Re: storing an explicit nonce

On Sun, Sep  5, 2021 at 10:51:42PM +0800, Sasasu wrote:
> Hi, community,
> 
> It looks like we are still considering AES-CBC, AES-XTS, and AES-GCM(-SIV).
> I want to say something that we don't think about.
> 
> For AES-CBC, the IV should be not predictable. I think LSN or HASH(LSN,
> block number or something) is predictable. There are many CVE related to
> AES-CBC with a predictable IV.

The LSN would change every time the page is modified, so while the LSN
could be predicted, it would not be reused.  However, there is currently
no work being done on page-level encryption of Postgres.

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

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