What is an incorrect statement regarding Alibaba Cloud Key Management Service (KMS) concerning data encryption?

The statement asserting that the master key is kept by the user is incorrect because, in Alibaba Cloud's Key Management Service (KMS), the management of the master key is handled exclusively by KMS. This service is designed to securely manage cryptographic keys used for data encryption and decryption. By keeping the master key within KMS, it allows for enhanced security, as KMS provides a centralized solution for key management, including access controls and auditing.

KMS operates using a model known as envelope encryption, where data is encrypted with a data encryption key (DEK), which in turn is protected by a master key (the key managed by KMS). This process ensures that sensitive data remains secure while also allowing users to manage their encrypted data effectively.

The requirement for users to generate their own keys is also inaccurate in the context of the management of the master key within KMS, as users primarily utilize the service to create and manage cryptographic keys under the guidance of the system rather than entirely independently. This centralization of key management improves the overall security posture of applications using KMS for encryption.