Thank you for your replies.
I've had a look at the StrongNameIdentityPermissionAttribute and I'm not sure if it is work correctly. I'll tell you what I've done and maybe you can tell me where I've gone wrong.
1) Create a class library and a strong name using sn.exe
2) Modified the AssemblyKeyFile attribute on the assembly to point to the strong name file.
3) Set DelaySign to false.
4) Got the public key using "sn -o" and removed the spaces an commas.
5) Places the result of "Step 4" in a StringNameIdentityPermission attribute on the assembly with a RequestMinimum.
6) Create a UI application that referenced this assembly and attempted to use a class. This generated a PolicyException.
7) I then signed the EXE with the same strong name, Steps 2 and 3, ran it again.
8) I still got the PolicyException message.
Can you tell me where I've gone wrong? The PolicyException states that the "Required Permissions Cannot Be Aquired".
Thank you,
Michael