A keyA number used to encrypt (or encode) information so that no one can read it. Keys are used when encoding and decoding. You shouldn't have to mess with keys yourself. that can be freely sent out in public, without being hidden. It works because it’s paired with a separate private keyA key that should be known only by your device and, possibly, by someone or something else that your device is communicating with. It must be kept secret. that’s needed for reading a message that was encryptedEncryption refers to encoding and decoding (or encrypting and decrypting) data so that it can't be read unless you have the right key. It's critical for good security. with the related public keyA key that you (or your device) can publicly share with someone or something else. This key can be used only to encode (or encrypt) data; it can't be used to read that data. Each public key has a matching private key, and the private key is used for decoding (or decrypting) data. This lets you have a secure conversation with someone or something that you've never shared keys with before..