Passing on Your Passwords

I enjoyed Cory Doctorow’s column in the Guardian this week: When I’m dead, how will my loved ones break my password? All his computer files are protected with such powerful encryption that, without the appropriate passphrase, all his data would be lost forever if he suffered a tragic accident.
I confess that the solution he came up with – splitting the passphrase between two lawyers in different jurisdictions – left me slightly deflated.  Surely there is a more ingenious solution.
I was reminded of the story of Robert H. Thouless, a Cambridge Don, who attempted to send passwords from beyond the grave. In the late 1940s, he encrypted a message that could be deciphered via a passphrase.  His idea being that, once he died, he would attempt to communicate the passphrase back into the land of the living.  Success would offer proof for the existence of an afterlife.
Unfortunately, his experiment was tripped up by Moore’s Law and some pesky Computer Scientists cracked the code by means of trial and error.  The pass phrase was “Black Beauty”.
As well as lacking any sense of the fantastical, Cory’s lawyer-based solution also lacks romance too!  Whatever happened to the time honoured tradition of leaving enigmatic riddles and poems on treasure maps?  Leaving a trail of clues, just like in The Da Vinci Code, or Indiana Jones, or Red Rackham’s Treasure has a great advantage:  Although it might be relatively easy for your designated heirs to discover whatever message you have left for them, it is usually quite difficult for them to do it while you are alive.  All that rumaging through your personal files, or examining that self-portrait from an acute angle, attracts attention.  You would therefore be able to see them off at the pass, should they attempt to get their paws on your legacy (be it electronic keys, or real ones) before you’ve croaked.