Google is testing Captcha queries via camera, users have to wave

Google is testing a new variant of its ReCaptcha service, which no longer only uses simple input or images to check whether a user is human. The system uses the front camera or a webcam to capture a range of features of a hand.

Google wants to see the hands

The Internet company Google has long operated its own service, reCAPTCHA, with which website operators can ask visitors to check requests that appear suspicious to ensure that it is not a bot. In order to improve bot checking, new methods are constantly being developed. Now Google taps into the camera of the respective client device. When the new camera-based Captcha query is triggered, the system activates the front camera of the respective smartphone and asks the user to wave their hand in front of the device or hold up their hand with an open palm. For the query, the browser also explicitly requests the user’s consent to access the camera.

Google evaluates video using a machine learning model

During the test, various features of the hand are recorded using a short video, which are then evaluated by a machine learning model based on 21 specific points. No audio data is captured during recording and Google provides input its documentation The MediaPipe technology on which the concept is based ensures that the videos are not linked to the identity of the respective user or passed on to third parties. If the camera-based Captcha check fails, for example because the user is unable to perform the required gestures, the well-known queries based on image or audio checks are used as a fallback.

The “camera captcha” is still optional and is in the testing phase. With regard to user privacy, using the front camera to test a user’s “humanity” is of course extremely problematic. It doesn’t matter whether Google adheres to its own data protection measures and does not link the videos to the users’ identities. In any case, the system doesn’t seem to be particularly reliable so far. So Testers have already been able to prove this which is very easy to trick using stock videos and screen recording software like OBS.