You can check it yourself with reverse engineering tools, e.g. on Android you could look at the APK with jadx and see the decompiled Signal implantation, and how it compares to the open source Java library from Signal…
You can check it yourself with reverse engineering tools, e.g. on Android you could look at the APK with jadx and see the decompiled Signal implantation, and how it compares to the open source Java library from Signal…