What Ford Focus models are affected by Hitag2 issue?

[justinhow]

Another story about poor vehicle security around keyless entry affecting many makes of cars https://www.theguardian.com/technology/2016/aug/12/cars-risk-keyless-entry-system-hacked-volkswagen including Ford's.

As far as Ford's (and most non VW's) are affected it appears to be those based on the Hitag2 transponder chip (see paper here) which has known problems.

So does anyone know if and what Focus models/years may be affected?