There's likely a couple of factors which could include these: * A breach to internal database level would, in the majority of systems mean the attacker already

There's likely a couple of factors which could include these: * A breach to internal database level would, in the majority of systems mean the attacker already has all the keys to use the database system * A database cannot perform a lot of its functionality (e.g. JOINs) without access to the data & if the encryption keys were usable at the database level to perform such functionality it would make the encryption redundant. A working 'encrypted database' system would likely need to use Hardware Security Modules (HSMs) to prevent key exfiltration, you would distribute these to people who need to use the database, who would need to decrypt it in mostly its entirety to use it. It's possible by reworking entirely how modern databases work (fully homomorphic encryption is probably useful here) you could create a system where the database doesn't have to already be fully decrypted for you to use it, but as far as I know it doesn't exist (startup idea?).