Packages fields

[toad <matthew@toseland.f9.co.uk>]

Would it be possible to add an additional field per package in the Packages
file, which looks like this:
Freenet: CHK@L4mWBrou4o9RLhH71iew10zy4IAPAwI,sl3g1Cxz~xVOHb4w2SpNsA
(always exactly that length).
It is a hash of the file, distinct from MD5; Freenet can't use MD5 or any other
regular hash for various reasons. It can be determined without reference to
the network; it is several times slower than MD5. It would be very helpful for
apt-get-over-freenet. What would be involved in putting it in, is that even
possible? When is the MD5 field calculated (or checked) ? It only needs to be
in on actual distributed Packages files.
-- 
The road to Tycho is paved with good intentions