It is misleading to speak of facial recognition in the singular: there are several different modes of operation, which do not all have the same impact on privacy.
In France, we are talking more and more about facial recognition technologies. The secretary of state for digital Cedric O, would like the law allows to conduct more experiments, while the National Commission of computing and freedoms (CNIL) published its "code of the road" in the matter .
Behind the term of "facial recognition" is hidden different technologies. Technically close to each other, they do not raise the same issues in terms of data protection and civil liberties at all.
The first and least important use of personal data protection is the verification of identity by comparing the image of a person with the one that is stored, for example in his passport. In this case, there is no constitution of a database, simply a comparison. It's the same mechanism that allows you to unlock some phones.
Technically, it's the most advanced facial recognition device. But as for all uses of this technology, the reliability of the device depends directly on the quality of the image taken as that to which it is compared.
It is also possible to compare the image of an individual with a previously constituted database, for example as part of a biometric security portal in a company that compares each person presenting to a base of persons authorized to enter in the walls of society.
The CNIL, responsible for the protection of personal data, is much more difficult in this case. The image of the face is indeed a biometric data: unlike a password, we can not change if the database is hacked! European law gives a very important protection to these data, described as "sensitive". To have the right to handle them, you need a very good reason (a security requirement for example), not having the possibility to use another technology, take drastic measures to secure the database …
It is also possible, in court proceedings, to use facial recognition: investigators can compare a photo (from a social network, a video surveillance …) to those contained in the file of treatment of antecedents the only one currently being able to be questioned for facial recognition.
At the other end of the spectrum, there is facial recognition on the fly, in the public space, coupled with video surveillance. Currently, this type of technology is not used in France, but could perhaps be used in the future. This is the most problematic use of facial recognition because it is done without the knowledge of passersby, and requires to work to process the biometric data – and potentially identify – of all people passing in the field of the camera. Some politicians, like Valerie Pecresse, president of the Ile-de-France region, claim it.
It is this mode of facial recognition that is, at the moment, the least reliable because the shooting is done in an environment called "uncontrolled" (with variations of light, orientation, low definition cameras , people on the move), which requires heavy treatment. However, machine learning technologies have made significant progress in recent years and it is this type of device that is deployed in some areas of China.