试一试这种方法:
Importing and Exporting Protected Configuration RSA Key Containers
Protected configuration provides the capability to create, delete, export, and import RSA key containers when using the RsaProtectedConfigurationProvider. One scenario where this is useful is in a Web farm where the same encrypted Web.config file will be deployed to several servers. In that case, the same RSA key container must also be deployed to those servers. To accomplish this, you would create an RSA key container for the application, export it to an XML file, and import it on each server that needs to decrypt the encrypted Web.config file.
具体:
http://msdn.microsoft.com/en-us/library/yxw286t2%28VS.80%29.aspx