A company is using a Redshift cluster as its data warehouse solution. There is a requirement from the Internal IT Security team to ensure that data gets encrypted at rest for the Redshift database. How can this be achieved?

Answer options:

A.Encrypt the EBS volumes of the underlying EC2 Instances.
B.Encrypt the Redshift cluster using AWS KMS Customer Master Key.
C.Use SSL/TLS for encrypting the data.
D.Use S3 Encryption.

Answer: B
Option A is incorrect because the requirement asks for encrypting the redshift database cluster and not the EBS of underlying EC2 machines.
Option B is CORRECT because Amazon Redshift uses a hierarchy of encryption keys to encrypt the database. You can use either AWS Key Management Service (AWS KMS) or a hardware security module (HSM) to manage the top-level encryption keys in this hierarchy.
Option C is incorrect because using SSL/TLS will encrypt the objects in transit but not objects at rest.
Option D is incorrect because S3 encryption is used only for objects in S3 buckets.
For more information on Redshift encryption, kindly refer to the following URL:
https://docs.aws.amazon.com/redshift/latest/mgmt/working-with-db-encryption.html