Thread: Surprise Gift

Suppose u want to send a surpise gift to your friend.
U have a big box in which u can put that gift.
This box has a ring on which u can attach your lock.( Similarly like what u people have seen on a box where u put your locks).
The ring is big enough that many locks can be attached to it.
U hve many locks and every lock has a single key. ( Each lock has its own unique key)
But ur friend doesn't have duplicate keys for those locks. (neither the lock keys can be duplicated or a new key can be made from lock).

Now the problem is u hve to send ur gift in that box ( locked) to ur friend. Bt u cannot send the keys.

How will u do dat?