Providing supplemental authentication of a user based on hand gesture activity of a user with an application of a device after a user has completed a successful authentication challenge to initially access the device. Hand gesture activity of the user with the device is recorded during current use of an application of the device. The recorded hand gesture activity during current use of an application of the device is compared to previous recorded hand gesture activity during use of the same application of the device by an authorized user to provide a supplemental authentication of the user. When the recorded hand gesture activity does not match the previously recorded hand gesture activity during use of the same application, the use of the application on the device is halted and an additional authentication challenge requiring input from the user is presented to the user.