For new applications, security can be built-in. One method of building security into the application on z/OS® is to use z/OS System SSL and Kerberos. Another method is to use the Communication Server's policy-driven Application Transparent Transport Layer Security (AT-TLS), which requires no change to the application unless the application must control certain portions of the AT-TLS support.
Newer versions of network services, such as SNMPv3 and z/OS UNIX sendmail that are supported by the Communications Server, have security built into the application protocol using standards-based specifications for secure interoperability.