Re: storing an explicit nonce

On Tue, May 25, 2021 at 02:25:21PM -0400, Robert Haas wrote:
> One question here is whether we're comfortable saying that the nonce
> is entirely constant. I wasn't sure about that. It seems possible to
> me that different encryption algorithms might want nonces of different
> sizes, either now or in the future. I am not a cryptographer, but that
> seemed like a bit of a limiting assumption. So Bharath and I decided
> to make the POC cater to a fully variable-size nonce rather than
> zero-or-some-constant. However, if the consensus is that
> zero-or-some-constant is better, fair enough! The patch can certainly
> be adjusted to cater to work that way.

A 16-byte nonce is sufficient for AES and I doubt we will need anything
stronger than AES256 anytime soon.  Making the nonce variable length
seems it is just adding complexity for little purpose. 

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  If only the physical world exists, free will is an illusion.