Re: [Blocks-development] Authentication and Ratings

[Michael S. Jr. <bl...@ms...>]

You guys have done a great job of seeing what and why, but I think you're
failing to see how this web-of-trust thing works.  (I only understand it
because once upon a time...high school, some five years ago...I was a
wannabe black hat, and I used PGP a lot.)  This isn't bad, or a failing on
your part -- most people don't really have any need for an automated
web-of-trust because you get to know each other on IRC and trust each other
that way.

The content-rating stuff can work without a web of trust...you only get
single identities that aren't related, and you have to sort out on your own
which identities you trust and which you don't.  Joe Sixpack probably trusts
Lars more than Flaggovic, because he's Joe Sixpack.  He doesn't know any
better.

WEB OF TRUST EXPLANATION

Webs of trust are freakin complicated, but keep in mind that only the people
who are very important to the network really have to get down and dirty with
the web-of-trust, and understand all this stuff.  Joe Sixpack can accept
some intelligent defaults and merely look at the red-amber-green-blank light
next to the search result.


I'll assume you guys already understand the basics of PK encryption, and all
you need to understand is the web-of-trust stuff.  If you have trouble
understanding all this, get GPG from the BlocksNet (gnupg-w32-1.0.2.zip) or
from www.gnupg.org, read the docs, and practice using it a bit.  I'll try to
be on IRC (EFnet, #blocks) later tonight, and we can try some stuff in
practice, so you get a good feel for how it works.

And for those of you who are already familiar with how PGP implements
webs-of-trust, the goals here are different:  PGP's web-of-trust certifies
that a key belongs to a particular individual, so you call the individual on
the phone and verify their identity.  Blocks' web-of-trust certifies
trustworthiness but NOT identity:  I don't care who the person is, but he's
been <making content available> for three months now, I've downloaded it
all, and it's all been good content...so I'll certify him.  PGP certifies
identity but not trustworthiness...Blocks will certify trustworthiness but
not identity.


OK, web of trust.

WHAT IS IT?

A web-of-trust is basically a collection of files that cryptographically
sign each other.  There's two kinds of key material:  a PUBLIC KEY, which is
who you're trying to certify, and KEY SIGNATURE certificates, which affirm
to the world that person A trusts person B a certain amount.

When you see the files laying there in the filesystem, they don't look like
much.  Each key has a unique identifier (that'll be about 20 hex digits
long).  If you find that you need a key for something (like to verify a
'this is SPAM' certificate) you just do a search on that key ID.  Key
signature certificates are also files that have two identifiers in them:
the ID of the key being signed, and the ID of the key that's doing the
signing.  If you just got a new key you've never seen before, just search
for key signature certificate files that have your new key's ID and a bunch
of ??????'s so you can find all people who signed that new key.

THE WEB IS WEAVED FROM SIGNATURES

So that's how nodes interconnect:  keys sign each other.  You could imagine
individual keys as points on a tree, and signatures as lines that connect
the points.  If you don't have many signatures yet, you'll have a big cloud
of points, with just a few points tied together with signatures.  If you
have a large number of well-organized signatures, you'll see one very big
tree with a bunch of little disorganized clumps here and there.

AUTOMATIC TRUST

This tree is useful so we can pass a value along the tree without human
intervention.  In this case, the value is trust -- we want the network to
tell us that we should trust this person-we've-never-seen-before.

Or in other words...we know we trust person A, because he wrote the
software.  When the system sees that A trusts B, B trusts C, and C trusts
D...we should know that we can trust D.  (The system sees all this because
it searches for keys and key signatures for A, B, C, and D, and
cryptographically verifies all the signatures.)

So this whole thing is based on this concept:  I can pick from a short list,
people I trust with my modem time.  These people I pick will pick people
they trust...and so on.  So when I trust someone very central, perhaps
Flaggovic...I will suddenly have 2000 people on my 'trusted list'.  I could
also pick my best friend Joe Warez...but his little network of friends only
spans 10 people or so.

TRUST ISN'T FOREVER

These key certificates aren't permanent:  you can also issue a 'signature
revocation' or a 'key revocation' -- if your new best friend who distributes
all the best movies turns out to be an MPAA plant and is now distributing
spam, just issue a revocation certificate.  As long as people see your
revocation as well as your original certification, they won't trust him any
more.  And the people he trusts, and so on, also won't be trusted any more.


I should be on IRC later tonight, about 2 to 3 hours from when I send this.
I look forward to making this clearer, and doing some group-participation
stuff to make this all make sense.


BTW...I don't want to reply separately, but I agree with the loss of privacy
comment ('now I can call the FBI').  I knew there was a flaw in there
somewhere.  :)


--Michael Spencer
bl...@ms...

----- Original Message -----
From: "Erik Moeller" <mo...@sc...>
To: <blo...@li...>
Sent: Monday, July 31, 2000 1:13 PM
Subject: RE: [Blocks-development] Authentication and Ratings


> On 31 Jul 2000, at 14:12, Paul Kalupnieks wrote:
>
> > But who would want to download the contents of a whole file if the
> > quality is unknown? I know I wouldn't want to sit on a 56K modem,
> > download a 10MB file and only find out it's bogus. The rating couldn't
> > be generated by the party who added it in the 1st place, since, if
> > they're creating bogus data, the file could be marked, in the same
> > way, as being just fine.
>
> You receive announcements from every node that stores the file. In
> your local index, the metadata would be joined and displayed when
> searching for the file. e.g.:
>
> Metallica.mp3
> |- Flaggovic rates this file as: SPAM, stops at 2:32
> |- Lars rates this file as: TOP, our latest album
> |- Gnome rates this file as: CORRUPTED
>
> Regards,
> Erik
> --
> Scientific Reviewer, Freelancer, Humanist -- Berlin/Germany
> Phone: +49-30-45491008 - Web: <http://www.humanist.de/erik>
> The Origins of Peace and Violence: <http://www.violence.de>
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>
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