architectures divide the group into subgroups managed by subgroup managers, reducing the risk of a single point of failure. Distributed protocols do not use a central controller, and members themselves generate keys. These protocols allow for more flexibility but may require more complex key management. The paper analyzes several protocols, including GKMP, Logical Key Hierarchy (LKH), One-way Function Tree (OFT), and Efficient Large-Group Key (ELK). These protocols aim to provide backward and forward secrecy, minimize key distribution overhead, and ensure secure key management. The paper also discusses other protocols such as Iolus, Dual-Encryption Protocol (DEP), MARKS, Cipher Sequences, Kronos, Intra-Domain Group Key Management (IGKMP), and Hydra. These protocols vary in their approach to key management, with some focusing on scalability, others on fault tolerance, and others on security. The paper concludes that hierarchical tree-based approaches are among the best solutions for group key management, as they achieve good results without compromising security. However, each protocol has its own trade-offs, and the choice of protocol depends on the specific requirements of the group communication system.