Session level cryptography

Session level cryptography encrypts and decrypts session data using the DES algorithm. It can therefore be used to provide a link level confidentiality service on SNA LU 6.2 channels.

Logical units (LUs) can provide mandatory (or required) data cryptography, selective data cryptography, or no data cryptography.

On a mandatory cryptographic session, an LU encrypts all outbound data request units and decrypts all inbound data request units.

On a selective cryptographic session, an LU encrypts only the data request units specified by the sending transaction program (TP). The sending LU signals that the data is encrypted by setting an indicator in the request header. By checking this indicator, the receiving LU can tell which request units to decrypt before passing them on to the receiving TP.

In an SNA network, IBM MQ MCAs are transaction programs. MCAs do not request encryption for any data that they send. Selective data cryptography is not an option therefore; only mandatory data cryptography or no data cryptography is possible on a session.

For information about how to implement mandatory data cryptography, see the documentation for the SNA subsystem. Refer to the same documentation for information about stronger forms of encryption that might be available for use on the platform, such as Triple DES 24-byte encryption on z/OS .

For more general information about session level cryptography, see Systems Network Architecture LU 6.2 Reference: Peer Protocols, SC31-6808.