On Wed, Feb 3, 2010 at 11:09 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Renegotiation after X amount of data is the recommended method AFAIK,
> because it limits the volume of data available to cryptanalysis.
> What makes you think that elapsed time is relevant at all?
>
> regards, tom lane
You are correct. In that volume of data also matters. It depends on
what kind of attack you are trying to minimize here. In my particular
use case I fluctuate between idle and busy but mostly low bandwidth.
You have four different primary cases that you are possible:
1) timed method on an idle link (or low usage)
2) timed method on a busy link (or high usage)
3) data limit on an idle link (or low usage)
4) data limit on a busy link (or high usage)
The timed method is more optimal for case 1.
The data limit is more optimal for case 4.
Case 2 gives an attacker more data to do crypto-analysis.
Case 3 gives an attacker more time to work with the current secret key
on a live link.
Depending on your use case, being able to work with a live link is
worse than working with the data postmortem. There is I'm sure some
hybrid in the middle between these where optimal lives.
Michael