[gebeeson]

At rest encryption would not prevent a breach from happening per se. The data the breach reveals however, maybe less than accessible due to the encryption. The data could be accessed but not easily read. That is the hope anyhow.

[cpitman]

This is assuming the breach is stealing a disk though, right? If the encrypted storage is part of an application, and I infiltrate the application or can trick it into serving me data, then the encryption cannot help. Any runtime breach isn't really prevented by encryption at rest.