In most cases, all you'll notice is that you no longer have to type your password, because Kerberos has already proven your identity. Be aware that, depending on how the program is configured and whether the target machine is Kerberized, you may be prompted for either userid or password, both, or neither. For ssh configuration, see the ssh man pages. See the man pages for complete information. Here we list only the command syntax and the Kerberos-added features for these programs.
Encryption also ensures data integrity.
The discussion here is adapted from the ksu man pages. See them for more information, in particular for option descriptions. Resolving the target principal name is the first step in authentication. If the source user is root or the target user is the source user, no authentication or authorization takes place. In all other cases, ksu looks for an appropriate Kerberos ticket in the source cache.