Information theory says that such things are impossible. One can not
construct a spam-free protocol because this is the same problem as
constructing a system free of covert channels, which information theory
says is impossible.
But information theory also says you can optimize signal-to-noise ratio, but
only if you know what the characteristics of your signal are.
Thus my whole motivation for an unambiguous definition (spam == all bulk email)
along the channel and not just a definition at the end points (UBE).
Nobody cares. Making a roof 100.000000% impervious to water molecules
may be impossible, but that doesn't mean we have to resign to getting
wet every time it rains.
People care because when someone comes around saying "you can have a 100%
impervious roof if only you jump through these inconvenient hoops",
Who said 100%?????
Is the problem already reduced to an acceptable S/N ratio for the majority?
Is the current S/N ratio a problem for the majority?
we
know that they are wrong,
How can you know "they are wrong", even you did not even realize that no one
was proposing a 100% solution in this thread??
"We", meaning the IETF, care, because this is very useful aid to deciding
what to work on.
You decline work without even understanding what is being written about a new
idea? No one ever proposed 100% solution. I challenge you to find one post
where I wrote that.
We know that we need to focus on leak stoppage, not
trying to invent leak-proof protocols.
I proposed an way to improve leak stoppage, by defining the signal in the
channel and not only at end points. I never proposed a leak-proof protocol.
Underlying in what you are saying is you don't support new protocols, because
you have a vested interest in existing methods of detection.
We didn't get to the moon by inventing perpetual motion machines,
And many people said it was impossible for us to get to the moon.
though
early proposals were based on such machines. We got to the moon by
working on the messy physics of rockets.
What about the messy information theory of defining the spam signal for the
channel and not just the end points, so that it can be studied and research in
the channel and not only in the receiver's mind????
Have you not realized yet that profound point I am making???
After I first posted this on IETF a while back, someone suggested that
covert channels require cooperation, and that spam therefore isn't a
covert channel.
Where does this covert channel stuff come from anyway?
What do you mean?
The use of covert here probably meant that making anything 100% covert is
impossible in information theory.
But this is a simpler way to think about it: Spammers can continue to
claim they are legitimate emailers, because they _ARE_ legitimate, so
far as we know before they send email. And even so far as we know
_before_ someone _READS_ their email. Only after reading their email,
and perhaps only after some investigation, can we know for sure that
the sender and message is conducting abuse or in violation of their
AUP.
You exactly stated the problem. We have not defined spam (the signal we need
to sample) in terms of the channel. If you define it as ALL BULK EMAIL, then
you can actually start some messy science of getting to the moon on spam
issue...
This goes for each individual message, but the spammer's achilles heel
is that they need to send out incredible amounts of email in order to
fulfill their objectives, whichever those are. Detecting bulk mail is
doable, and it shouldn't be too hard to come up with something to
differentiate legitimate bulk emailing from spam. For instance, we can
reverse the burden of proof here and only allow know bulk emailers.
"Detecting abuse" is quite different from making a protocol that can't be
abused. But that is my point: You have to focus on detection. This
doesn't require any protocol changes whatsover.
You can not measure a signal if you have not defined it. That is a fundamental
concept of information theory. Spam is ambigous in the channel, unless you
define spam == all bulk email. How many dozens of times have I written that in
this thread!
We are already "only allowing known bulk emailers". Unfortunately, that
doesn't prevent spam.
SOBO (statement of blatantly obvious) that you can't filter something if you
can't define it. That information theory 101.
Indeed, it seems most of the spam isn't commercial:
Most of the spam seems to come from viruses, and isn't really selling
anything. The viruses can use the credentials of the infected user.
That is "legitimate", until someone reading the email realizes its not and
complains. These send 40-50 messages per IP, and is hard to detect as
bulk.
Viruses are a different signal and can be filtered as such, unless they contain
no viral data.
No, that's the point. It isn't _fixable_ with authentication. It isn't
fixable at all. It is only "fixed" when the spammer loses his account.
Then the spammer gets a new account. So it isn't really fixed. So we are
always going to be playing a game of whack-a-mole. That cannot be avoided
by altering the protocol or the authentication scheme (information theory
proves this). So it is useful, then, to work on ways of detection,
Agreed. And you can not detect well if you can not define what you are
detecting.
improve our whack-a-mole skills. Altering protocols and authentication is
a waste of time.
Er... unless they improve our ability to detect.
Shelby Moore
http://AntiViotic.com