What is the key distribution mechanism in key lifecycle management?

The key distribution mechanism in key lifecycle management refers to the secure and controlled process of sharing cryptographic keys between authorized entities while ensuring confidentiality, integrity, and authenticity. This mechanism is critical to prevent unauthorized access or key compromise during transmission or storage.

Common approaches include:

1. Key Encryption Keys (KEKs): A master key encrypts other keys before distribution, ensuring only holders of the KEK can decrypt and use them.
2. Public Key Infrastructure (PKI): Asymmetric cryptography (e.g., RSA, ECC) allows secure key exchange via public-private key pairs. For example, a server shares its public key, while the private key remains secret.
3. Key Distribution Centers (KDCs): A trusted third party (e.g., Kerberos) authenticates users and distributes session keys securely.

In cloud environments, Tencent Cloud offers Key Management Service (KMS) to automate key distribution. It integrates with other services like COS (Cloud Object Storage) to encrypt data, ensuring keys are securely delivered to authorized applications or users via TLS-encrypted channels and role-based access control (RBAC). For instance, a user can request a data encryption key (DEK) from Tencent Cloud KMS, which is encrypted under a customer-managed CMK (Customer Master Key) and delivered securely for use.