To attach an EBS volume to an Amazon EC2 instance, both must be in the same Availability Zone.
Volumes that are created from encrypted snapshots are automatically encrypted using the same key as the snapshot. You can also use a different key that you specify.
Volumes that are created from unencrypted snapshots are automatically unencrypted, but you can encrypt these volumes.
If you don't see a volume that you created from an encrypted snapshot in the Volumes list, then you might not have the correct permissions.
A snapshot in an error state might indicate permissions issues.
Resolution
You can't directly share an encrypted EBS volume with another AWS account, so you must complete the following steps to share a volume.