That basic a step is data encryption. It is one among many as we all know.
If you start out with database encrytion, there are several ways to go about it. It could be encryption of an application or encryption of file/disk space or encryption of the database itself by the authenticated person. There are negatives and positives to any method one chooses and it is important to understand them before implementing a solution.
Having a long-term vision in conjunction with other security measures such as access control and management, configuration, masking and understanding what is best for your organization can alleviate many of the security problems at a root level.