A method comprises obtaining scan information by scanning a quick response QR code in a quick response key QRkey card, wherein the QR code includes a website link and a public key; opening a network platform page corresponding to the website link in the QR code; and obtaining a private key matching with the public key in the QR code and sending the private key to a user corresponding to the QRkey card, so that the user corresponding to the QRkey card can encrypt preset information by using the public key and decrypt the encrypted information by using the private key. A device comprises a first acquisition module, an open module and a second acquisition module. In the present invention a public key and a private key can be obtained by scanning a QR code in a QRkey card, thus a simple and convenient method for obtaining a key is provided.