Client-Side Encryption with KMS Managed Keys, CSE-KMS. The encryption process is as follows. Using an AWS SDK, such as the Java client, a request is made to KMS for Data Keys that are generated from a specific CMK. This CMK is defined by providing the CMK-ID in the request. KMS will then generate two Data Keys from the specified CMK. One key will be a Plaintext Data Key. The second will be a Cipher blob of the same Data Key. Both keys are then sent back to the client. The client will then combine the Object Data with the Plaintext Data Key to create an encrypted version of the Object Data. The client then uploads both the encrypted Object Data and the Cipher blob version of the Data Key to S3. S3 will then store the encrypted Object Data and associate the Cipher blob Data Key as Metadata of the encrypted Object Data. The decryption process is as follows. A request is made by the client to S3 to retrieve the Object Data. S3 sends both the encrypted Object Data and the Cipher blob back to the client. Using an AWS SDK, such as the Java client, the Cipher blob Data Key is sent to KMS. KMS combines the Cipher blob Data Key with the corresponding CMK to produce the Plaintext Data Key. This Plaintext Data Key is then sent back to the client and the Plaintext Data Key is then used to decrypt the encrypted Object Data.