I am having a debate with several people regarding how much protection full disk encryption provides.
dm-crypt is being used to encrypt data which is required by my company to be encrypted at rest. The Linux servers hosting the data reside in a secure data center with very little risk of unauthorized physical access, let alone someone actually stealing the server.
My argument is that in this situation, that while complying with the letter of the law, they have done little to nothing to actually reduce risk associated with unencrypted data. In effect, from a logical standpoint, they are in the exact same situation than if no encryption had been implemented at all. I am curious though if this train of though is correct, thoughts?
To tailor the question more to my specific situation, regarding physical protection, the controls around that are typically very sound. I am not saying risk is eliminated but it is considered to be low. Same with disposal of the drives, the destruction controls operate pretty effectively and risk is considered low. From a logical access standpoint the servers are not Internet facing, are behind a firewall, logical access is well controlled (but many have access), and they are not virtualized. Further, the servers operate 24x7, the only time they are rebooted is if it's needed after a change or during installation of a new one.
My concern is that in the event an insider goes rogue, or an unauthorized user exploits a logical security flaw, then the full data encryption does nothing to protect the data versus using some of the other field or file level encryption tools available. Whereas the people I am debating argue that this is not the case.