You want to send a valuable object to a friend. You have a box which is large enough to contain the object and you also have several locks with keys. The box has an external locking ring and hasp which allows most normal padlocks to be used. But your friend does not have the key to any lock that you have. You cannot send a key in an unlocked box, since you are concerned that it might be copied. How do you send the valuable object?

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