Re: Blocking addresses by default

-----BEGIN PGP SIGNED MESSAGE-----

Mark M. wrote:
> 
> -----BEGIN PGP SIGNED MESSAGE-----
> 
> With remailer abuse becoming more popular and remailers going down
> because of complaints, there seems to be some interest in remailer
> software that will block all email by default and will only pass
> along email that is explicitly unblocked.

I think this threatens serious security problems for the remailer 
network in two ways:

1. You'd create a list of people interested in anonymous information,
   which could potentially be obtained by police or other armed thugs.

2. The traffic would go down so substantially that traffic analysis     
   would be trivial.

As a counterproposal, I'd like to see better disclaimers on remailed 
messages. The reason the people complaining are so pissed off is that 
the blocklists are neither advertised nor automated enough. I'd like to 
see disclaimers and block list instructions at the top of the body of 
every single message. This would be encapsulated in some mark characters 
so that it could easily be removed by remailer chains. E.g.,

 To: remailer@erehwon.com

 Request-Remailing-To: remailer@nowhere.com

 [message]

remailer@erehwon.com prepends the following to the message before it is 
sent along:

 $$
 This message was sent through the anonymous remailer network. Neither
 the operator of this remailer, remailer-op@erewhon.com, nor the
 postmaster at this site has any way of determining the source or
 filtering the content of remailer messages. No logs are kept. If you
 do not wish to receive such anonymous messages from any link in the
 remailer network, send an email message to remailer-operators@c2.net
 with subject line "block." For more information on the remailer
 network, see [Raph's list] or send email to help@[?].
 $$

remailer@nowhere.com looks for "$$" as the first line of the message, 
and strips everything up to the next occurrence of "$$". It then appends 
its own disclaimer block before sending the message to the hop (remailer 
or final destination).

A bit annoying, yes, but I think this would go a long way towards 
improving public relations. I don't see how it compromises security.

What's wrong with this scheme? Other than the fact that all remailers 
would have to change their software at the exact same moment. :-)

[By the way, someone told me that the Chardos remailer doesn't include 
Complain-To or block-list instructions anywhere, not even in X-Headers.
Is this true? I think that would be bad. [tm]]

- -rich
- ---
[This message has been signed by an auto-signing service.  A valid signature
means only that it has been received at the address corresponding to the
signature and forwarded.]

-----BEGIN PGP SIGNATURE-----
Version: 2.6.2
Comment: Gratis auto-signing service

iQBFAwUBMoJFnCoZzwIn1bdtAQEZSwF/eurxI6jVBcv4srS8FEE3Rtc5rVCTfyw8
gNrC5p5ZzBGgFCaM3MOair4gH91zH/HK
=oqSh
-----END PGP SIGNATURE-----

-----BEGIN PGP SIGNED MESSAGE-----

On Thu, 7 Nov 1996, Rich Graves wrote:

> I think this threatens serious security problems for the remailer
> network in two ways:
> 
> 1. You'd create a list of people interested in anonymous information,
>    which could potentially be obtained by police or other armed thugs.

True.  I wasn't proposing any centralized list or a complete alternative to
the current way remailers are set up.  Just an alternative for some people who
don't have time to go through all the complaints.  The only unblocked addresses
could just be the addresses of other remailers.  Others could be set up to
only deliver mail to other remailers, mailing lists, and newsgroups.

> 
> 2. The traffic would go down so substantially that traffic analysis
>    would be trivial.

If every remailer adopted this system, then this would be true.

> As a counterproposal, I'd like to see better disclaimers on remailed
> messages. The reason the people complaining are so pissed off is that
> the blocklists are neither advertised nor automated enough. I'd like to
> see disclaimers and block list instructions at the top of the body of
> every single message. This would be encapsulated in some mark characters
> so that it could easily be removed by remailer chains. E.g.,

This is a good idea.  I also like the idea of remailers forwarding some sort
of notification to a first-time recipient where the recipient actually has to
request that the mail be delivered.  However, the storage requirement might be
a little impractical for some remailers.  If the disclaimers are really
annoying, it would be easy enough to remove these disclaimers with a simple
procmail recipe or some equivalent.


> What's wrong with this scheme? Other than the fact that all remailers
> would have to change their software at the exact same moment. :-)

The "cutmarks" option would allow backwards compatability.  Alternatively, the
remailer might be able to determine whether the next hop is a "real" email
address or another remailer.  I believe this would be pretty easy with
Mixmaster since a remailer can tell if it is the final hop or not.


Mark






-----BEGIN PGP SIGNATURE-----
Version: 2.6.3
Charset: noconv

iQEVAwUBMoPTpizIPc7jvyFpAQGYHggAqERGxbUu4LcGmP6qgN47claY9cttmWQ+
LIxHFKKxut92mSVMfDD80WGlXZAQb/p97t//m6aGZ3cCFXe8JPlVfyqrzz4A4/JK
pN3lbn0Vfk08CVePFZaBqk8yiE+K7ZpjE1vTx8GTna0n+ZHpC6RZ1DBNwWrif4PH
kLUl4cFHYeHhe9qfZrc+rjUcxe0yMM9hhJ3uW1SUaUvLeXNuwjaftil5ULX1pegt
2JLYZkX7UF7EAUA2GvKj1KoDhVoQjT5tbRcIbV20n8r8mQjQuecUqZXP/P9D1zbC
lwilKC5z2+0wErr9MvseLH9CEriVQhT0EN1fWxZjB3MfrCFRdNDO9w==
=xP+H
-----END PGP SIGNATURE-----

On Thu, 7 Nov 1996 15:25:07 -0500, Rich Graves wrote:

   remailer@nowhere.com looks for "$$" as the first line of the message, 
   and strips everything up to the next occurrence of "$$". It then appends 
   its own disclaimer block before sending the message to the hop (remailer 
   or final destination).

   A bit annoying, yes, but I think this would go a long way towards 
   improving public relations. I don't see how it compromises security.

Neither do I.  I think it should use something like a line of dashes,
or maybe a C comment, though, rather than $$, to make it look
'prettier' for the eventual recipient, and clarify that it's not part
of the original message.

   What's wrong with this scheme? Other than the fact that all remailers 
   would have to change their software at the exact same moment. :-)

This is not true, of course.  Implement it in two stages.  First
recognise and strip the disclaimer, but don't prepend one, then, when
all remailers are doing this, start prepending information.

-- 
Paul Foley <mycroft@actrix.gen.nz>       ---         PGPmail preferred

	   PGP key ID 0x1CA3386D available from keyservers
    fingerprint = 4A 76 83 D8 99 BC ED 33  C5 02 81 C9 BF 7A 91 E8
----------------------------------------------------------------------
I must have slipped a disk -- my pack hurts