Re: [Proposal] Table-level Transparent Data Encryption (TDE) and KeyManagement Service (KMS)

On Wed, Jul 10, 2019 at 12:38:02PM -0600, Ryan Lambert wrote:
> 
>     what is it that gets stored in the page for
>     decryption use, the nonce or the IV derived from it?
> 
> 
> I believe storing the IV is preferable and still secure per [1]: "The IV need
> not be secret"
> 
> Beyond needing the database oid, if every decrypt function has to regenerate
> the IV from the nonce that will affect performance.  I don't know how expensive
> the forward hash is but it won't be free.

Well, I think we have three options.  We have 3 4-byte integers
(pg_class.oid, LSN, page-number) that could be concatenated to be the
IV, we could run those through a hash, or we could run them through the
encryption function with the secret.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

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