Disclosed is a method and an audio device system comprising at least a first device for transmitting and/or receiving audio over a first protocol, where the first device is configured for securely pairing with a second device, where the first device comprises a processor configured for: —generating a random passkey comprising a number of digits; —generating an image, where the digits of the random passkey is embedded in a challenge-response test image; —transmitting the image to the second device over a second protocol; and —pairing with the second device over the first protocol, when a first criterion related to the random passkey is satisfied.