I built a assembly which is a class library, for example lib.dll . And I also have a application to access this lib, for example test.exe. I changed the security permission for the test.exe to "intranet". At the same time, I want to change lib.dll to "Internet" like this: (Because I want to do some testing for security.) CasPol.exe -m -ag 1.2 -strong -file lib.dll lib 1.0.0.0 Internent But it seems the lib.dll can not get the security permission as I wanted. What is wrong with the command? Or maybe there are some other better solutions? Thanks -Jamebo