Starting with Xamarin.Android 4.6.0, assemblies shipped by Xamarin will be signed with a Xamarin key. Prior to this release, the assemblies were either not signed or only delay-signed. This change affects the strongnames of some Xamarin assemblies (Microsoft compatible assemblies strongnames remain unchanged).
Existing user assemblies linking to those assemblies (such as Mono.Android.dll) should be recompiled using Xamarin.Android 4.6.0 in order for them to work.
List of changed assemblies for Xamarin.Android
Before Xamarin.Android 4.6.0:
Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=c4c4237547e4b6cd
Mono.Android.Export, Version=0.0.0.0, Culture=neutral, PublicKeyToken=c4c4237547e4b6cd
Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=c4c4237547e4b6cd
Mono.Android.GoogleMaps, Version=0.0.0.0, Culture=neutral, PublicKeyToken=c4c4237547e4b6cd
Mono.Android.Support.v4, Version=0.0.0.0, Culture=neutral, PublicKeyToken=c4c4237547e4b6cd
Mono.Android.Support.v13, Version=0.0.0.0, Culture=neutral, PublicKeyToken=c4c4237547e4b6cd
OpenTK, Version=0.9.9.3, Culture=neutral, PublicKeyToken=c4c4237547e4b6cd
OpenTK-1.0, Version=1.0.0.0, Culture=neutral, PublicKeyToken=c4c4237547e4b6cd
Since Xamarin.Android 4.6.0:
Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065
Mono.Android.Export, Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065
Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065
Mono.Android.GoogleMaps, Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065
Mono.Android.Support.v4, Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065
Mono.Android.Support.v13, Version=0.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065
OpenTK, Version=0.9.9.3, Culture=neutral, PublicKeyToken=84e04ff9cfb79065
OpenTK-1.0, Version=1.0.0.0, Culture=neutral, PublicKeyToken=84e04ff9cfb79065
Note: this change removes some limitations when using InternalsVisibleToAttribute with Xamarin-shipped assemblies.