In example embodiments, a first pattern of characters is displayed on a user interface of a user device. A user input is received and the first pattern of characters is replaced by a second pattern of characters. The user input is a selection of one of the characters from the pattern of characters. Each character is encrypted by a password selection rule (e.g., assign to a character selection the value of the character adjacent in a clockwise, counterclockwise, or diagonal direction from the selected character). After all user inputs are received determined from the password selection rule, an input password is generated. The generated input password is compared to a stored password designation to determine whether the input password matches the stored password designation. If the input password matches the stored password designation, the user is authorized to have access to the user device.