Comment Re:Encrypting Data at Motion, not Data at Rest (Score 2) 141
Encrypting data at rest doesn't get you much. Anyone who gets access to the backend gets access to the cryptographic keys used to read the data at rest.
This is the case whenever the attacker has access to the cryptographic endpoint. The fact is, as long as Google is one of the cryptographic endpoints, if you have access to Google's data, you have access to it regardless of whether you pretend to encrypt it. The only way you can significantly change that is to make yourself (that is, the person sending and the person receiving the e-mail) the cryptographic endpoint, so that Google only ever sees ciphertext.
But that's not very convenient.