spamassassin-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From John Hardin <jhar...@impsec.org>
Subject Re: Discussion side point: levels of Trust
Date Mon, 16 Jun 2008 18:20:23 GMT
On Mon, 16 Jun 2008, Linda Walsh wrote:

> John Hardin wrote:
>>  On Wed, 11 Jun 2008, SM wrote:
>> 
>> >  At 17:46 11-06-2008, Linda Walsh wrote:
>> > >       How does one decided on 'trust'?  I.e. I think it would be
>> > >  useful to assign a probability to "Trust" at the least.  I mean do I 
>> > >  put
>> > >  my ISP in my trusted server list?   -- suppose they start partnering 
>> > >  with
>> > 
>> >  It could be a reputation system where you assign a probability.
>>
>>  Probability of what, exactly?
>>
>>  Bear in mind, "trusted" means "does not forge Received: headers", not
>>  "does not send or relay spam".
>
> I am aware of this.
> However, it's not an easily discerned number, but if I had att or 
> comcast as an ISP, my trust in them would maybe be a trust value .7-.8.

You think they shouldn't be trusted to honestly report the IP address 
their MTA accepts a message from?

> Like the ISP in Europe who insertted over 20million ads on HTML pages -- 
> they could just as easily be adjusting return headers.

The situations aren't parallel. The HTML modification had a profit motive 
(at least until they lose enough in litigation to offset the profits from 
inserting ads in other people's web pages). Where is the motivation to 
forge Received: headers or lie? About the only scenario I can think of is 
that they are an ISP who knowingly hosts spammers.

Where would an investigative need to report incorrect Received: data 
arise? Obscuring the source of an FBI keylogger-insertion email? Perhaps. 
How is that relevant to spam detection?

If you are a subscriber of a given ISP and you're retrieving your mail 
from a mailbox at that ISP via POP/IMAP, you pretty much can't avoid 
trusting them. They are the public-facing interface of your account. How 
would fractional trust work in such a scenario?

-- 
  John Hardin KA7OHZ                    http://www.impsec.org/~jhardin/
  jhardin@impsec.org    FALaholic #11174     pgpk -a jhardin@impsec.org
  key: 0xB8732E79 -- 2D8C 34F4 6411 F507 136C  AF76 D822 E6E6 B873 2E79
-----------------------------------------------------------------------
   The world has enough Mouse Clicking System Engineers.
                                                        -- Dave Pooser
-----------------------------------------------------------------------
  2 days until SWMBO's Birthday

Mime
View raw message