Abstract: A motion-based authentication method of authenticating a user with a mobile device is provided. A pre-training routine is conducted to detect an orientation characteristic and a duration characteristic associated with a user input. A training routine is conducted to capture a set of base signatures and to compute the consistency level associated with the signatures. A verification routine is conducted to compare the target signature with the set of base signatures. Authorization is granted if the target signature has reached the similarity threshold with respect to the base signatures.