Authentication Methods in SQL*NET (V2)

What sort of authentication options are there using SQL*NET? (SQL*NET version 1 didn't seem to have too many, so I guess I am more interested in SQL*NET version 2).  

My concern comes from an environment where the ethernet carrying the TCP/IP traffic is likely to have a sniffer on it, so passing the ID and password in the clear (as V1 appears to do), is not a good thing.

Is there any way to have it use Kerberos for authentication? Or a smart card or other one time key authentication?

Can the data transfer be encrypted?

Any information would be appreciated.

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Jon Finke                           finkej_at_rpi.edu
Senior Network Systems Engineer     http://www.rpi.edu/~finkej
Information Technology Services     518 276 8185 (voice) | 518 276 2809 (fax)
Rensselaer Polytechnic Institute    110 8th Street, Troy NY, 12180