System 2.0.0.0 4.0.0.0 System.Enum This enumeration is used by the class. Indicates the security services requested for an authenticated stream. Field 2.0.0.0 4.0.0.0 System.Net.Security.ProtectionLevel Encrypt and sign data to help ensure the confidentiality and integrity of transmitted data. Field 2.0.0.0 4.0.0.0 System.Net.Security.ProtectionLevel Authentication only. Field 2.0.0.0 4.0.0.0 System.Net.Security.ProtectionLevel Sign data to help ensure the integrity of transmitted data.