The encrypted messaging app Signal has announced a new face blur tool that will integrate with the latest Android and iOS versions of the software.
Users who share images through the app can quickly blur faces and add another level of privacy to the images without completely hiding the identity of the subject.
In a blog post that announced the update, Moxie Marlinspike, co-founder of Signal, has linked the update to the worldwide protests against racism and police violence triggered by law enforcement officers' murder of George Floyd. These protests have resulted in downloads of signals that use end-to-end encryption to make it more difficult to intercept messages.
"We also worked on finding additional ways to support everyone on the street," Marlinspike writes. "One immediate thing seems clear: 2020 is a pretty good year to cover your face."
The blur tool is displayed in Signal's image editor.
When you take a picture via signal and select the Blur option in the toolbar, the app automatically detects all faces it detects in your picture. If something is missing, users can simply blur faces by hand or blur other features they want to hide. All processing is done on the device, meaning that uncensored images never leave the user's phone.
Although blurred faces in photos certainly make images more private, this is by no means a foolproof way to anonymize images and hide a person's identity. For example, some blurring and pixelation methods can be reversed with the right tools. And anyone who wants to identify someone in a picture can work with other information, such as clothing and tattoos, that can be compared to other, blurry pictures.
For example, even if participants in a protest hide the identity of other protesters, it does not mean that other groups and individuals are doing the same. Surveillance cameras, police cameras and press photographers capture images. Ultimately, the best way to hide your identity is to take matters into your own hands and wear a mask.