CWAKEY

The CWAKEY system initialization parameter specifies the storage key for the common work area (CWA) if you are operating CICS with storage protection (STGPROT=YES).

CWAKEY={USER|CICS}
You specify how much storage you want for the CWA on the WRKAREA parameter. The permitted values are USER (the default), or CICS:
USER
CICS obtains storage for the CWA in user key. This allows a user program executing in any key to modify the CWA.
CICS
CICS obtains storage for the CWA in CICS key. This means that only programs executing in CICS key can modify the CWA, and user-key programs have read-only access.

If CICS is running without storage protection, the CWAKEY parameter is ignored, and the CWA is always allocated from CICS-key storage.