I did not investigate the legal situation in Australia or South Africa but
only wanted to give a hint that in some jurisdictions you might run into
trouble if you should ignore software-related patents despite the fact that
algorithms or "computer programs as such" are excluded from patent protection.
IDEA definitely isn't patented/covered in Australia and NZ. When someone
wanted to register it (meaning the IDEA implementation in PGP) with Ascom Tech
for personal use, they were told that it wasn't necessary because it wasn't
covered. This probably has more to do with the fact that they never bothered
filing for a patent here than our no-software-patents policy (claiming patent
rights for NZ probably doesn't rate very highly on a products feature list :-).
Peter.