Re: PGP posting validation

Robert A. Hayden [hayden@krypton.mankato.msus.edu] wrote:

> > Here's my two cents' worth- how about a filter on incoming mail to the list
> > that performs these functions:
> >   1) check the incoming post for a PGP signature
> >   2) If a sig is found, check it against the list's public keyring

	Hmm.. this would allow us to prove that THE LIST thinks he's
who he says he is.. or who THE LIST tells us he is.. Now, I am not
paranoid against THE LIST, but I suggest that THE PEOPLE should
not filter THEIR thoughts.  What of censorship [on an aside, is there
a censor apprenticeship?  Why the 'ship?']!?  If you must censor.. 
censor your own messages with filters running on your own machine..
maybe even publish your filter list to the net so we can all understand
each other.  Remember that there will always be a percentage of noise
in any public forum.. there is no average without these outliers.  
For a group SO interested in RANDOM numbers, some people sure do want
to organize everything.  TTFN.

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

On Sun, 16 Jan 1994, DrZaphod wrote:

>   Robert A. Hayden [hayden@krypton.mankato.msus.edu] wrote:

Just to verify, I followed up to a previous posting, it wasn't mine 
originally :-)

> 
> > > Here's my two cents' worth- how about a filter on incoming mail to the list
> > > that performs these functions:
> > >   1) check the incoming post for a PGP signature
> > >   2) If a sig is found, check it against the list's public keyring
> 
> 	Hmm.. this would allow us to prove that THE LIST thinks he's
> who he says he is.. or who THE LIST tells us he is.. Now, I am not
> paranoid against THE LIST, but I suggest that THE PEOPLE should
> not filter THEIR thoughts.  What of censorship [on an aside, is there
> a censor apprenticeship?  Why the 'ship?']!?  If you must censor.. 
> censor your own messages with filters running on your own machine..
> maybe even publish your filter list to the net so we can all understand
> each other.  Remember that there will always be a percentage of noise
> in any public forum.. there is no average without these outliers.  
> For a group SO interested in RANDOM numbers, some people sure do want
> to organize everything.  TTFN.

Please don't take this as confrontational (ie, this is not a flame :-)

How would requiring that postings made to a list be verifyable be 
censorship?  What it does is verify that REAL people posted the message 
and that the person who's address is on the message is actually the person 
that posted it.

Now, granted, I suppose it could end up dumping some postings because 
they were forged, and that is sort of censoring.  But it isn't censoring 
based on content, but based on the fact that it appears to be a forgery.  
And by bouncing a message back to the person that posted it, you give 
them an opportunity to repost (this time signed) in case they forgot.

Also, as for the filter idea.  If some jerk is posting a message as 
appearing to come from schmuck@foo.bar.com, yes, I could add that address 
to my filter and delete it before i see it, but if the jerk starts 
posting as coming from idjit@bar.foo.com, I'd have to add another filter 
line.

By doing a check of the digital signature against the posters public key, 
you eliminate most instances of forgery.  Of course, if the poster's key 
is compromised, that's a different story.

____        Robert A. Hayden          <=> hayden@krypton.mankato.msus.edu
\  /__          -=-=-=-=-             <=>          -=-=-=-=-
 \/  /   Finger for Geek Code Info    <=> To flame me, log on to ICBMnet and
   \/  Finger for PGP 2.3a Public Key <=> target 44 09' 49" N x 93 59' 57" W 
- -=-=-=-=-=-=-=-
(GEEK CODE 1.0.1)  GAT d- -p+(---) c++(++++) l++ u++ e+/* m++(*)@ s-/++
		       n-(---) h+(*) f+ g+ w++ t++ r++ y+(*)


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> >   Robert A. Hayden [hayden@krypton.mankato.msus.edu] wrote:
> 
> Just to verify, I followed up to a previous posting, it wasn't mine 
> originally :-)

	Yep.. sorry about the confusion.. I wiped the first msg.. and
only had your reply to go on.  

	Now on to the topic at hand.

> Please don't take this as confrontational (ie, this is not a flame :-)

	I always associated flames with rash, unfounded accusations..
It's ok to confront.. |-]

> How would requiring that postings made to a list be verifyable be 
> censorship?  What it does is verify that REAL people posted the message 
> and that the person who's address is on the message is actually the person 
> that posted it.

	No, verifying identities [even pseudonyms] is fine.. if you
trust THE LIST.. which is also fine.. but it does leave a gap.
[note: this filter approach is similar to the Clipper chip in that
       it provides a [possibly] false sense of security -- if people
       want to filter what they see, trust in themselves and don't
       filter what other people see]

	  This also eliminates anonymous postings.
Well.. unless the filters are willing to let all messages that
are from people NOT registered with THE LIST thru.. 

> Now, granted, I suppose it could end up dumping some postings because 
> they were forged, and that is sort of censoring.  But it isn't censoring 
> based on content, but based on the fact that it appears to be a forgery.  

	If THE LIST wants to tack on a little note at the top of
every msg saying "VERIFIED AUTHOR WITH LIST DATABASE" then fine..
but don't FILTER it.  

> And by bouncing a message back to the person that posted it, you give 
> them an opportunity to repost (this time signed) in case they forgot.

	a warning from THE LIST, no less.

> Also, as for the filter idea.  If some jerk is posting a message as 
> appearing to come from schmuck@foo.bar.com, yes, I could add that address 
> to my filter and delete it before i see it, but if the jerk starts 
> posting as coming from idjit@bar.foo.com, I'd have to add another filter 
> line.

	If THE LIST can filter msgs by PGP sigs, then so can you.  It
will be no more work for you.

> By doing a check of the digital signature against the posters public key, 
> you eliminate most instances of forgery.  Of course, if the poster's key 
> is compromised, that's a different story.

	By trusting validation to just HAPPEN to your incoming mail
on some remote location is ludicrous.

In conclusion. . .  

	All too often people want to patch a problem and have it go
away.. for everyone.  Why don't we make the solution available to
everybody, not make the solution for everybody.

Nice chatting, Robert.  I'm sure I'll be seeing more.  TTFN.

> ____        Robert A. Hayden          <=> hayden@krypton.mankato.msus.edu

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> 
>   Robert A. Hayden [hayden@krypton.mankato.msus.edu] wrote:
> 
> > > Here's my two cents' worth- how about a filter on incoming mail to the list
> > > that performs these functions:
> > >   1) check the incoming post for a PGP signature
> > >   2) If a sig is found, check it against the list's public keyring
> 
> 	Hmm.. this would allow us to prove that THE LIST thinks he's
> who he says he is.. or who THE LIST tells us he is.. Now, I am not
> paranoid against THE LIST, but I suggest that THE PEOPLE should
> not filter THEIR thoughts.  What of censorship [on an aside, is there
> a censor apprenticeship?  Why the 'ship?']!?  If you must censor.. 
//               //                  //             //           //

As to why you might want to check against a list, consider it private and
a priviledge to participate in.  Another example, 'punksters decide to work
collaboratively on a project and want to restrict the exposure/discussion to
trusted list members to protect the project from outside influence/intervention,
Bottom line, don't you want to know that the person you think you are respondingto today is the same person you were communicating last week etc?  Don't you
want to keep someone from pretending to be you and sending out opinions etc.
which might damage your reputation or misrepresent you?  This is NOT censorship
i.e. it does NOT stop you from expressing your views, it only ensures that a
message which appears to be from you really IS from you.

 -Jim

--I said--
> > 	Hmm.. this would allow us to prove that THE LIST thinks he's
> > who he says he is.. or who THE LIST tells us he is.. Now, I am not
> > paranoid against THE LIST, but I suggest that THE PEOPLE should
> > not filter THEIR thoughts.  What of censorship [on an aside, is there
> > a censor apprenticeship?  Why the 'ship?']!?  If you must censor.. 

	--Jim says--
> As to why you might want to check against a list, consider it private and
> a priviledge to participate in.

	Sounds along the lines of "It's a privilage, not a right"
	[granted, this is a privately run list.. but that's not
	 what we're about.. at least that's what I've been led
	 to believe]
	
> Bottom line, don't you want to know that the person you think you are respondingto today is the same person you were communicating last week etc?  Don't you
> want to keep someone from pretending to be you and sending out opinions etc.
> which might damage your reputation or misrepresent you?  

	I want to know that the people I'm talking to are the people I
think they are.. and that is why I do my own authentication, when I can.
If I trust the machine to do it for me, then I've just shot two large
holes in my objective. [THE LIST database could me tampered with;  The
PGP sigs could be forged from the start]

> This is NOT censorship
> i.e. it does NOT stop you from expressing your views, it only ensures that a
> message which appears to be from you really IS from you.

	It IS censorship if people's posts are trashed because
they are either anonymous or a forger.. even forged posts are
sometimes important.. See my other posts regarding LIST authentication,
not filtering.

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