With encryption on a host-by-host basis, each host must support cryptography, and cryptographic key data sets must be filed at each host involved in the LU-LU session initiation.

In Figure 1, for cryptographic sessions to exist between resources in VTAM1 and VTAM3, cryptographic key data sets must be filed at VTAM1, VTAM2, and VTAM3.

Figure 1. Encryption facility in multiple-network environment