Re: An overview of cryptographic protocols to prevent spam

2005-09-26 Thread Amir Herzberg

John Gilmore wrote:
I wrote an overview of Cryptographic Protocols to Prevent Spam, 


I stopped reading on page V -- it was too painfully obvious that Amir
has bought into the whole censorship-list based anti-spam mentality.
John, I'm disappointed; I expected you to be more tolerant. You got mad 
at me at page V which is still just reviewing the basic e-mail 
architecture related to spam. In this part, I explained what open-relays 
are and why people may try to disconnect from them, and described 
port-25 blocking which is common practice and necessary to protect 
domains from being blacklisted.


I discuss blacklisting techniques and their problems much later, in 
section 5.5 (page XXV). I discuss there, albeit briefly, false 
positives, abuse, and collateral damage. I agree about the importance of 
clarifying these concerns, and will try to improve this.


Frankly, however, I think you were a bit trigger-happy to conclude that 
I `bought-into` the censorship, black list approach. May I recommend 
that you ask first, shoot later? We had some discussions on this and 
while we may have differences, I thought you know I care a lot about 
freedom of speech.


And btw, yes, as users of some (legitimate!) mail services, both me and 
several family memebers (e.g. children) were blocked by domain 
blacklists... When this happened to my 7 year old child, I had to 
forward his answers to a magazine for him. I once almost lost a 
consulting engagement to blocked email. And Ross Anderson once had to 
resort to asking Adi to call me on the phone to deliver a message, since 
a crazy mail filter here (Bar Ilan Univ.) blocked his messages for 
weeks... And more incidents. So believe me I'm well aware of this problem.

--
Best regards,

Amir Herzberg

Associate Professor
Department of Computer Science
Bar Ilan University
http://AmirHerzberg.com
Try TrustBar - improved browser security UI: 
http://AmirHerzberg.com/TrustBar
Visit my Hall Of Shame of Unprotected Login pages: 
http://AmirHerzberg.com/shame


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Re: An overview of cryptographic protocols to prevent spam

2005-09-26 Thread John Gilmore
 I wrote an overview of Cryptographic Protocols to Prevent Spam, 

I stopped reading on page V -- it was too painfully obvious that Amir
has bought into the whole censorship-list based anti-spam mentality.

It was hard to get from paragraph to paragraph without finding
approving mentions of blacklists.  I am a victim of many such
blacklists.  May Amir never appear on one, or his unthinking
acceptance of blacklisting might change.  His analysis made me think
of clinical reviews of experiments done on human subjects in prison
camps -- careful to focus on the facts while ignoring the obvious
moral problems.

Interspersed were discussions of various kinds of port blocking.  The
Internet is too good for people who'd censor other peoples'
communications, whether by port number (application) or by IP address
(person).  It saddens me to see many of my friends among that lot.

John Gilmore



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Re: An overview of cryptographic protocols to prevent spam

2005-09-26 Thread Adam Shostack
On Mon, Sep 26, 2005 at 09:28:19AM +0200, Amir Herzberg wrote:
| John Gilmore wrote:
| I wrote an overview of Cryptographic Protocols to Prevent Spam, 
| 
| I stopped reading on page V -- it was too painfully obvious that Amir
| has bought into the whole censorship-list based anti-spam mentality.
| John, I'm disappointed; I expected you to be more tolerant. You got mad 
| at me at page V which is still just reviewing the basic e-mail 
| architecture related to spam. In this part, I explained what open-relays 
| are and why people may try to disconnect from them, and described 
| port-25 blocking which is common practice and necessary to protect 
| domains from being blacklisted.

necessary to protect domains from being blacklisted.?

How about the more factual:   Is used as a decision factor by many of
the programmers who create blacklist-creation tools?

Blacklists are not like blackholes, a natural result of laws of
nature.  They are the product of human action, and the people who made
decisions around them ought to own up to the fact that they are making
decisions.

Adam

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Re: An overview of cryptographic protocols to prevent spam

2005-09-26 Thread Perry E. Metzger

John Gilmore [EMAIL PROTECTED] writes:
 It was hard to get from paragraph to paragraph without finding
 approving mentions of blacklists.  I am a victim of many such
 blacklists.  May Amir never appear on one, or his unthinking
 acceptance of blacklisting might change.

I'm afraid that I use blacklists. My servers get about 30,000 spams
and virii directed at me (that is me, Perry Metzger, personally) every
night that are blocked by blacklists. I would be unable to write you
this email if I didn't use blacklists, because I'd have no working
email at all. (To be fair, the onslaught has diminished recently --
I'm now down to perhaps 20k a night. There is no functional
difference.)

I've also been blacklisted myself, and I've had to deal with
it.

I understand your position, but you should understand that for many of
us spam, virus spew, etc. is not merely an annoyance but has the
ability to literally make it impossible to use email. Using a
combination of blacklists and other mechanisms, I get the spam levels
down to the point where they are merely an annoyance, but without them
I'd be incapable of receiving email any longer.

An analogy I like to use here is that while your neighbor using a
flashlight in the night might be an annoyance, and turning on
floodlights in the night might be a substantial annoyance, bathing
your house in hundreds of megawatts of light day and night goes beyond
mere annoyance and eliminates your ability to enjoy the use of your
property.

A few unwanted emails are a mere annoyance, but at the levels I've
reached, they go beyond annoyance. As much as I dislike blacklists
etc., I couldn't operate without them so I use them.

I wish I lived in a world where you couldn't just go out and lease the
use of 8000 zombie machines on the internet pre-broken into by
Ukrainian gangsters for your spamming pleasure, where people couldn't
send me phishing emails without being caught and punished for fraud,
etc. -- in short where folks who do things that even libertarians
dislike were punished. However, we don't live in an ideal world -- we
live in a world where a government monopoly runs law enforcement and
that law enforcement is nigh well worthless. I can't just buy the
other government's law enforcement since there is none, so I do what I
can on my own to make my machines livable.

In a better world maybe we won't need firewalls, policies where cable
modem users have port 25 blocked unless they ask for it to be
unblocked, spam blacklists, vast amounts of personnel time and money
spent at large organizations worrying about spam, security, etc., but
that better world isn't coming any time soon.

 His analysis made me think of clinical reviews of experiments done
 on human subjects in prison camps -- careful to focus on the facts
 while ignoring the obvious moral problems.

 Interspersed were discussions of various kinds of port blocking.  The
 Internet is too good for people who'd censor other peoples'
 communications, whether by port number (application) or by IP address
 (person).  It saddens me to see many of my friends among that lot.

John, I admire you for living a life without compromises. However, I
cannot afford such a life.

As it stands, I wouldn't blame the people who block ports. Most of
them, like me, are just trying to keep using the internet as best as
they can.

I would blame the criminals. I don't mean the people who merely send
out unsolicited email from machines they themselves own that doesn't
pretend to come from other people. I mean the people who
systematically break in to thousands of computers (surely you don't
believe breaking in to someone's computer to gain its use against the
will of the owner is okay) so they can send out their notes to a few
million people claiming to be their bank and directing them to yet
another machine they've broken in to where they collect the passwords
of the victims. I would also blame the law enforcement agencies who
essentially do nothing to these people.

Perry

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Re: An overview of cryptographic protocols to prevent spam

2005-09-26 Thread Perry E. Metzger

One more comment note on spam...

Perry E. Metzger [EMAIL PROTECTED] writes:
 I'm afraid that I use blacklists. My servers get about 30,000 spams
 and virii directed at me (that is me, Perry Metzger, personally) every
 night that are blocked by blacklists. I would be unable to write you
 this email if I didn't use blacklists, because I'd have no working
 email at all. (To be fair, the onslaught has diminished recently --
 I'm now down to perhaps 20k a night. There is no functional
 difference.)

My mother in law recently got rid of the email address she had been
using for many years. Why? She was getting so much spam that the
address was effectively useless. To find the one real message she had
to wade through a metric ton of porn, medical fraud, bank fraud and
ads for fake rolexes. Her anti-spam facilities in her mail reader were
pretty good but kept putting real messages into the spam folder, so
after a while it became obvious that they weren't helping since she
had to parse all the spam by hand anyway. In short, she was forced to
surrender. She abandoned the account.

She's not the only person I know who's done things like this. Spam is
not a harmless annoyance any more than insect bites are once you
start getting enough. It threatens the ability to actually use email
for communication.

In a normal society, by now people would have email directories online
where you could look up the email addresses of friends and loved
ones. Why don't we have those? Spammers. People actually go through a
whole lot of trouble NOT to have their email online. They do things
like turning their email addresses into images on their web sites so
automated harvesters can't read them. They post from throwaway
accounts assuring that no one who wants to reply will ever be able to
do so. They bend over backwards trying to avoid the spammers.

ISPs have to spend vast amounts of money one extra bandwidth to carry
this garbage -- it costs real money. Companies have large staffs of
people who work full time to ameliorate (not eliminate) their spam
problems. It costs them real money. People like my mother in law
abandon email addresses (and make it impossible for old friends to
find them) because they're scared that if too many people know their
email address it will become flooded with garbage. By the way, the
criminals now do stuff like using spyware to steal people's addresses
so it is literally the case that you have to worry that too many
people know your address.

This is not a normal situation any longer. Spam has distorted people's
behavior beyond all recognition. You can pretend that hasn't happened
and that really all that is needed is heavier use of the d key or
perhaps slightly better Bayesian filters, but in fact that's not the
situation any more. We're beyond that. You can argue that we're
wrecking the internet to save it, but what is, realistically, the
alternative? If you say just ignore the spam then I'll have to
politely ignore *you* -- I cannot try to find the 50 real messages
inside of the 30,000 garbage ones addressed to me without the evil
blacklists, and you wouldn't be able to either.

We either make the internet somewhat less of what it was so that we
can continue using it at all, or we keep it pure and cease to use it
altogether. Given the choice, I'll compromise on purity.

Perry

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