NODE e8bbc058Re: RemailerNet
jdd@aiki.demon.co.uk (Jim Dixon)Sat, 6 Aug 94 12:02:45 PDT
In message <199408061739.NAA05213@bwh.harvard.edu> Adam Shostack writes:
> | If you are using unmodified Internet hardware and TCP/IP as the underlying
> | transport system, then your point of entry into a remailer network
> | definitely knows which machine is originating a message and the point
> | of exit definitely knows where it is going.
>
> IP is not reliable & trustworthy. It it was, RFC931 ident
> servers would be useful. ;) Theres source routing to make packets
> appear to come from someplace else, and there is outright forgery,
> which has limits, but can work quite well.
My "if you are using unmodified ..." clause shows that I understand this.
You can send from a very large network and forge your TCP/IP or
(more difficult) Ethernet source address. But I can sit on the same
network, build a table relating TCP/IP to ethernet (or whatever)
addresses, and filter out messages that should not be there. There
are commerical packages that do this sort of thing.
Basically, this is a different topic. One problem is designing a
generic software package and set of protocols that will allow you
to route mail anonymously. This is a general problem. The hacking
of specific networks is a different, if related, problem.
--
Jim Dixon
NODE bb184227Re: RemailerNet
"Perry E. Metzger" <perry@imsi.com>Sat, 6 Aug 94 14:07:59 PDT
Jim Dixon says:
> You can send from a very large network and forge your TCP/IP or
> (more difficult) Ethernet source address. But I can sit on the same
> network, build a table relating TCP/IP to ethernet (or whatever)
> addresses, and filter out messages that should not be there. There
> are commerical packages that do this sort of thing.
Huh?
If you are sitting on a network in England, which you appear to be, I
defy you to record anything at all about the ethernet addresses of the
machines that originated this message. I'll happily telnet to your
machine any time you like, and give you all the opportunity you like
to record the ethernet address of my packets. You might be on the same
internet, but you very likely have no access to the original physical
network, and you have no capacity to build any tables of any sort.
Perry