Password security enhancement by characteristics of flick input with double stage C.V. filtering

Passwords for locking smart phones are usually exposed to the menace of shoulder surfing or smudge attacks. The passwords can be glanced at when being inputted since smart phones are usually used in a public space. Moreover, the whole characters of a password can be presumable, even if attacker does not look at the screen of a phone well since the arrangement of software keys is fixed and passwords are usually short. In this paper, we propose a method for enhancement of security of the password by applying characteristics of a person which can be captured in flick input. When the method is applied, the correct password is hard to be found by chance since attackers cannot distinguish rejection of wrong password from that of wrong characteristics. The method in this paper is an improved method in exiting papers. The method is applicable irrespective of the number of registered users.