Tuesday, August 1, 2017

Puzzle with Solution

Secret Mail Puzzle

You want to send a secret message to your friend Alex in the mail.

But Sam, who you don't trust, has access to all your mail.

So you put your message in a box with a lock.

But you are not allowed to send a key!

How can you get your message through securely?


Solution to the puzzle:

Send the box with the lock to Alex. 

Alex can't open it, but can put another lock on the box. 

Alex sends this box with the 2 locks back to you, you 
unlock your lock and send it back to Alex again.

So there is just Alex's lock on the box and Alex can now open it.