Re: storing an explicit nonce

> Yes, that's the direction that I was thinking also and specifically with
> XTS as the encryption algorithm to allow us to exclude the LSN but keep
> everything else, and to address the concern around the nonce/tweak/etc
> being the same sometimes across multiple writes.  Another thing to
> consider is if we want to encrypt zero'd page.  There was a point
> brought up that if we do then we are encrypting a fair bit of very
> predictable bytes and that's not great (though there's a fair bit about
> our pages that someone could quite possibly predict anyway based on
> table structures and such...).  I would think that if it's easy enough
> to not encrypt zero'd pages that we should avoid doing so.  Don't recall
> offhand which way zero'd pages were being handled already but thought it
> made sense to mention that as part of this discussion.

Yeah, I wanted to mention that.  I don't see any security difference
between fully-zero pages, pages with headers and no tuples, and pages
with headers and only a few tuples.  If any of those are insecure, they
all are.  Therefore, I don't see any reason to treat them differently.