[ntp:questions] Re: server's address in ntp payload?

David L. Mills mills at udel.edu
Fri Nov 18 21:54:03 UTC 2005


David,

I beg to differ. The session key is a hash of the endpoint addresses, 
key identifier (which changes with every packet) and server private 
seed. The terrorist cannot predict the hash and cannot fake any field or 
guess the server private seed, which changes on a daily basis. Session 
keys are unpredictable, can't be faked and used only once. Replays of 
old keys are detected and discarded. Session keys are cryptographical 
bound to a signed certificate trail and group key.

Dave

David Schwartz wrote:

> "Danny Mayer" <mayer at gis.net> wrote in message 
> news:437D4371.2090004 at gis.net...
> 
> 
>>No it is not a flaw in the protocol design. It would be if it were put
>>in. The address doesn't belong there, it belongs in the IP header which
>>the receiving server always gets.
> 
> 
>     It is a flaw. Its absence requires the receiver to assume that the 
> origin address of the UDP packet received is the IP address of the sending 
> server. This assumption may or may not be correct. But if the address were 
> in there, the assumption would not be needed.
> 
>     DS
> 
> 




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