EU Exposure Notification Apps Can Finally Talk to Each Other

Updated: Nov 9, 2020

The recently launched EU interoperability framework lays the groundwork for cross-border exposure notification among its member states.





An EU-wide system to address the growing need for contact tracing to contain the COVID-19 pandemic went live on October 19, 2020. The system, a single European Federation Gateway Service, will allow digital contact tracing to be conducted across borders for app users travelling within a specified number of EU Member States. The following are the first national apps currently connected under this system: Germany’s Corona-Warn-App, Ireland’s COVID tracker, and Italy’s Immuni. Together, these three apps have approximately 30 million downloads, two-thirds of all app downloads in the EU. Czechia's eRouška, Denmark's Smitte|stop, Latvia's Apturi Covid, Spain's Radar COVID, and other European apps will join soon after.

Since the beginning of the COVID-19 pandemic, countries across the globe have sought contact tracing solutions to contain the novel coronavirus. While traditional manual contact tracing efforts are important, they require more resources than jurisdictions can muster. Especially as cases are rising again, digital contact tracing solutions, usually implemented using Bluetooth or GPS technology, can offer a more efficient and scalable solution that can go hand-in-hand with existing tracing, warning, and containment efforts. Mobile phone apps especially offer users an easy, accessible way of reporting and accessing COVID-19 related information.

A country, however, is likely to develop its own unique solution. If one EU country may use one back-end architecture while another EU country uses something else these two apps cannot talk to each other. If a mobile app user travels from Germany to Italy, they would need to install two different national apps. Now with the EU's interoperability gateway, however, users need only install and use one mobile app even while traveling across borders. As Thierry Breton, Commissioner for Single Market, recently stated, “Free movement is an integral part of the Single Market – gateway is facilitating this while helping save lives.” Under the interoperability infrastructure, users can automatically receive the appropriate COVID-19 alerts whether they are in their home country or abroad.

The European Commission first agreed upon interoperability guidelines in May and specified technical aspects in June. T-Systems and SAP developed and set up the system, which operates from the Commission’s data center in Luxembourg. The pilot phase launched soon after in September. The current system can only integrate apps that use the Google/Apple Exposure Notification API (GAEN). To start, compatible apps undergo “several tests and checks” before linking to the gateway architecture. According to the press release accompanying the guidelines, synchronization of various different back-end systems used by different countries requires exchanging only essential data – “No other information than arbitrary keys, generated by the apps, will be handled by the gateway: the information is pseudonymised, encrypted, kept to the minimum, and only stored as long as necessary to trace back infections” – fourteen days. The interoperability of the system still “does not allow the identification of individual persons, nor to track location or movement of devices,” clarified the press release.

Privacy and trust are priorities for any public health digital solution developed in the EU. Prior EU rules such as the General Data Protection Regulation (GDPR) and the ePrivacy Directive, in addition to the Commission’s stated commitment to privacy preservation, should allay citizen concerns about data protection, encourage app adoption, and feed into the large-scale, collaborative idea motivating the interoperability gateway. Vera Jourova, Vice-President for Values and Transparency, emphasized that “the European approach will be transparent and proportional” to the problem.

Technologists and academics have acknowledged the significant and necessary task of achieving interoperability at least since 1988. In 2006, the Association of Public Health Laboratories in the U.S. launched the Public Health Laboratory Interoperability Project, one of the first systems to facilitate the exchange of standardized public health data. The EU interoperability gateway’s launch, thus, is a significant step in that direction.

Most Member States have launched a COVID-19 app, with at least 20 of these compatible with the gateway system. For EU member states without a national app or with apps incompatible with the current interoperability architecture, however, a solution has yet to be reached. Further, broad app adoption is key to successful digital contact tracing. Beyond technological cooperation, EU members and other countries should continue to work together for complementary, non-technological tasks that increase citizen cooperation and trust to, in turn, hasten the pace of pandemic containment.



Further Readings


Lomas, N. (2020, September 14). Europe starts testing app interoperability service to power cross-border COVID-19 exposure alerts. TechCrunch.

Lomas, N. (2020, May 15). How will Europe's coronavirus contact-tracing apps work across borders?. TechCrunch.

Lomas, N. (2020, October 19). EU switches on cross-border interoperability for first batch of COVID-19 contacts tracing apps. TechCrunch.

European Commission. (2020, September 14). Coronavirus: Commission starts testing interoperability gateway service for national contact tracing and warning apps. European Commission.

European Commission. (2020, October 19). Coronavirus: EU interoperability gateway goes live, first contact tracing and warning apps linked to the system. European Commission.

European Commission. (2020, June 16). Coronavirus: Member States agree on an interoperability solution for mobile tracing and warning apps. European Commission.

European Commission. (2020). How tracing and warning Apps can help during the pandemic. European Commission.

European Commission. (2020, April 16). Coronavirus: Guidance to ensure full data protection standards of apps fighting the pandemic. European Commission.

eHealth Network. (2020, April 15). Mobile applications to support contact tracing in the EU’s fight against COVID-19: Common EU Toolbox for Member States. European Union.

eHealth Network. (2020, September 4). European Proximity Tracing: An Interoperability Architecture for contact tracing and warning apps. European Union.

European Commission, D.-G. for J. and C. (2020). Communication from the Commission Guidance on Apps supporting the fight against COVID 19 pandemic in relation to data protection. Official Journal of the European Union.

Olivi, G. (2020, September 29). COVID and privacy: fighting a pandemic through interoperability. JD Supra.

Noura, M., Atiquzzaman, M., & Gaedke, M. (2019). Interoperability in Internet of Things: Taxonomies and Open Challenges. Mobile Networks and Applications, 24(3), 796–809.

Association of Public Health Laboratories. (2020, July 17). Bringing COVID-19 exposure notification to the public health community. APHL Lab Blog.

Lo, B., & Sim, I. (2020). Ethical Framework for Assessing Manual and Digital Contact Tracing for COVID-19. Annals of Internal Medicine, M20-5834.