iButton Crypto (Slightly off topic)

sen_ml@eccosys.com sen_ml@eccosys.com
Wed, 08 Mar 2000 13:05:00 +0900

mss> If you just have a pair of keys, then according to the known
mss> practices it is recommended to generate a revokation certificate
mss> as soon as you generate a key pair, correct?  So if you loose
mss> your iButton, you just issue (send our, whatever :) you
mss> revokation certificate, and everything is fine, right?  

if i understand you correctly, you are suggesting putting the secret
key unencrypted in the iButton.  assuming so, there is a non-zero time
period between when you lose your iButton and when you send the
revocation certificate out (plus how long it takes for people to
become aware of it -- it might be a while for various reasons).  at
least for me, that doesn't fall in the category of "everything is
fine" :-)

if you have dropped your iButton into the ocean somewhere, may be you
aren't too worried about someone abusing it.  if you only discover
your iButton to be missing one day, then you may not know how long it
has been missing.  also, if you remove (or someone else does w/o your
knowing) your iButton and let it out of your sight, then someone may
obtain the data from w/in w/o you knowing.  if the passphrase is the
only thing that is stored w/in, they still have to get the encrypted
secret key (as Werner mentioned) -- if the secret key is stored in
unencrypted form, then oops...

to be honest, i have not given the "use many keys" scenario much
thought yet.