Re: Novel use of Usenet and remailers to mailbomb from luzskru@cpcnet.com

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Bear with me - original text follows all these quotes

At 2:29 PM1/13/96, bryce wrote:
>> If "digital postage" is ever implemented, this sort of
>> distributed-origin mailbomb-through-a-remailer would be stopped
>> immediately.  All the messages that the horny net geeks send would
>> necessarily contain the same postage stamp, and the remailer would
>> notice this right away -- and throw away messages containing the used
>> postage stamp.
>>
>> One more motivation for e$-like digital postage for remailers.
>
>
>Unfortunately this is not the case.  The perpetrator would
>simply have to convince the horny net geeks to pay their own
>postage.  In fact, it is *in general* impossible to have both
>anonymity and prevention/control of mail-bombing.  Of course
>digital postage will help the problem somewhat by making the
>bombers pay for it, and smarter filters on the recipient's end
>will help, but in general it is a problem we are going to have
>to live with if we want anonymity.

Impossible is an awfully strong word.

If I was going to implement free digital stamps, I'd have a autoreply
daemon (stamps@remailer.com) that when sent a mail, would respond with X
number of valid stamps.  If you're going to trust me not to log my remailer
traffic, extending that trust to believing I won't log the stamp requests
shouldn't be that much of a stretch.

Alternatively, the stamp could consist of a unique-id, any unique-id,
working identically to Usenet message ids.  That way, the user can generate
his own stamps without being forced to trust the remailer operator not to
log them.

I prefer the second option as it has both greater anonymity and allows for
simple history file patching to the remailer.

Either way, if the stamps/message-ids are forced to be inside the encrypted
address block, mail-bombers can only get one message through.  Even if the
HNGs are instructed to add a stamp and re-encrypt the address block, when
the spam-o-grams start getting routed through the pre-packaged route,
they'll be stopped dead after one message gets through.

Joseph Block <jpb@miamisci.org>

"We can't be so fixated on our desire
 to preserve the rights of ordinary Americans ..."
 -- Bill Clinton  (USA TODAY, 11 March 1993, page 2A)
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 I wrote:
>
> In fact, it is *in general* impossible to have both
> anonymity and prevention/control of mail-bombing.  Of course
> digital postage will help the problem somewhat by making the
> bombers pay for it, and smarter filters on the recipient's end
> will help, but in general it is a problem we are going to have
> to live with if we want anonymity.
 
 
 An entity calling itself Joe Block allegedly wrote:
>
> Impossible is an awfully strong word.
 
 
Indeed.  And I would be delighted (sort of) if someone could
show me how my assertion above is incorrect.
 
 
> If I was going to implement free digital stamps, I'd have a autoreply
> daemon (stamps@remailer.com) that when sent a mail, would respond with X
> number of valid stamps.
 
 
<snip>


Look I don't actually understand how remailers are currently
implemented, but for the purpose of this discussion it doesn't
matter.  Any sequence of steps that a legitimate correspondant
can use to send a letter a mailbomber can use to send an 
e-mailbomb.


Now you can make the sequence of steps more complex in the 
hope of weeding out the less technically competent mailbombers,
but this is a weak solution which will also make remailnet even
more inaccessible to the barely technically competent people
who make up the vast majority of e-mail users.


Look at it this way.  How can one ensure that one receives only
the kind of e-mail that one likes?  I can think of only 3 ways:


1.  Discriminate based on content.  (killfiles, etc.)
2.  Discriminate based on authorship.  (PGP sigs, reputations,
etc.)
3.  Retaliate against those who send you mail that you didn't
want.  (mail-bombing, reputation-trashing, social or legal
penalties, violence, assassination, etc.)



Now unconditional anonymity (or even "Pretty Good" anonymity a
la cpunks remailers) does away with option #3, right?  (I take 
a moment to note that this is precisely *why* we advocate
anonymity in the first place...)


So that leaves us with option #1 and option #2.  It is
impossible for current computers to reliably identify for us
whether a given e-mail message is junk mail or not.  (I take a
moment to note that when it becomes possible for computers to do
so we will probably have bigger things to worry about...)
  *But* there is a lot that done with regard to discrimination
based on content.  First there's the obvious stuff-- killfiling
topics and keywords (like "NSA" and "ITAR" on cpunks...) and
splitting messages into different folders based on which list
they are from-- and then what about this idea:  someday people 
will include a few micro-dollars in their messages to encourage 
you to read them.  Now that would be interesing.


Now the schemes that I have seen aired here about how to
prevent these kinds of distributed e-mailbombs generally
focussed on a rough version of option #1-- just discriminate
against multiple copies of the same content.  That's fine
(although some of my friends who are always sending me the same
jokes might get left out in the cold...) but you have to realize
that it is a weak fix that can be easily overcome by a
technically sophisticated attacker.


Also I think all such things should be done on the user's end.
I would thank *my* anonymous remailers to let me and my computer
decide what mail to trash.


Of course as always people should pay as they go to send mail.
Thus no direct financial harm is done to the recipient (or even
a pecuniary bonus!  See above) and the remailers could probably 
make a profit off of mailbombers.


I'll leave option #2 alone.  No fresh ideas today.


Okay I've wandered, but to restate my main point mailbombing 
and anonymity are *in general* inseparable.  Just as harassment,
intimidation, blackmail, libel, copyright violations and other 
"information crimes" will be encouraged by anonymity.  Get used
to it, or else stop advocating anonymity.


Regards,

Bryce

PGP sig and clear-text timestamp follow


Mon Jan 15 15:46:21 MST 1996

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if you get the usual 150+ msg/day I do, you break it up into
    folders, set the reader to proceed sequentially through the folders,
    in an order defined in .pinerc. I have 30 folders current.

	when a particular person becomes annoying:

	    # net assholes 

	    :0 HB 
	    * ( Fred.*Cohen|fc@all.net|vznuri|kevin.dirks )
	    assholes

    takes care of the problem nicely.  

	If you get bored with a newsletter, etc. I move its 
    folder address in procmail to "bigsleep" and every so 
    often I try to cancel the group.

	Now, if I wish to really get hostile, I have a little 
    program which returns the message showing "bounce@..." in 
    the From:, Reply-To:, and Sent-By: fields. At the top of the 
    body it 'shouts' the sender is objectionable and the mail
    returned.  It does keep a log of who it bounced and if it
    one of the no-return types, it 'learns' from another list 
    to use /dev/null.  

	There is no limit to how far you can go, including mail 
    bombing. spoofing the top line From is hard to do for lack 
    of insecure mailers, but it can be done by other means. The
    only spammer I have had trouble discouraging is nashville.net.
    But I really do not believe in mail bombing as it hurts too
    many bystanders --cheap to generate, but expensive to clean
    up after.

	So, indulge in procmail(), premail(), formail(), and 
    older versions of smail() and join the fun.

__________________________________________________________________________
    go not unto usenet for advice, for the inhabitants thereof will say:
      yes, and no, and maybe, and I don't know, and fuck-off.
_________________________________________________________________ attila__

    To be a ruler of men, you need at least 12 inches....