An archaeologist wishes to send a valuable artifact to a museum. However, he has doubts as to the integrity of the couriers, and fears they will keep the artifact for themselves if they get a chance to see it. He has a box, and a selection of locks and their keys, but he knows that the museum curator will not be able to open any of them. If he sends a key along with the box, the courier is sure to look inside.
What plan do he and the curator devise to ensure that the artifact is safely transported?
The archaeologist places the artifact inside the box and secures it with one of his locks. He sends it via courier to the museum curator, who attaches his own lock to the box and returns it. The archaeologist then removes his lock and sends it back. The curator can now remove his own lock and access the artifact.
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