The Decentralised Privacy-Preserving Proximity Tracing (DP-3T) project is an open protocol for COVID-19 proximity tracing using Bluetooth Low Energy functionality on mobile devices that ensures personal data and computation stays entirely on an individual's phone. It was produced by a core team of over 25 scientists and academic researchers from across Europe. It has also been scrutinized and improved by the wider community.
DP-3T is a free-standing effort started at EPFL and ETHZ that produced this protocol and that is implementing it in an open-sourced app and server.
This is the first implementation of the DP-3T "low bandwidth" protocol. The current implementation does not use the as yet unreleased "Contact Tracing" API of Apple/Google--and has limitations as a result. Our "hybrid approach" uses Bluetooth Low Energy (BLE) to exchange EphID
s. It uses advertisements whenever possible and falls back to GATT Server connections if not possible to transmit/collect an EphID
this way (e.g., on iOS devices when the app is in background). This approach can result in higher energy consumption and scalability issues and will be replaced by the Apple/Google API.
Our immediate roadmap is: to support the Apple/Google wire protocol, to be forward-compatible, and to support the actual Apple/Google API as soon as it is released to iOS and Android devices.
- Android SDK & Calibration app: dp3t-sdk-android
- iOS SDK & Calibration app: dp3t-sdk-ios
- Android Demo App: dp3t-app-android
- iOS Demo App: dp3t-app-ios
- Backend SDK: dp3t-sdk-backend
The DP3T-SDK for Android contains alpha-quality code only and is not yet complete. It has not yet been reviewed or audited for security and compatibility. We are both continuing the development and have started a security review. This project is truly open-source and we welcome any feedback on the code regarding both the implementation and security aspects. This repository contains the open prototype SDK, so please focus your feedback for this repository on implementation issues.
The full set of documents for DP3T is at https://github.com/DP-3T/documents. Please refer to the technical documents and whitepapers for a description of the implementation.
A central discovery service is hosted on Github. This server provides the necessary information for the SDK to initialize itself. After the SDK loads the base url for its own backend, it will load the infected list from there, as well as post if a user is infected. This will also allow apps to fetch lists from other backend systems participating in this scheme and can handle roaming of users.
Included in this repository is a Calibration App that can run, debug and test the SDK directly without implementing it in a new app first. It collects additional data and stores it locally into a database to allow for tests with phones from different vendors. Various parameters of the SDK are exposed and can be changed at runtime. Additionally it provides an overview of how to use the SDK.
Name | Description | Function Name |
---|---|---|
initWithAppId | Initializes the SDK and configures it | public static void init(Context context, String appId) |
Name | Description | Function Name |
---|---|---|
start | Starts Bluetooth tracing | public static void start(Context context) |
stop | Stops Bluetooth tracing | public static void stop(Context context) |
sync | Pro-actively triggers sync with backend to refresh exposed list | public static void sync(Context context) |
status | Returns a TracingStatus-Object describing the current state. This contains: - numberOfHandshakes : int - advertising : boolean - receiving : boolean - wasContactExposed :boolean - lastSyncUpdate :long - errors (permission, bluetooth disabled, no network, ...) : List<ErrorState> |
public static TracingStatus getStatus(Context context) |
I was exposed | This method must be called upon positive test. | public static void sendIWasExposed(Context context, Date onset, ExposeeAuthData exposeeAuthData, CallbackListener<Void> callback) |
clearData | Removes all SDK related data (key and database) and de-initializes SDK | public static void clearData(Context context, Runnable onDeleteListener) |
Name | Description | Function Name |
---|---|---|
status update | Status was updated; new status can be fetched with the status method |
Register for Broadcast with the IntentFilter returned by public static IntentFilter getUpdateIntentFilter() |
To build an aar file that you can include in your project use in the folder dp3t-sdk:
$ ./gradlew assemble
The library is generated under sdk/build/outputs/aar
The SDK is available on JCenter and can be included directly as Gradle dependency:
dependencies {
implementation 'org.dpppt:dp3t-sdk-android:0.1.0'
}
In your Application.onCreate() you have to initialize the SDK with:
DP3T.init(getContext(), "com.example.your.app");
The provided app name has to be registered in the discovery service on Github
To start and stop tracing use
DP3T.start(getContext());
DP3T.stop(getContext());
Make sure that the user has the permission Manifest.permission.ACCESS_FINE_LOCATION granted (this coarse-grained permission is required for any app with Bluetooth activity; our SDK uses BLE beaconing but does not require any "location" data), Bluetooth is enabled and BatteryOptimization is disabled. BatteryOptimization can be checked with
PowerManager powerManager = (PowerManager) getContext().getSystemService(Context.POWER_SERVICE);
boolean batteryOptDeact = powerManager.isIgnoringBatteryOptimizations(getContext().getPackageName());
and for asking the user to disable the optimization use:
startActivity(new Intent(Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS,
Uri.parse("package:" + getContext().getPackageName())));
Tracing is automatically restarted if the phone is rebooted by the SDK, it is enough to call start()
once from your app.
The tracing happens in a foreground service and therefore displays a notification. This notification can be customized by defining the following string resources in your project:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="dp3t_sdk_service_notification_channel">@string/app_name</string>
<string name="dp3t_">@string/app_name</string>
<string name="dp3t_sdk_service_notification_text">@string/foreground_service_notification_text</string>
</resources>
To change the notification icon add your custom ic_handshakes drawable to the project.
TracingStatus status = DP3T.getStatus(getContext());
The TracingStatus object contains all information of the current tracing status.
To get notified when the status changes, you can register a broadcast receiver with
getContext().registerReceiver(broadcastReceiver, DP3T.getUpdateIntentFilter());
DP3T.sendIWasExposed(getContext(), null, new CallbackListener<Void>() {
@Override
public void onSuccess(Void response) {
}
@Override
public void onError(Throwable throwable) {
}
});
The SDK automatically registers a periodic Job to sync with the backend for new exposed users. If you want to trigger a sync manually (e.g., upon a push from your backend) you can use:
DP3T.sync(getContext());
Make sure you do not call this method on the UI thread, because it will perform the sync synchronously.
This project is licensed under the terms of the MPL 2 license. See the LICENSE file.