On Tue, Jun 13, 2017 at 01:01:32PM -0400, Stephen Frost wrote:
> > Well, usually the symetric key is stored using RSA and a symetric
> > cipher is used to encrypt/decrypt the data. I was thinking of a case
> > where you encrypt a row using a symetric key, then store RSA-encrypted
> > versions of the symetric key encrypted that only specific users could
> > decrypt and get the key to decrypt the data.
>
> This goes back to key management and I agree that it often makes sense
> to use RSA or similar to encrypt the symmetric key, and this approach
> would allow the user to do so. That doesn't actually give you a
> "write-only" encryption option though, since any user who can decrypt
> the symmetric key is able to use the symmetric key for both encryption
> and decryption, and someone who only has access to the RSA encryption
> key can't actually encrypt the data since they can't access the
> symmetric key.
I think the big win of Postgres doing the encryption is that the
user-visible file system is no longer a target (assuming OS permissions
are bypassed), while for file system encryption it is the storage device
that is encrypted.
My big question is how many times are the OS permissions bypassed in a
way that would also not expose the db clusters key or db data?
-- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB
http://enterprisedb.com
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