Clean riddles

cleanpoemssimplelogic

The front of me is the source of a song Or to kiss with a fervor of love lifelong. My back is a plant fit for a queen, Crafted by needle, chemical, or machine.
Necklace
67.76 %
105 votes
cleanfunnywhat am I

There was a green house. Inside the green house there was a white house. Inside the white house there was a red house. Inside the red house there were lots of babies. What am I?
This is a watermelon.
67.74 %
150 votes
logicsimpleclean

Suppose you want to send in the mail a valuable object to a friend. You have a box which is big enough to hold the object. The box has a locking ring which is large enough to have a lock attached and you have several locks with keys. However, your friend does not have the key to any lock that you have. You cannot send the key in an unlocked box since it may be stolen or copied. How do you send the valuable object, locked, to your friend - so it may be opened by your friend?
Send the box with valuable object and a lock attached and locked. Your friend attaches his or her own lock and sends the box back to you. You remove your lock and send it back to your friend. Your friend may then remove the lock she or he put on and open the box. Search: Man-in-the-middle attack
67.51 %
76 votes