RE: question on key localizaton

HI,

Your guess below at how things work and how keys are managed is incorrect.
At 11:15 AM 11/16/2002 +0900, ??? wrote:
>Let me rephrase what you mean.
>
>Suppose that there are a single manager engine M and N agents engines A1, A2, A3, ... An.
>If there is no INFORM from an agent to the manager, then
>all the agent's diffent keys are known to the manager but any agent couldn't figure out 
>another agent's key and hence no agent can corrupt other agnets.
>However, If INFORM from any agent to the manager is allowed, then 
>A1 should know a secName1 on the manager and corresponding key K1. ( athentication key or privacy key, whatever )
>because the manager is the authoritative side in this case.
>A2 should know a secName2 on the manager and corresponding key K2.
>A3 should know a secName3 on the manager and corresponding key K3.
>...
>An should know a secName-n on the manager and corresponding key Kn.
>
>But, keeping unique secNames per agents is an administrative nightmare.
>So it is 99 % probable that secName1 = secName2 = secName3 = ... secName-n and K1 = K2 = K3 = ... Kn.
>At last, we have one common user and one common key all around the management domain.
>This user and key can be used maliciously.
>
>Is this what you mean?
>
>If right, we had better forbid INFORM from agents to the manager or 
>take over the administrative nightmare.
>
>
>-----Original Message-----
>From: Wes Hardaker [mailto:[email protected]]
>Sent: Saturday, November 16, 2002 4:03 AM
>To: Uri Blumenthal
>Cc: 3aCoAI; [email protected]
>Subject: Re: question on key localizaton
>
>
>>>>>> On Fri, 15 Nov 2002 13:57:04 -0500, Uri Blumenthal <[email protected]> said:
>
>Uri> "The same key" is NOT the same as "the same LOCALIZED key". So
>Uri> yes, all those keys would be DERIVED from the user key owned by
>Uri> secName, and all those keys will be different and
>Uri> cryptographically "unrelated" due to localization process.
>
>Uri> Am I missing something here?
>
>Yes you are.  The engineid for the localization process in a SNMPv3
>inform is the notification receiver.  That means that the same key
>(which is a localized key, but is always the same) is used across all
>systems on a network (unless a unique secName is picked for each
>system, which is certainly one way around the security problem, albeit
>an administrative nightmare).
>
>Uri> One of us is missing something. The question is - who and what? (:-)
>
>It's you ;->
>
>-- 
>Wes Hardaker
>Network Associates Laboratories