Selective data encryption

The application program specifies whether data is encrypted by using the keyword CRYPT=YES or CRYPT=NO on the APPCCMD macroinstruction. YES means to encrypt the data before it is sent. This keyword applies to the following macroinstructions:

APPCCMD CONTROL=DEALLOC, QUALIFY=DATACON (HDX only)
APPCCMD CONTROL=DEALLOC, QUALIFY=DATAFLU
APPCCMD CONTROL=PREPRCV, QUALIFY=DATACON (HDX only)
APPCCMD CONTROL=PREPRCV, QUALIFY=DATAFLU (HDX only)
APPCCMD CONTROL=SEND, QUALIFY=DATA
APPCCMD CONTROL=SEND, QUALIFY=DATACON (HDX only)
APPCCMD CONTROL=SEND, QUALIFY=DATAFLU

If a session is not using selective or required cryptography and CRYPT=YES is specified in any of the preceding macroinstructions, VTAM® issues the return code RCPRI=002C, RCSEC=0028, which means that cryptography is not allowed.

Note: If any of the data in the SEND buffer is to be sent encrypted (as indicated by the application program on the SEND, PREPRCV, or DEALLOC macroinstruction), all data in the RU is encrypted. (The buffer size is determined by the user's maximum RU setting.)