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Re: keeping secrets and knowing when they're compromised
> > I also want to know, if I'm still around, when and if those documents
> > are decrypted. I.e. In the event that my friend isn't as trustworthy
> > as I presume, I want to find out if s/he decrypts the files while I'm
> > still around.
There is a solution, a simple one, that can split the repsonsibility.
Encrypt the documents with a normal symmetric cryptosystem, something
strong and unlikely to be compromised in the near future, say LOKI or
IDEA, or maybe 3DES if you trust it.
XOR the key with a random value, give the result to your friend and print
out the random value, sign it and give it to a bank or solicitor as a
bequest in your will to your friend.
If and when something does happen the friend proves your death to the
bank using probate or a death certificate, gets the random value, XORs it
with the string you gave her and she has the key. She can then easily
decrypt the data.
Yes, it does involve a third party, but it is unlikely your friend could
collude with a respected bank or solicitor/notary to recover the key...
Really all depends how paranoid you are.
Datacomms Technologies data security
Paul Bradley, [email protected]
[email protected], [email protected]
Http://www.cryptography.home.ml.org/
Email for PGP public key, ID: FC76DA85
"Don`t forget to mount a scratch monkey"