If authentication is required at your site, you can configure the WebSphere® MQ-CICS bridge to use the unique user id and an optionally provided password for authentication by a supported external security manager such as RACF®.
You can pass user ids to the CICS® Service Flow Runtime as part of a request message in the WebSphere MQ MQMD structure, field name MQMD-USERIDENTIFIER. See the WebSphere MQ Application Programming Reference for specific information on MQMD-USERIDENTIFIER.
This userid is used in security authentication in the WebSphere MQ-CICS bridge if configured appropriately. Different levels of authentication can be implemented using a user id and an optionally provided password. See Considering security for more information.