Re: SNMPv3 security

>>>>> On Thu, 7 Aug 2003 11:18:34 -0700, "Randy Presuhn" <[email protected]> said:

Randy> ???  Key lifetime is under control of the user / security
Randy> administrator.  If you want to update your keys every ten
Randy> minutes, you can, though it doesn't address the more
Randy> fundamental question of the strength of the crypto algorithm

This has been discussed several times.  Just one more point that I
think Eric is trying to get across but most people are missing: Having
the key lifetime controlled by the manager means that if the box gets
disconnected from the network then the key can't be updated.  This is
important if the box contains critical data.  An attacker that can
sever the network connection (a simple DoS attack would suffice for
this) between the manager and the agent can then spend all the time
the needs to figure out the keys and access the contents of the box.
This is a big difference between other protocols (kerberos, IKE, etc)
that hold a key to a given lifetime at the box itself.  IE, after a
period of time the box itself refuses to reuse the key in question.
Eric's concern in this area is valid, IMHO, but is also nothing new.
Still, I think many people are missing this point.
-- 
Wes Hardaker
Sparta