English: Asymmetric encryption with a public key and decryption with a private key can be illustrated with the following analogy: Public keys can be seen as open padlocks that can be distributed to anybody while the private key is the physical key to the padlocks. Once such a padlock is snapped close only the matching private key can unlock it. This allows anybody to put a message into a box and lock the box with the padlock. The sender can now be sure that only somebody who knows the private key can open the box and see the content.