A terminal selectively and passively monitors for predefined wireless network discovery advertisements/requests. Requests that match what are expected by the terminal or requests that are in a predefined format are verified. The requests lack any connection pairing passcode; rather, the passcodes are separately provided from connecting devices only after the discovery requests are verified. The terminal independently authenticates the passcodes before authorizing wireless sessions between the devices and the terminal. Wireless discovery settings are continuously changed by the terminal and are valid for only a preset time window, each setting corresponds to a Time-based One Time Password (TOTP) representing a passcode; the TOTP is dependent on and valid only for the corresponding setting and the corresponding time window. In an embodiment, the connection requests are preauthorized by a server for a time window in the future, and the terminal authenticates the requests without interaction with the server.