Method and electronic device for determining whether to allow user access

Abstract

The disclosure relates to a method for determining whether to allow user access at an electronic device comprising: detecting a touch by an object on a touch-sensitive area of the electronic device, in which a plurality of electrode pairs are mounted, the plurality of electrode pairs including a first set of electrode pairs and a second set of electrode pairs; determining a subset of the first set of electrode pairs that are in contact with a part of the object; receiving electrical signals from each pair of the determined subset; calculating impedance values of respective parts of the object on the basis of the received electrical signals; determining a ratio of the calculated impedance values for each pair of electrode pairs disposed on mutually perpendicular lines from said the determined subset, and, when a first impedance value for one electrode pair included in electrode pairs disposed on the mutually perpendicular lines is greater than a second impedance value for the other electrode pair in the electrode pairs, the ratio of the calculated impedance values is a ratio of the first impedance to the second impedance; selecting two pairs of electrode pairs disposed on the mutually perpendicular lines with the maximum ratio of the calculated impedance values; and when the maximum ratio exceeds a predetermined threshold, identifying the object as a living tissue object, and allow access on the electronic device.