Generates a unique data key. This operation returns a data key that is encrypted under a customer master key (CMK) that you specify. GenerateDataKeyWithoutPlaintext is identical to GenerateDataKey except that returns only the encrypted copy of the data key.
Like GenerateDataKey, GenerateDataKeyWithoutPlaintext returns a unique data key for each request. The bytes in the key are not related to the caller or CMK that is used to encrypt the data key.
This operation is useful for systems that need to encrypt data at some point, but not immediately. When you need to encrypt the data, you call the Decrypt operation on the encrypted copy of the key.
It‘s also useful in distributed systems with different levels of trust. For example, you might store encrypted data in containers. One component of your system creates new containers and stores an encrypted data key with each container. Then, a different component puts the data into the containers. That component first decrypts the data key, uses the plaintext data key to encrypt data, puts the encrypted data into the container, and then destroys the plaintext data key. In this system, the component that creates the containers never sees the plaintext data key.
The result of this operation varies with the key state of the CMK. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide.
GenerateDataKeyWithoutPlaintext & GenerateDataKey
原文：https://www.cnblogs.com/cloudrivers/p/11630639.html