By server mistrust, I mean the fully implemented lack of customer plaintext on a vendor's system, and lack of vendor access to customer plaintext.
Specific case in question: Password and SSH key management backups, in which all are AES encrypted before being sent off to the vendor.
- Vendor is compromised (pretty frequent, these days), e.g. by dumpster diving or disgruntled employees.
- Malicious actor deletes all vendor data.
- AES key used to encrypt backup is compromised.
Often, client-side data encryption just seems like a way to manage plausible deniability for the vendor in question, e.g. Mega.nz. Companies like the Clipperz password manager offer client-side encryption, or "mistrust" as a security feature.
I need a way to explain this sort of thing to management, users, and customers.
What security advantages does this sort of "you don't have to trust us" approach provide?
I am not asking about the security disadvantages, here, just the advantages.