c# - Understanding AppDomains and strong naming -

i'm trying create sandbox can load plugins. create appdomain , specify strongname host assembly, , understanding code running in assembly named runs in full trust. seems not case.

example,

static void main(string[] args) {     var permissions = new permissionset(permissionstate.none);     var setup = new appdomainsetup()         {             applicationbase = "c:\\temporary\\sandbox"         };      var domain = appdomain.createdomain("sandbox",                                         null,                                         setup,                                         permissions,                                         typeof (pluginhost).assembly.evidence.gethostevidence<strongname>());      var handle = activator.createinstancefrom(domain,                                                 typeof (pluginhost).assembly.manifestmodule.fullyqualifiedname,                                                 typeof (pluginhost).fullname);      var host = (pluginhost) handle.unwrap();     host.runplugin(); } 

pluginhost (defined in same assembly i'm strong naming),

public class pluginhost : marshalbyrefobject {     public void runplugin()     {         file.readalltext("c:\\passwords.txt");          var asm = assembly.loadfile(@"c:\plugins\unsafeplugin.dll");         var t = asm.gettype("unsafeplugin.fooplugin");          object plugin = activator.createinstance(t);         plugin.gettype().getmethod("run").invoke(plugin, null);     } } 

and plugin (residing in external assembly)

public class fooplugin {     public void run()     {         file.readalltext("c:\\passwords.txt");     } } 

i strong naming assembly containing pluginhost , therefore expect able read passwords file pluginhost , not fooplugin code throws securityexception when reading file (in pluginhost).

my understanding msdn documentation on subject fourth parameter containing strongname-instances give assemblies full trust in application domain.

from documentation:

"an array of strong names representing assemblies considered trusted in new application domain."

since proved myself wrong - how supposed work? why not in full trust though i've passed strongname appdomain.create?