Public SourceMage Discussion List

[Seth Alan Woolley <seth AT positivism.org>]

On Wed, Aug 31, 2005 at 08:13:37AM -0400, Sergey A. Lipnevich wrote:
> Quoting Seth Alan Woolley <seth AT positivism.org>:
> 
> >I'll explain standards however I want to.  If they are wrong, people
> >will reply thusly.  If they are correct, they will be accepted.
> 
> Unfortunately, you can't explain standards this way. If the standard 
> is ambiguous, it's not a good standard. Your explanations are taking 
> advantage of the wording that does not define certain terms, and you 
> in good faith have to acknowledge the fact that you're no a recognized 
> authority on this subject, when doing so.

The standard isn't ambigious -- "authenticate the signatory" is as clear 
as day.

> 
> >If the explanation below reinforces your point, we should dump
> >SOURCE_HASH too.
> 
> No, please see my "threat analysis" message.
> 
> >>Words like "authenticity" and "identity" run through your citings of
> >>FIPS-186. I don't want people coming to *me* to check authenticity of
> >>xyz-1.2.3.tar.bz2,
> >
> >They check the *authenticity* of the *sender*, not of the tarball.  They
> >check the *integrity* of the *tarball*.
> 
> Gotcha! When you say Nike shoes are authentic, it doesn't mean that 
> Nike is authentic. You're saying this about the thing Nike produced. 
> Us signing tarballs is like putting a seal of approval without really 
> analyzing the subject of this approval. So, fallacy of your logic is: 
> there is no such thing as authenticity of the sender, there's only 
> authenticity of the tarball.

The standard clearly states otherwise: authenticate the signatory.

The signatory is Nike.

You're confusing authentication with integrity.

An authentic painting or work of art has provenance (a process that is 
more than just looking at the signature) back to its originator (the 
person who signed the painting).  That doesn't mean the third owner 
didn't take some titanium dioxide to it and erased portions of it.  
Digital signatures thus are a bit more powerful in this regard, in that 
they can establish integrity since the signature, and they authenticate 
provenance stronger to a certain identity.  But this all takes place 
back to the signatory.  Digital signatures are stronger in a couple 
aspects, but they don't have any transcendental applications unless you 
specify it as part of the contract you are signing -- the same with a 
regular human signature.

There's absolutely no seal of approval with a digital signature.  Human 
signatures don't even have that connotion except in certain fields like 
art or Steve Wozniak's limited edition Apple IIgs (I owned one), where 
they blazoned his signature on the front of the case.

This isn't art, this is software distribution, where people seem to have 
an understanding of the situation, especially when it's _told_ to them 
by sorcery when it handles verification.  If they don't, then they'd be 
likely to interpret your hash value as a seal of approval as well -- why 
not?  It's a bunch of transcendental numbers that look random but really 
do have some vague significance.  They both have the same black hole of 
math issue that would lead one to connote transcendence.

> 
> >Let's say they do come to you to check the integrity.  Is that not what
> >happens currently with hashsums?
> 
> I want it to remain an option.
> 
> >And a HISTORY file for authentication.... Your identity!
> 
> History record doesn't mean I read the tarball.

It means you read the tarball more than a random signature on it does -- 
the signature only means you are an originator of it in an instance of 
transportation or storage.

But somebody reading the spell, seeing your name in the HISTORY, could 
get the impression while having full knowledge of how PGP operates, that 
you did in fact view it and are willing to even put it in a spell.  To 
me your argument cuts both ways.

For similar (though not exact) arguments that a signature is 
transcendental, a HISTORY entry associates you to it transcendentally 
too.

But you conveniently ignored my proposal that eliminates any possible 
transcendental association using PGP.

Here it is below: vvv Feel free to respond to it.

> 
> 
> >OK, we'll issue you a random number, the comment field links to the
> >security policy.  The name contains the number (which will most likely
> >be a hashsum of your name).  There will be no easy way for people to get
> >to your randomly issued number back to your identity unless they look up
> >a list in our security policy where they will clearly read about what
> >the signature means.  We can even throw away the index and make it hard
> >to authenticate but easy to non-repudiate.
> >
> >Then your identity isn't associated with it more than your signing of a
> >spell.  In fact, less so.

In fact, if you don't investigate the identity and accept _anything 
signed_ as transcendental (Windows users of activex have a tendency to 
do this, activex being an actual proper use of signing in your 
ideology), then you run into extreme danger again.  It's safe to tell 
the user there's zero transcendence and to let the program do the 
educating on exactly how it's used.

> >
> >>
> >>And just so I know, do you keep in mind that I am not opposing the use of
> >>signatures? I am opposing the mandatory use.
> >
> >What circumstance would make acceptable a third-party source signing by
> >a member of our team?
> 
> No, see my answers above and the "threat profile" message.

No circumstances?

Seth

-- 
Seth Alan Woolley [seth at positivism.org], SPAM/UCE is unauthorized
Quality Assurance Team Leader & Security Team: Source Mage GNU/linux
Linux so advanced, it may as well be magic http://www.sourcemage.org
Secretary Pacific Green Party of Oregon http://www.pacificgreens.org
Key id FDCEE733 = 5302 B414 64C4 6112 3454  E082 99F0 69DC FDCE E733

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