Indicates whether the volume should be encrypted. Encrypted EBS volumes must be attached to instances that support Amazon EBS encryption. Volumes that are created from encrypted snapshots are automatically encrypted. There is no way to create an encrypted volume from an unencrypted snapshot or an unencrypted volume from an encrypted snapshot. For more information, see Amazon EBS Encryption (http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSEncryption.html) in the Amazon Elastic Compute Cloud User Guide.