[Music]
hello
[Music]
Defcon so Remco from the world
foundation and I'm going to be talking
about a thing we're doing which is proof
of human otherwise known as proof of
personhood but that's a bit of a
misnomer we'll get into that and how we
do this in a private way using
Biometrics and why we need ethereum to
make that happen so quickly what is
proof of
personhood the short version is it is a
way to limit account registration to a
few ideally one per human
being um that in itself uh doesn't give
you any kind of privacy in fact it
usually gives you the opposite but you
can add a layer of zero knowledge proofs
on top of that to get a slightly richer
primitive which is being able to sign
messages as a unique Anonymous human for
example within some context you can sign
a
message proving that you are a human
being that has not signed a message in
this context before you could do let's
say hey dear project please claim my
airdrop to this addos signed Anonymous
human or dear da please allocate my
voting shares to this particular vote
signed an anonymous human or dear faras
please register my handle as belonging
to a unique human being and not a bot or
dear foraster and this is where it gets
interesting please register this other
handle as my ALT because it doesn't
necessarily mean that you're restricted
to One account per human being
you can have multiple accounts it's kind
of up to the application developer to
specify what the desired behavior is it
is a programmable primitive that we're
adding to the
blockchain what is it not it is not very
importantly a
capture a proof of personhood does not
prevent a bot from doing something it
just means that this
action was
initiated and kind of signed up of by a
specific human being so you can still
automate your
accounts now why do we want proof of
personhood at a high level AI will make
it impossible to distinguish on
behavioral features
alone at least in the digital
domain and AI fueled economic
disruptions require us to get much
better at creating human oriented
Financial Solutions to solve any
economic hardship that might happen in
the
world therefore we need to add
individuals as a programmable primitive
it is also critical to get strong
decentralization
because the only way to make sure that
many many people are involved in
consensus making is through a form of
proof of person Hub this in turn unlocks
Financial Primitives with a concept of
individuals and a lot of them have that
insurance loans pensions Universal basic
income none of these we can currently do
with programmable money because we do
not yet have programmable individuals
we're changing
that and that allows you to do cool
things that kind of I didn't even expect
when we started this like um the world
chain L2 that we just launched has
prioritized block space for humans so if
you're a human being you get priority
over the trading bots in the
sequencer and then of course there's the
basics like Cil resistance and
preventing spam
BBL now why would you not want proof of
personhood unique human can often just
be a proxy for something more precise
that is what you really want like when
it comes to let's say under
collateralized
loans you're not necessarily interested
in a unique human being you're
interested in someone's credit
worthiness and there might be better
tests for that that you could use
directly that would in the end create a
system that abstracts better what it is
aiming to do um you could also have a
like you could also Imagine a social
media platform where you don't really
care whether someone is a human or a bot
as long as they make valid meaningful
contributions to the
discussion so here again there is a
trade-off for the app developers to make
like is is proof of person not actually
what I need
here and there's kind of like a an
argument that you can make that um if
you really aim for maximal
anonymity not even the number of humans
that are currently in your system should
be transparent which is something that
of course proof of person
achieves okay now that we've covered
what it is how do we build it how is it
constructed um the main problem you
solving here is the Oracle problem
you're trying to build some information
in the platonic ideal cryptographic
trusted domain that comes from the
outside that comes in in this case from
the physical real world of
humans and solving Oracle problems
always means some form of compromise and
the question is what is the best trade
of for the specific problem you're
trying to solve the three main
approaches for proof of personhood are
Authority based where you use some
existing Authority like a government or
a email provider or a bank as a trusted
entity to have a list of all the humans
others are graph-based um these are
decentralized and here you have humans
essentially verifying other humans or
you take some approach to pair wise
distinguish humans from each other
and then turn that into a larger grab
I'll get into more details on each of
these um in a moment biometric based is
recognizing that humans have a physical
body and doing measurements on that body
to distinguish it from other
bodies now the authority based this is
the conventional solution this is what
the whole Web Two World the non crypto
World uses when they need anything
remotely resembling proof of personhood
for example when the issue you alone
they will ask you to KRC yourself using
your government issued ID and so on um
this is an advantage because this means
that the average person is familiar with
them that a lot of people have access to
these means of uh these modalities
they're easily scalable and easy to
implement the downside is that um they
are imperfect when it comes to
uniqueness passports are relatively good
but still people have multiple passports
and definitely over lifetime people
renew their
passports they also have weak
inclusivity a lot of people don't have
access to these means and of course
there is the central Authority problem
we've all heard of sim swapping phone
numbers kind of suck in general for any
kind of authentication it's also active
um you need to go through this process
you need to actually make sure that the
person presenting you the passport
matches the
document um you also need to make sure
that document itself is a valid passport
and not some copy and this becomes
substantially harder in the digital
domain and a lot of the current
solutions could do a better job on on on
these steps and if we don't deploy any
kind of zero knowledge proof methods in
here of course it's enormously revealing
in terms of privacy fortunately there
are ZK solutions for all of these and
you can get them to a very high standard
which is great
now the graph Bas ones their main
strength is it's decentralized that is
the the superpower of this particular
class of solutions the downside is that
uh the main downside is a so-called
click attack where you have a group of
bots that keep verifying each other as
real humans so you get a lot of signals
on these Bots that they're real humans
and once you have a network like that
it's very hard to get this out of your
graph based system um there's a couple
of different approaches here social
graphs is an easy one where you just go
to your friends and provide proof to
each of your friends that they're all
real humans and you collect it from your
friends and this body of evidence builds
up over time other solutions that don't
require you to reveal your circle of
friends um are based on video calls
where you either post a video of
yourself online showing that you're a
real human and then have other people
uh accept or reject that or you go into
Zoom calls with people cross verifying
each other that they are indeed in this
Zoom call and indeed are are real humans
and building the graph that way um I
think both of these are are very flawed
ultimately because we have deep fakes
it's very easy to nowadays create
realistic video
calls um it's also just an awkward
non-scalable process um one that I do
want to highlight because I just think
this is such a clever solution is um
simultaneous capture solving so the
captas I mentioned before are designed
such that only humans can solve them now
if you through a blockchain or some
other means trigger um let's say five
people to solve a capture simultaneously
now you know that there's at least five
different people
there biometric base this is the um the
strongest approach it gives you near
perfect uniqueness it is
non-transferable
you know that it is um this human and
this human
cannot give this modality away to some
other you human or cellid or so on the
weakness is it's immutable it sort of
sticks to you for your entire life which
might not necessarily be desirable you
might want to have like some ability to
reset it also relies on trusted sensor
if you need a way to capture this
biometric information and and it
requires physical interaction the other
thing is the um so false match nonmatch
rates where faces with the current
algorithms are only unique up to maybe a
million individuals and after that the
algorithms will not be able to
distinguish them
anymore um same thing with fingerprints
they're not as unique as you would want
them to be irises however have an
enormous amount of entropy in them so
they work at a world population scale
and that is the main reason uh World
went in this direction
now two common Mis misconceptions about
Biometrics I do want to address a
biometric is not a private key your
fingerprint is in in a sense not a
secret like you you leave it on every
glass of every restaurant you've ever
been to and this fingerprint is not what
is you the thing that authenticates you
is the fact that you have this
fingerprint on a real life finger
attached to a living breathing body the
second thing is um I res and retinas are
not the same thing so please get that
right if you criticize
World um world's Approach at a high
level uh we have a tiered system we
recognize that there's different
trade-offs to these um different
modalities and we offer a tier list of
what we think covers the whole spectrum
of what you might want we have the the
orb you see one right there which is a
um Hardware based biometric Iris based
system that gives you super High
guarantees but um you need to go uh find
an orb in order to sign up we're now
rolling out um a ZK NFC passport based
system that gives you high privacy and
can leverage existing national ID system
and then we have a very low tier system
that uses the tees in your mobile phones
to prove that you have a unique mobile
device now with that last year you can
nobly see the issue there uh you can
just buy more phones um and that is kind
of the thing with a tier
system you want to make your tradeoffs
as an application developer based on
what your needs are and how you want the
onboarding experience to be how did we
implement this so we make use of um
modern
cryptography um generally when state is
local or Global or public or private um
there's different things we can do but
we now have a full set of solutions here
we can kind of take any kind of problem
and come up with a very Ade
solution the high level strategy is we
take our modality uh this always starts
with some form of um trusted sensors
either The Trusted sensors are other
humans in the network or The Trusted
sensor is an U um sorry the The Trusted
sensor is an NFC chip in your passport
or it is the
orb the or uh orbs are manufactured
they're registered on chain which is how
you can verify that they are authentic
through their public key these then
produ these then interact with the
user's wallet to produce uh secret
shares in zero knowledge so we
know that all of this is done correctly
and we now have secret shares of the
modality that we can then send to a
private uniqueness solution this is
implemented using multi-party
computation uh which also runs in tees
which also goes through onchain
governance and that verifies the
uniqueness critically it does this
without ever seeing the raw modality it
only sees encrypted and processes
encrypted data in the encrypted domain
which gives you a tremendous amount of
privacy here um it really sets a new
standard then we have um as a second
layer of defense for your privacy we
don't issue you some sort of ethereum
address that is now blessed we issue you
an anonymous credential you become a
member of an onchain set that you can
zero knowledge proof membership off and
this makes it such you cannot track the
behavior of any human that signed up
through the system you cannot um
associate them to the modality that they
signed up with and so
on now already covered the orb this is
our um very sophisticated device there's
other talks about this that I recommend
go in depth to how it works I do want to
highlight a little bit about the
challenges of doing this biometric
uniqueness check in in multiparty
compute the scale is enormous we're
talking about a 24 Nvidia h100 GPU
cluster that uh requires almost a
terabyte of GPU memory and terabits of
communication bandwidth just s to
sustain the 8 million users that have
signed up at a rate of 10 new users per
second multiparty as you may know has
trust assumptions it is important that
the nodes are operated by non-colluding
um entities
for that we are working with reliable
third parties we found they operate the
notes for us the world organizations do
not have access to these
systems and as a further layer of
Defense we have uh we have developed
technology that allows us to run these
Cuda MPCs on gpus in tees so inside
trusted execution environments so that
they can prove that they're all running
the pro protocol honestly and they cross
verify each other before they even
initiate the protocol then the question
is okay what protocols are they allowed
to run can they do a uniqueness Check
Yes um maybe in the future we want other
functionality we want have people the
ability to recover their accounts
through a biometric for example that
requires some form of governance that
can then onchain sign off on what are
the allowed protocols to run which
protocols meet the
criteria for privacy and the commitments
made to the users so this is where
Modern cryptography and ethereum
specifically programmable consensus are
critical in making all of this work now
to summarize World ID offers biometric
passport and device based proof of
personhood tiers you as an app developer
can integrate this depending on your
needs we implemented all of these such
that the modality actual underlying
information never leaves the user no one
outside of the user learns about the
passwort learns about the iris or
anything else and then we have this
additional layer of zero knowledge based
anonymization on each use so even if you
have a dowo where you have a one person
one phot you will not be able to track
voting patterns of users each vote is
individually unique by
default but of course as an application
Dev developer you can ask the user if
you want different Behavior
here now covering some next steps um
we've recently rolled out mini apps
which is a good way for people that have
a a a a use case that requires proof of
personhood to immediately reach an
audience of millions um as I mentioned
we have World chain which is our L2 that
users by default get an account on and
it it is um experimen with ways that we
can integrate individuals and humanness
in how sequencers prioritize uh the
transactions and how fees are allocated
we're currently working hard on in
improving the technology of client side
proving to get really fast client side
proving so on device on on your mobile
device producing zero knowledge proofs
and we want this because there is a big
future in doing programmable zero
knowledge identity meaning that not only
can you prove Pro that you're a unique
person but you can prove things about
yourself you can prove that you're of a
certain nationality you are not of a
certain nationality or um of a certain
age and so on without revealing anything
else about
yourself um and with that I want to open
the floor for any questions thank
you all right thank you gu thank you
thank you so much for the amazing talk
we do have five minutes to go over some
of the questions that people submitted
so it would be great if you can come
here in the center yes so let's
go from the very first one at the top
what if human creates a proof and sells
it to AI as there's no identity attached
and it's zero knowledge proof there's no
consequence to sell the proof or key is
associated with
it that is correct um and that is
intentional like I said this is not a
capture this is uh you're still allowed
to have a bot operate your account but
if you were to do this um you cannot
bypass rate limits for example you would
still be a single account on whatever
system you're running it on so if you
want to bless your if you want to run a
Twitter bot as a unique human you can
but if it starts spamming the system it
is obvious that it is one
account cool and what if World ID system
gets hacked or becomes hostile on its
own AKA evb so World ID as a system is a
set of smart contracts and a self
custodial wallet um that doesn't mean
it's unhackable but it means it's
subject to the same assumptions as
hacking and ethereum hacking the
ethereum network and hacking a self-
custodial wallet um but the other
question about the orb itself is a good
one
um and the way we tackle that is like I
said through transparency in how the orb
itself operates on chain so first of all
the orb is fully open source uh open
Hardware open firmware um it has a
removal SD card so you can verify the
build and so on they're all um
registered on chain
and while the process of users and the
user signing up is entirely Anonymous
the behavior of the orb is not so it is
public how many um um signups certain
orb does and if there is any suspicious
behavior that can be flagged and the
multiparty compute setup can actually
revert these fraudulent
signups uh another question is Iris
froto hard to capture can it be scanned
when I'm sleeping no it cannot it's
actually um surprisingly hard uh the orb
um despite being open Hardware
unfortunately contains um custom Optics
uh that you can't really get off the
shelf you need to find someone
specialized in making lenses to get this
done it's it's it's a hard problem of
getting a high resolution picture of of
something the size of a sugar cube that
is bouncing around a meter and a half in
front of you uh and the ARB does it it's
quite amazing um this is a good thing
though uh because this means that there
is a strong form of uh
consent um cons yeah kind of consent in
getting your iris pictures taken it's
very hard to take Iris pictures of
someone who doesn't actively and
willingly participate in the
process how does World earn income I
[Music]
pass no really um this is we we
currently don't have any uh any issues
uh here um Everything is Everything is
in production everything is running and
this is such a the space of identity is
such a gigantic opportunity that goes
Way Beyond the entire current crypto
space um and then itself the world
project will on board already onboard a
TENS of millions of people into into
blockchain but on board many many
more um how about artificial fake irises
the orb could theoretically think it
registers real humans yeah I think I
haven't covered enough how important it
is for any kind of biometric sensor to
verify that it is act it's not enough to
just take a picture of Iris or a
fingerprint you need to make sure that
this is from a real life living
breathing human body because otherwise
it could just be someone holding on an
iPad or someone trying to squish a
silicone mold on a fingerprint scanner
the the hard part in designing any kind
of biometric system is not so much the
capturing of the raw data but it is
invalidating that it is actually came
from a real human
being cool uh we have 30 seconds to go
through one more question can someone
with an orb produce IDs for non-existent
irises no the um even if you have an orb
in physical possession it is um near
impossible to to make it do those kinds
of things it it has like a very strong
amount of physical security in it and
temper protection and so on all right
cool so I think that concludes our talk
today from Rimco let's