The European Union will start a trial with a digital corona passport in early June to make it easier for holders to travel within the EU. The underlying European system must be ready and operational by the end of June. The “Digital Green Certificate” will serve as proof that someone has been vaccinated, tested negative for corona, or has recovered from the virus. The evidence will be available in both digital and paper format and will contain a qr code to guarantee the authenticity of the evidence. The European Commission will build a gateway, just like with the corona apps, allowing national corona passports to be verified across the EU. The personal data of the holder does not go through this gateway (so no central database), only the information for the verification of the digital signature. Do you think this green certificate will work in full respect of the principles of effectiveness, necessity, proportionality and non-discrimination?