Fred C. Piper Quotes & Sayings

Step 1: The sender places the present in the briefcase, which they lock with their padlock and remove their key. They then send the locked briefcase to the receiver. Note: While the briefcase is en route from sender to receiver, it is safe from all adversaries, because they cannot remove the padlock from the briefcase. However, the receiver is also unable to obtain the present. Step 2: The receiver locks the briefcase with their own padlock and removes the key. They then return it to the sender. Note: The briefcase is now locked with two padlocks so no one can get the present. Step 3: The sender uses their own key to remove their padlock from the briefcase and returns the briefcase to the receiver. Note: The only lock on the briefcase belongs to the receiver. Step 4: The receiver removes their padlock from the briefcase to obtain the present. — Fred C. Piper