There are two new websites which explain how the privacy-friendly protocols of the corona tracing apps work:
This is a real nice "animation" for normal users showing all the steps of the process in an animated way. The animation focuses on what's going on from the view of the end users. There is a guided walkthrough to learn how to use the animation, or you can directly play with it.
The "protocol demonstration" goes deeper into the cryptographic part and shows exactly the messages created and exchanged. It's designed to bring out the protocol details behind from the view of the user Alice. There is a tour and a walkthrough which can guide you in different ways, or you can just interactively "play" with it.
Both websites implement the two major decentralized corona tracing protocols: "DP-3T" (Europe) and "Exposure Notification" (Apple/Google).
On the "protocol demonstration" website there are two tabs, "Description" and "Background", which contain further information and a comparison of the two protocols.
Both websites have been developed within the open-source project CrypTool (www.cryptool.org): The animation was done by a small group of young developers from Australia and Canada; the protocol demo was developed by a small German group. The two groups worked closely together and share the implemented algorithms in the background, but intentionally they present different experiences for different users.
- DP-3T on GitHub: https://github.com/DP-3T/documents
- Exposure Notification Documentation: https://www.apple.com/covid19/contacttracing/
There is also a video on the CT2 channel in YouTube introducing these two websites.