ICSF provides access to cryptographic functions through callable services, which are also known as verbs. A callable service is a routine that receives control using a CALL statement in an application language.

Prior to invoking callable services in an application program, you must link them into the application program. See Linking a Program with the ICSF Callable Services.

To invoke the callable service, the application program must include a procedure call statement that has the entry point name and parameters for the callable service. The parameters that are associated with a callable service provide the only communication between the application program and ICSF.