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138 Stars 8 Forks Mozilla Public License 2.0 225 Commits 15 Opened issues


CoraLibre-android-sdk fork of prestandard DP-3T to make compatible with the Google/Apple protocol

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This code is based on the DP-3T prestandard android-sdk code. It aims to be compatible with the Apple/Google developed Privacy-Preserving Contact Tracing (PPCP) protocol. So far it is behaving more like DP-3T but we aim to transform it to be PPCP compatible. (We are making progress, the new CryptoModule seems to work right already.)

Note on development status

The development of CoraLibre is stalled. There is another implementation called CCTG, which does exactly what we what we where trying to achieve with this project. You can download CCTG from the F-Droid store.


This repository is based on prestandard DP-3T. With this project we aim to create a Privacy-Preserving Contact Tracing compatible SDK in order to create a libre alternative to the part of the Google Mobile Services that conducts the Bluetooth tracing.

The discussion about tasks that need to be done can be found in this thread. This SDK should become part of the CoraLibre app which should become compatible with the German Corona-Warn-App.


The Bluetooth specification as well as the cryptography specification is documented here:

The Android API is documented here:

Old DP-3T is documented here:

How to get started

So far everything is developed by Unit Testing. Before you can start make sure you know Android and are able to work with git(hub) repositories. Here are a few steps to "boot" you up into the project:

  1. First read the documents that are listed above in the documentation section.
  2. Clone this repository and read/run the unit tests. It will give you a good starting point about understanding the functionality of the SDK.
  3. When you have a good overview about the SDK take a look at the kanban board to see what is left to do or who is working on what already. If you have questions about each task read the corresponding issue or feel free to ask questions in there.


This project is licensed under the terms of the MPL 2 license. See the LICENSE file.

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