Here is the description from the manual document:
"Web.Config.EncryptionProvider
Base Description: The encryption provider used to encrypt the web.config. The allowed values are DataProtectionConfigurationProvider and RsaProtectedConfigurationProvider. Use RsaProtectedConfigurationProvider if you are running on a web farm. You will need to create an RSA key container before implementing the RSA encryption provider.
Default Value: DataProtectionConfigurationProvider
More Information:
"
I am doing it in a web farm. However I don't know how to create an RSA key container ? Please help ASAP. Thank you in advance.