Right click in the window or click "File" to receive the print option.

Public key systems are often referred to as asymmetric or a two-key system. Encryption is done with one key while decryption is done with another. One key is kept secret and the other is publicly known. The keys are mathematically related in such a way that even if you have the public key, the private key cannot be deduced. This allows the public keys to be posted so that anyone can use your public key to encrypt information that only you will be able to decrypt using your private key.