Cwa-documentation: Travelling in other countries

[cvaldera]

What is missing

An explanation of what happens when someone goes to another country. Will the application interact only with other german mobile phones?
Should an international traveler install one application per country?

Why should it be included

Because there are people who travel a lot in different countries for personal / professional reasons

Where should it be included

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Internal Tracking ID: EXPOSUREAPP-2888

[aeisenbach]

This "roaming scenario" is being considered, but will not be part of the first release of the application.

[egandro]

This "roaming scenario" is being considered, but will not be part of the first release of the application.

How do you make sure, that we don't violate the law or foreign countries?

The tracking App might be illegal e.g. in Russia or Arabian countries.

[IXArcanumXI]

You have to make sure you don't break the laws in foreign countries @egandro . If Russia bans the app, it is your responsibility to deinstall it prior entering the country. Same story as "Blitzer-Apps" - might be legal if you use it in a foreign country - if you use it in Germany, it's your fault, not the developers fault.

[Leseratte10]

@egandro That is not the task for the developer. The developer is offering this software in Germany. If you use it and travel to another country, YOU are responsible for making sure that any app you use is legal in that country.

[Mikeichhalt]

Isn't every app that uses the Google/Apple Api compatible to each other by default?

[MikeJayDee]

Isn't every app that uses the Google/Apple Api compatible to each other by default?

Yes in one way: you can install several apps that can access the API. So if I travel from Germany to Denmark, I install the Danish app before I arrive in Denmark, and leave it installed for two weeks after my return to Germany. I will then get warned by the Danish about any contacts in Denmark that later had a positive test.

But also no in a sense: if I get infected and am infectious already in Denmark but only take a test in Germany, there will not be a simple way for the test result to be pushed to the Danish server.

[keugens]

... you can install several apps ...

Is there a good reason for that? Not that I know. Therefore, there is probably the effect that many potential virus spreaders will not participate.

[treysis]

This "roaming scenario" is being considered, but will not be part of the first release of the application.

If you don't implement the roaming scenario from the get-go - i.e. to have interoperable specifications - chances are it will only get more difficult downstream.

[LukasMasuch]

Cross-country interoperability is already worked on in collaboration with Apple/Google and many other countries. All apps that use the Exposure Notification API are already compatible at the Bluetooth level. To enable full interoperability, the diagnostic keys must be exchanged between national backends. Once a common API specification for key exchange is implemented, users won't need to install additional national apps when traveling in interoperable countries. This is currently work in progress, and additional information will be shared soon. In the meantime, DP3T's interoperability paper provides a good overview of this topic.

[keugens]

@LukasMasuch @SebastianWolf-SAP
It seems the paper you mentioned is protected against copy and print, which probably does not comply to the stated Apache Licence. Could you please clarify?

[raethlein]

@keugens Since it is an externally-linked document, I guess it does not fall under the Apache license of this repository.

[keugens]

Decentralized Proximity Tracing, Interoperability Specification; 18 May 2020; by DP3T
https://github.com/DP-3T/documents/blob/master/DP3T%20-%20Interoperability%20Decentralized%20Proximity%20Tracing%20Specification%20(Preview).pdf

Interoperability of decentralized proximity tracing systems across regions; 15 May 2020; by Accenture/Austria and others
https://drive.google.com/file/d/1mGfE7rMKNmc51TG4ceE9PHEggN8rHOXk/edit
Note: This document is protected against copy and print and probably cited wrongly as _DP3T's interoperability paper_ in this thread.

[LukasMasuch]

@keugens the DP3T team worked on two papers about interoperability: 1) A conceptual white paper written as a joint effort between DP3T and many other companies. You can find proof of DP3T involvement here or here. I don't know why it is currently protected against copy and print, but it is not under Apache 2.0 license since it is not an official document from the CWA project. 2) A technical specification that contains specific proposals for API and system design.

[amandadebler]

Will the app be available in non-German app stores? I'm a resident of Germany, but my phone is still connected to the US app store, because I need access to the apps for some US banks.

[kolAflash]

@LukasMasuch

Isn't every app that uses the Google/Apple Api compatible to each other by default?

Yes in one way: you can install several apps that can access the API. So if I travel from Germany to Denmark, I install the Danish app before I arrive in Denmark, and leave it installed for two weeks after my return to Germany. I will then get warned by the Danish about any contacts in Denmark that later had a positive test.

Are you sure that will work?
This issue looks different: corona-warn-app/cwa-documentation#329 _Incompatibility with the App Immuni_
Quote: _only 1 app can connect to their Exposure Notifications API on each device._
 

Cross-country interoperability is already worked on [...]

Can you tell what's the rough status of this?
Which countries have apps with possibly compatible architectures and which other app projects are you talking too?

Currently I only know two other apps which might be compatible:

• Italy (open source): https://github.com/immuni-app
• Denmark (closed source): https://smittestop.dk

As far as I heard the French app stores data centralizes and so it's incompatible (technically and regarding data protection policy).

[akuckartz]

This issue was raised 15 May 2020 - more than a month ago - and is still not resolved. Why not?

[cfritzsche]

I assume the reason is that european alignment is not quick to achieve. The european commission has just released its guidelines for interoperability a week ago: https://ec.europa.eu/health/sites/health/files/ehealth/docs/mobileapps_interoperabilityspecs_en.pdf

[MikeJayDee]

@LukasMasuch

Isn't every app that uses the Google/Apple Api compatible to each other by default?

Yes in one way: you can install several apps that can access the API. So if I travel from Germany to Denmark, I install the Danish app before I arrive in Denmark, and leave it installed for two weeks after my return to Germany. I will then get warned by the Danish about any contacts in Denmark that later had a positive test.

Are you sure that will work?
This issue looks different: corona-warn-app/cwa-documentation#329 _Incompatibility with the App Immuni_
Quote: _only 1 app can connect to their Exposure Notifications API on each device._

Yes and no. It turns out that only one app can be active at any point in time. If you have the German app active on one day, the Italian on the next and so on, you would still be warned from both (with an additional delay). When I wrote my original comment, the API was not yet published yet and there was no indication that only one app can be active at any point in time.

Which countries have apps with possibly compatible architectures and which other app projects are you talking too?

Currently I only know two other apps which might be compatible:

• Italy (open source): https://github.com/immuni-app
• Denmark (closed source): https://smittestop.dk

Out of my head, the following countries use the Exposure Notification API (probably not complete):

Active:
Latvia - Apturi Covid
Italy - Immuni
Switzerland - SwissCovid (Beta)
Denmark - Smittestop
Poland - ProteGO
Uruguay - Coronavirus-UY
Japan - COCOA

Announced (in no particular order, definitely not complete):
Ireland (possibly next week already)
Estonia
Austria
Spain
Portugal
Belgium
Netherlands
Canada (in July)
UK (only in late 2020)

As far as I heard the French app stores data centralizes and so it's incompatible (technically and regarding data protection policy).

[SebastianWolf-SAP]

Dear colleagues,

as already mentioned several times, cross-border interoperability will be worked on. Moreover, in https://github.com/corona-warn-app/cwa-documentation/issues/329 @sventuerpe mentioned the European interoperability guidelines (thanks for that!) - so things evolve in that area.

However, we can't give a concrete date when this will be addressed in Corona-Warn-App. Consequently, we will move this issue to this repository and allow the community and you to further refine or to discuss it.

The issue will move back to a development repository once the agreement with the contracting parties has been reached that it's due to be implemented shortly.

Best regards,
SW
Corona-Warn-App Open Source Team

[darkdragon-001]

One month later, people travel increasingly and come back home, infection numbers rise with home-comers being the primary source of such infections. What is the state?

[SebastianWolf-SAP]

The cross-border interoperability project is ongoing. However, there are no concrete release dates of a solution yet. As soon as we know something, there will be updates!

Mit freundlichen Grüßen/Best regards,
SW
Corona Warn-App Open Source Team

[zoellner]

Is there a list of other countries apps that are most likely to be compatible/will exchange keys first? I'm fine with a best estimate.
I'm asking to figure out which app I should start using since the German one is still not available in the US app store.
(I know I won't be able to contribute a positive test that way but at least I'd be able to retrieve exposure notifications)

[kbobrowski]

Perhaps a good idea would be to make risk estimation independent from "transmission risk levels" (or "infectiousness" in v1.5 API), like the app from Switzerland is doing (they just rely on weighted duration at attenuation). Then it would be possible to implement interoperability right away by fetching all DKs from other countries, verifying signatures, resigning with RKI key and pushing to the Telekom CDN - there would be no need for common approach on how to define "transmission risk levels" etc. and this could be implemented right away (and even one-sided, so without simultaneous implementation together with other country).

The disadvantage could be higher number of false-positives (if indeed precise mathematical accounting of TRL reduces false-positives), but perhaps it would be out-weighted by the benefit of being notified about the exposure which happened abroad, especially taking into account high number of imported cases.

Warn-App-Companion app already supports interoperability with other countries (as of version 1.3.0 - this will be soon pushed to Play Store) - perhaps similar mechanism could be implemented on the CWA backend. Warn-App-Companion currently supports:

• Austria
• Germany
• Poland
• Switzerland

This means that all the exposures registered in these countries will be displayed, even if someone had only CWA installed all the time when travelling. Or the other way around - if someone visits Germany from abroad, and keeps let's say SwissCovid running, a person with CWA and Warn-App-Companion running will also see this exposure, after infected person uploads keys to corresponding Swiss institution.

[ouboub]

Hi
I just wrote a couple of hours ago this:
Hi
https://www.zeit.de/digital/2020-09/kontaktverfolgung-corona-warn-app-ausland-eu
the test phase will start soon, but only for
Danemark, Tschechien, Italien, Lettland and Irland.
Spain is currently the country with highest increase of infections, and a considerable amount of death.
Spain is, moreover, a country that has attracted, at least in the past, the visit of a huge amount of German Tourists.

Spain is using a decentralized app, whose source code will be published soon.
The app does work (of sorts) however due to the political discussions
concerning competence of the autonomous regions it is not fully integrated in all regions but in some it is.

So why is Spain not included??
Could you name me please the persons in charge, that are responsible for this decision.
I will also try to find out whether there exist any similar forum for the Spanish app
kind regards

Uwe Brauer

[thomasaugsten]

The test phase starts with the country which are able to implement the connection to the EU gateway from their side at this time. Every EU country with an implemented connection can use the the gateway immediately. We have no influence on the implementation of the Spain app.

[Ein-Tim]

The EFGS is live for a bit of time now (available in App Versions 1.5.0 and above) and as of today, 10.11.2020, these countries are participating:

[dsarkar]

Dear @cvaldera,

Currently an increasing number of countries participate on the Transnational Exposure Logging. In this context, a comment on what happens if you use two Corona-Warn-Application using the ENF, but not (yet) participating in the Transnational Exposure Logging: https://github.com/corona-warn-app/cwa-app-ios/issues/1430#issuecomment-732080424

Best wishes,
DS

---

Corona-Warn-App Open Source Team

[dsarkar]

Dear @cvaldera,

I think your question is answered. I will close this issue now. Should you have more questions on this topic, please don't hesitate and re-open this issue. Thanks again for contributing.

Best regards,
DS

Corona-Warn-App Open Source Team

[MikeMcC399]

The FAQ https://www.coronawarn.app/en/faq/#interoperability_countries has been recently updated, and continues to be updated as more countries join into "Transnational Exposure Logging".

Also the Solution Architecture document in this repository includes a section Cross Border Interoperability.