Protecting Assemblies
 

Is their any way to protect my .net assemblies (e.g. licensing module) from other peoples applications>

I wasn't entirely sure what you were referring to but there are a couple things you can do to secure your assembly.

1. StrongName your assemblies(sign with a key)
2. Use CAS(code access security) on either the assembly level or method level

to strongname the assembly you can do this by right clicking the assembly, going to properties and its under the security tab. here you can import a key to use to sign the assembly.

as for the CAS stuff here's a tutorial
http://www.codeproject.com/dotnet/UB_CAS_NET.asp