This thread (Oct 11 2007, 02:23 PM) is still unsolved ??? Just chanced upon it today.
The solution is simple. you just form a chain using locks and the locking ring. If you open any lock, the chain is broken and the box opens
What makes you think it is unsolved?
Also, I don't see how your solution would work. If you make a "lock chain" out of your locks (all of which your friend doesn't have the keys for), then it really doesn't help. Also, if it's a "chain", isn't it possible to open up the box (slightly) and grab whatever is inside?