EU Digital COVID Certificate
The EU Digital COVID Certificate ("EUDCC") was a digital proof that a person has either been vaccinated against COVID-19, received a negative test result, or recovered from COVID-19.
Background
The EUDCC was proposed by the European Commission in March 2021 as a response to the COVID-19 pandemic. The certificate was intended to facilitate safe travel within the European Union during the pandemic. After a political agreement in May 2021, the certificate was officially launched on July 1, 2021.
The project was eventually sunsetted in 2023, as the pandemic was declared over by the World Health Organization, and no countries had been issuing new certificates for over a year.
Technical Implementation
The EUDCC uses following technical components to ensure security and privacy:
- QR (Quick Response) codes for displaying the certificate
- zlib for compressing the data before encoding it in the QR code
- CBOR (Concise Binary Object Representation) for encoding the data comprising the QR code
- COSE (CBOR Object Signing and Encryption) for signing and encrypting data, ensuring integrity and authenticity
- JWKS (JSON Web Key Set) for managing and distributing keys for signing and encryption
The EUDCC was made as a decentralized system, meaning that the data was stored on the user's device and not in a central database. This was done to ensure privacy and security of the data. Multiple components existed in the system, and as the system was decentralized, the components were implemented by each country individually:
- Verifier App: Used by border control and other authorities to verify the EUDCC.
- Wallet App: Used by the user to store and display the EUDCC.
Open Source Projects in the EUDCC Ecosystem
The EUDCC specifications were built as open source projects, allowing anyone to implement the system. The following repository acts as an overview of the different projects in the EUDCC ecosystem: https://github.com/eu-digital-green-certificates/dgc-overview
Architecture
Implementations by country
🇩🇰 Denmark
In Denmark, the source code of the native Wallet App "Coronapas" has been published after the discontinuation of the EUDCC: https://github.com/Sundhedsdatastyrelsen/Coronapas.Mobile
🇩🇪 Germany
In Germany, the native Wallet App was called "CovPass". The solution, including issuer APIs, is source-available at: https://github.com/Digitaler-Impfnachweis