[OTR-dev] OMEMO, PFS

[Taylor R Campbell]

   Date: Tue, 10 Nov 2015 16:15:58 -0500
   From: Greg Troxel <gdt at ir.bbn.com>

   So it seems obvious that PFS is not a binary property; presumanbly the
   keys are overwritten (seems hard with flash wear leveling) when new
   messages happen, but there is a perhaps-months "short term key", vs a
   maybe-years "long term key", and PFS or not becomes blurry.

PFS is indeed not a binary property.  Aside from confusion arising
from the loaded word `perfect' in `perfect forward secrecy', some
people argue against using the term at all in favour of `key erasure',
and of stating when the relevant keys are erased.