ICSF supports VTAM session-level encryption. VTAM session-level encryption provides protection for messages within SNA sessions, that is, between pairs of logical units that support their respective end users. When this method of protection is in effect, data is enciphered by the originating logical unit and deciphered only by the destination logical unit. Thus, the data never appears in the clear while passing through the network.

ICSF places no restrictions on the addressing mode of calling programs. In particular, when VTAM session-level encryption is used with ICSF, VTAM can use storage greater than 16 megabytes.