No abstract

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.

Simple password lock is usually used for smart phones in which significant information is managed although screen of smart phones is often exposed to the menace of shoulder surfing or smudge attacks. Some of the characters for the password is presumable when attackers did not gaze at the screen since the arrangement of software keys is fixed and passwords are usually short for convenience. Therefore, we proposed a method for enhancement of security of password lock for smart phones by applying the comparison of personal characteristics when passwords are inputted with flicks. However, in the proposed method, generated passwords tend to include the same character among different users since some specific characters can be stably inputted for all users. Moreover, passwords are mechanically decided by ignoring the intention of users. Furthermore, data in the research are evaluated without considering the floor shake. In this paper, we improve the method to solve the problems. Users can freely choose characters for passwords and the influence of the floor shake is absorbed by the new algorithm.