google
Release as a open source Chimera Module
The Exposure Notification Framework implementation is de facto closed source, locked inside a closed source component such as the Google Play Services Framework. It should at least be released as a Chimera module or give other ways to possibly implement it without the need of Play Services installed on the Android System.
Google and government worried about the decentral architecture of messaging w/o a connect mechanism to be abuse. E.g. by hacker or protesters says that is not a traceable communication way and we shall make everything in control including all possibilities and manageable.
@jixiangox: That does not apply here: Ensuring abuse prevention and conformance to national regulations is the primary task of each countries app. Sending invalid/cloned tokens is pretty easy even without the framework and is mostly prevented by frequent token rotation. Properly collecting all tokens and making them available to the country apps is much harder and is the exact code that google doesn't provide. Maybe Huawei will be more open on this, we'll see…
In current architecture, PHA App does not have the ability to do so but Google Play Service App as a closed source we dont have the direct access to hardware of RF because its shielded by this design then it will be integrated into OS in near future.
@jixiangox: Could you elaborate on why the PHA app wouldn't be able to access BLE and implement all of the exposure notification Bluetooth API and tracing itself? It would need to ask users for exceptions in Android and vendor battery saving features (foreground notification, background data exception, vendor/3rd-party task-killers exception) and most likely be banned from Google's Play Store for violating ToS, but I don't see why an Android app would not be able to do this in principle.