On Tue, May 25, 2021 at 04:29:08PM -0400, Stephen Frost wrote: > Greetings, > > On Tue, May 25, 2021 at 14:56 Bruce Momjian <br...@momjian.us> wrote: > > 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. > > > I’d like to review this more and make sure using the special space is possible > but if it is then it opens up a huge new possibility that we could use it for > both the nonce AND an appropriately sized tag, giving us integrity along with > encryption which would be a very significant additional feature. I’d > considered using a fork instead but having it on the page would be far better.
We already discussed that there are too many other ways to break system integrity that are not encrypted/integrity-checked, e.g., changes to clog. Do you disagree? -- Bruce Momjian <br...@momjian.us> https://momjian.us EDB https://enterprisedb.com If only the physical world exists, free will is an illusion.