Keypad against brute force attacks on smartphones

Although the powerful functions of smartphones provide much convenience for users, it causes a great damage because of loss and theft. Therefore the user has to use the phone lock provided by the smartphone. With the phone lock, the user is able to secure the time for requesting to stop the call service to the mobile telecommunication company and deleting the sensitive information with an anti-theft programme. However, the fixed keypad lock can be easily unlocked by brute force attacks and the pattern lock is vulnerable to smudge attacks. In this study, we propose a keypad for making brute force attacks and smudge attacks taking place on smartphones more difficult. The proposed keypad increases the time it takes for brute force attacks and is safe to smudge attacks. The smartphone equipped with the proposed keypad increases the time required for brute force attacks by the finder through formation of random buttons, random button arrangement and display delay time. Consequently, the smartphone owners are able to secure more time to become aware of the loss or theft and take action.