[SGVLUG] Security "riddle"

[bb.odenthal at gmail.com]

Hmmm.   You meet each other in person, verify who you are with two forms of I'd and exchange locks to which only the other party has the key.  I send the box to the other party locked with their lock and secret message inside.  The other party unlocks the lock to which they only have the key and responds by sending the box locked my lock.  

-bb
------Original Message------
From: Emerson, Tom (*IC)
Sender: sgvlug-bounces at sgvlug.net
To: 'SGVLUG Discussion List '
ReplyTo: SGVLUG Discussion List.
Subject: [SGVLUG] Security "riddle"
Sent: Nov 23, 2009 10:30

I came across this over the weekend - it was presented as a riddle on a page of riddles with non-obvious solutions [well, that is, if you don't know the answer - if you've seen the question before, chances are the answer will be "totally obvious", even if only because you were stumped before...]

So, here's the setup: you want to send someone something important/valuable/"secret", and you don't want anyone to intercept it.  You have a box with a lock on it, and the locking ring is big enough to hold more than one lock - you of course have several locks at your disposal, but you also have the *only* keys for the locks.

How do you lock the box such that the recipient can get what's inside without worrying about it getting stolen or intercepted in the mail?

Sending the key taped to the outside is, of course, not a recommended technique! ;)

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