Android: can I protect an app portion with a signature-level permission that is defined in another app with a different signature? -

let's assume android app app1 declares following permission:

<permission android:name="unipd.elia.delta.delta_service_manager"     android:description="@string/startdeltaservicepermission_description"     android:protectionlevel="signature"/> 

obviously, declaration means other apps signed same key app1 can use (acquire) permission.

however, question this: can app app2, signed different key app1, protect portion of permission? in other words, can app2 this:

<service android:name=".deltaloggingservice" android:process=":remote" android:exported="true"         android:permission="unipd.elia.delta.delta_service_manager" /> 

even if app2 not signed same key app1?

edit: in case ayone interested, real-world scenario this: app1 can interact other apps act plugins it, , want allow third parties develop new plugins can used app1. however, don't want apps other app1 (or app not developed me) interact such plugins.

well, while waiting answer had time test myself , yes, works.