Despite some weaknesses, the Kerberos and Secure RPC authentication mechanisms described in the previous section do much to prevent impersonation in a network environment. Note that Kerberos and Secure RPC only provide authentication services. Confidentiality and integrity services must be provided by other means. In this section, techniques for using Kerberos and Secure RPC to improve the authentication used by common network services are described. The description of these techniques is presented by means of examples of systems that are currently available.