An alternative to black out is to interpolate the pixels at the borders of the "blacked out" box. I've seen it done to suppress logos on images, in many cases i

An alternative to black out is to interpolate the pixels at the borders of the "blacked out" box. I've seen it done to suppress logos on images, in many cases it's barely intrusive. Applied to that QR-code, the currently blurred out part would be entirely white —because the original QR-code was surrounded by a white background. That should take care of many aesthetic concerns, without using a single bit of secret information for the final rendering.