This is quite interesting, as you are going to use Windows Kerberos service.
FTA "...This article explains, how you can configure the Kerberized Open Secure Shell (OpenSSH) on AIX Version 5.3 machines that have Microsoft Active Directory Server to act as the Key Distribution Center (KDC). OpenSSH encrypts traffic, including passwords, to eliminate eavesdropping, taking over your connection, or peeking into your data. If you work in a hybrid environment with multi-vendor solutions on AIX Version 5.3 systems, then you'll find this article extremely useful.
Open Secure Shell (OpenSSH) is a freely available, open source implementation of the widely used SSH tools, which are used worldwide for communicating securely across networks. It eliminates the possibilities of someone sniffing, taking over, or peeking into your private data by encrypting all communication between two machines. OpenSSH also provides many authentication mechanisms for additional security ..." Read more...
I am sure with little hacks one can implement it using Red Hat Linux too :/?