What does Key Management mean?
Key management is the process of administering or managing cryptographic keys for a cryptosystem. It involves the generation, creation, protection, storage, exchange, replacement and use of said keys and with another type of security system built into large cryptosystems, enables selective restriction for certain keys.
In addition to access restriction, key management also involves the monitoring and recording of each key's access, use and context.
Techopedia explains Key Management
A critical cryptosystem component. key management is also one of the most challenging aspects of cryptography because it deals with many types of security liabilities beyond encryption, such as people and flawed policies. It also involves creating a corresponding system policy, user training, interdepartmental interactions and proper coordination.
For a multicast group, security is a large issue, as all group members have the ability to receive the multicast message. The solution is a multicast group key management system, in which specific keys are securely provided to each member. In this manner, an encryption using a specific member’s key means that the message can only be accessed and read by that group member.
A popular example of a key management systems is public key infrastructure (PKI), which is used in Secure Sockets Layer (SSL) and Transport Layer Security (TLS).