Re: Auto locking door lock with remote

["ambo22" <amyas.phillips@xxxxxxxxx>]

I agree it would be technically possible to train a big antenna on
someone unlocking their door and read off the 40 bit code, or, slightly
harder, to energise someone's key and read its response while its in
their pocket.  The question is, who would?  No random burglar is going
to do that, burglaries are mostly opportunistic.  A black-hat
RFID-trawler with a powerful antenna might scan crowds, but its
exceedingly unlikely they'd know what they'd got, let alone be able to
ID the holder of the keyfob and follow them home.  Only someone quite
technically competent and very determined to get into this particular
house would be able to mount this attack successfully, and even then
its likely that there are easier attack routes available, such as
breaking through a window.  This isn't a highly secure system, from
what we've heard, but its probably as good as most physically-keyed
locks.  iButton is more secure than traditional keys but doesn't offer
many benefits in terms of convenience.  I would suggest some kind of
active RFID solution with rolling codes or challenge-response might
solve the evesdropping problem, and give the user a longer range to
boot.  I'll look forward to seeing that.