Method and system are provided for authentication for pairing of a smart pen with a computing device. The method, which is carried out at a smart pen, may include: sensing a signature event carried out by a user writing with the smart pen on an input user interface of the computing device; recording a signature resulting from the signature event; authenticating the signature by comparing to a stored previously recorded signature at the smart pen. If the authenticating is successful, the method activates connection of the smart pen with the computing device using a communication channel. A corresponding method is carried out at the computing device at which the signature event is carried out.