On Tue, May 25, 2021 at 05:22:43PM -0400, Stephen Frost wrote: > * Bruce Momjian (br...@momjian.us) wrote: > > OK, this is good to know. I know the never-reuse rule, so it is good to > > know it can be relaxed for certain data without causing problems in > > other places. Should I modify my patch to do this? > > Err, to be clear, I was saying that we could exclude the hint bits > *entirely* from what's being encrypted and I don't think that would be a > huge issue. We still absolutely need to continue to implement a > never-reuse rule when it comes to nonces and making sure that we don't > encrypt different sets of data with the same key+nonce, it's just that > if we exclude the hint bits from encryption then we don't need to worry > about making sure to use a different nonce each time the hint bits > change- because they're no longer relevant.
So, let me ask --- I thought CTR basically took an encrypted stream of bits and XOR'ed them with the data. If that is true, then why are changing hint bits a problem? We already can see some of the bit stream by knowing some bytes of the page. I do think skipping encryption of just the hint bits is more complex, so I want to understand why if is needed. (This is a question I eventually wanted to discuss, just like my XXX questions.) -- Bruce Momjian <br...@momjian.us> https://momjian.us EDB https://enterprisedb.com If only the physical world exists, free will is an illusion.
