Who Is Using the Phone? Representation-Learning-Based Continuous Authentication on Smartphones

Table 1

Variable definition of MCBG.

Variable	Definition
	The ith actual touch’s position
	The ith target touch’s position
	The ith touch’s timestamp
	The ith touch’s pressure
	The ith touch’s contact area
	The ith touch’s long axis of the touch area
	The ith touch’s short axis of the touch area
acc, gyr, ori	Returned by the acceleration, gyroscope, and orientation sensor, including 3 floating numbers of 3 axes
down, move, up	Respectively denote pressing, moving, and lifting actions in the process of touching screens
	The ith touch record
	Average of s
	Total number of s
	Standard deviation of s
Skewness