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https://archive.devcon.org/archive/watch/6/building-privacy-protecting-infrastructure/
In this talk we'll go over how to build privacy-protecting infrastructure. What is it, why do we need it and how can we build it?
We'll look at Waku, the communication layer for Web3. We'll see how it uses ZKPs to incentivize and protect the Waku network. We'll also look at Zerokit, a library that makes it easier to use ZKPs in different environments.
After this talk, I hope you'll better understand the importance of privacy-protecting infrastructure and how we can build it.
Speaker(s): Oskar Thorén
Skill level: Intermediate
Track: ZKPs: Privacy, Identity, Infrastructure, & More
Keywords: p2p,zkp,messaging
Follow us: https://twitter.com/efdevcon, https://twitter.com/ethereum
Learn more about devcon: https://www.devcon.org/
Learn more about ethereum: https://ethereum.org/
Devcon is the Ethereum conference for developers, researchers, thinkers, and makers.
Devcon 6 was held in Bogotá, Colombia on Oct 11 - 14, 2022.
Devcon is organized and presented by the Ethereum Foundation, with the support of our sponsors. To find out more, please visit https://ethereum.foundation/
A
A
So,
that's
briefly
about
the
back
in
me:
I'm,
the
director
of
research
atvac,
and
we
build
public
good
protocols
for
the
census
web
with
a
focus
on
privacy
and
communication.
We
do
applied
research
based
on
which
we
build
protocols,
libraries
and
Publications,
and
we're
also
the
custodians
of
protocols
that
reflect
a
set
of
principles.
A
So
privacy
is
the
power
to
selectively
reveal
yourself.
Its
requirement
for
freedom
is
self-determination.
Just
like
you
need
decentralization
in
order
to
get
sensorship
resistance.
You
need
privacy
to
enable
freedom
of
expression
to
build
applications
that
are
decentralized
and
privacy
predicting
you
need
the
base
layer,
the
infrastructure
itself,
to
have
these
properties.
A
We
see
this
a
lot,
it's
easy
to
make
trade-offs
at
the
application
layer
than
doing
them
at
the
base
layer.
You
can
have
custodial
Solutions
on
top
of
a
decent
size
and
non-costal
network,
where
participants
own
their
own
keys,
but
you
can't
really
do
it
Opposite
and
if
you
think
about
it,
even
something
as
basic
as
the
buildings
can
can
be
seen
as
a
form
of
privacy.
A
Protecting
infrastructure
is
completely
normal
and
obvious
in
many
ways,
but
when
it
comes
to
your
digital
realm
and
mental
models-
and
we
are
speaking
about
it-
it
hasn't
sort
of
cut
up
from
us.
Yet
for
most
people
I'm
not
going
to
go
into
too
much
detail
about
the
need
for
privacy
or
what
happens?
We
don't
have
it,
but
suffice
to
say
it's
an
important
property
for
an
open
Society.
A
When
we
have
conversations
through
peer-to-peer
offline
conversations,
we
can
talk
privately
and
we,
if
we
use
cash,
to
buy
things,
we
can
do
Commerce
privately
on
internet
great,
as
it
is
a
lot
of
forces
that
makes
it
the
natural
state
of
things
not
the
default
big.
Take
as
you
turn
users
into
commodity,
a
product
and
monetize
users,
attention
for
advertising
to
optimize
for
your
attention.
A
So
infrastructure
is
what
lies
underneath
there's
many
ways
with
many
different
ways
of
looking
it,
but
I'll
keep
it
simple.
As
per
the
original
web
free
vision,
so
you
had
a
theorem
for
computing
consensus,
Swan
for
storage
and
Whisper
for
messaging
and
vacuum
has
taken
over
the
mantle
from
whisper
and
is
a
lot
more
usable
today
than
with
than
Whisperer
was
for
many
reasons.
A
On
the
Privacy
front,
we
see
how
ethereum
is
struggling.
It's
a
big
ux
problem,
especially
when
you
try
to
add
privacy
back
on
top.
It
takes
a
lot
of
effort
and
it's
a
lot
easier
to
censor,
and
we
see
this
with
recent
actions
around
200
cache
compare
this
with
something
like
ccash
or
Monero,
where
privacy
is
there
by
default.
A
If
someone
can
easily
find
out
where
certain
validator
is
physically
located,
that's
a
problem
in
many
parts
of
the
world
being
able
to
have
stronger
privacy
protection
guarantees
will
be
very
useful
for
high
value
targets,
and
this
doesn't
even
begin
to
touch
on
so-called
apps
that
make
a
lot
of
sacrifices
in
how
they
function
from
the
way.
How
domain
Works
to
how
websites
are
hosted
and
Reliance
on
centralized
services
for
communication?
A
We
see
this
time
and
time
again,
where
centralized
single
points
of
failure.
They
work
for
a
while,
but
then
eventually
fail
and
in
many
cases
an
individual
user.
They
might
not
care
enough
and
for
platforms.
The
Lord
to
take
shortcuts
is
strong,
and
this
is
why
it's
important
to
be
principal,
but
also
pragmatic,
in
terms
of
the
trade-offs
that
you
allow
on
top
and
we'll
touch
more
on
this
when
it
comes
to
design
goals
and
around
the
modularity.
That
Vector
has
so
synonyms.
A
Proofs
are
a
wonderful
new
tool
and
just
like
smart
contracts
enable
programmable
money.
Synops
proofs
allows
us
to
express
fundamentally
new
things
in
line
with
the
great
tradition
of
trust
minimization,
you
can
prove
statements
while
revealing
the
absolute
minimum
information
necessary,
and
this
fits
the
definition
of
privacy.
The
power
to
selectively
reveal
yourself
perfectly
and
I'm.
Sorry,
I,
don't
need
to
tell
anyone
in
this
room,
but
this
is
truly
revolutionary
and
technology
is
advancing
extremely
fast
and
it's
often
our
imagination
is
limit.
A
So
what
is
vacuum?
It's
a
set
of
model
protocols
for
pay
to
be
communication
as
a
focus
on
privacy,
security
and
being
able
to
run
anywhere,
and
it's
a
spiritual
successor
to
whisper
and
by
modeler
we
mean
that
you
can
pick
and
choose
protocols
and
how
you
use
them,
depending
on
constraints
and
trade-offs.
So,
for
example,
band
refuses
versus
privacy.
A
It's
designed
to
work
in
resource
restricted
environments
such
as
mobile
phones
and
Ware
browsers,
and
it's
important
that
infrastructure
meets
users
where
they
are
and
support
their
real
world
use
cases.
Just
like
you,
don't
need
your
own
Army
and
a
castle
to
have
a
private
bathroom.
You
shouldn't
need
to
have
a
powerful
always
on
node
to
get
reasonable
privacy
and
sensor
persistence.
We
might
call
this
self-sovereignty.
A
A
So
many
different
protocols
that
interact
the
evacu
relay
protocol
is
based
on
lipidwb
Goss
itself
for
p2b
messaging,
and
we
have
things
like
filter
for
band
restricted
nodes
to
only
receiver,
subsider
messes,
light
push
for
nodes
which
sort
connection
Windows
to
push
message
into
a
network
store
for
those
that
want
to
retrieve
historical
masses
and
then
on
the
payload
layer.
We
also
have
things
like
support
for
noise,
handshakes
and
key
exchange,
and
this
means
that
as
developers,
you
can
get
end-to-end
encryption
and
expected
guarantees
out
of
the
box.
A
We
have
support
for
setting
up
secure
channel
from
scratch
and
all
of
this
paced
away
for
providing
things
like
singles
double
directed
at
a
protocol
level
much
easier.
We
also
have
experimental
support
for
Multi-Device
usage.
It's
not
worth
noting
that
similar
features
have
existed
in,
for
example,
the
status
app
for
a
while.
But
with
this
we
make
it
easier
for
any
platform
using
vacuo
to
reduce
this.
There
are
a
lot
of
other
protocols
as
well
related
to
things
like
pay,
Discovery,
topic
use
and
so
on,
and
you
can
check
out
our
specs
for
more.
A
A
So
the
spam
problem,
Rises
on
the
glossop
player,
when
N1
can
overm
the
network
with
Masters
the
service.
Optimization
is
a
problem
when
nodes
don't
directly
benefit
from
reversing
of
a
certain
service.
This
can
happen
if
they
are,
for
example,
not
using
the
protocol
directory
themselves
as
part
of
normal
operation
or,
if
they're
on
social
inclined
to
provide
a
certain
service,
and
this
depends
a
lot
on
how
an
individual
platform
choose
to
use
the
network.
A
Historically
whisper
use
proof
of
work
which
isn't
good
for
heterogeneous
networks
and
things
like
peer
scoring
are
open
to
simple
attacks
and
doesn't
directly
address
spam
protection
in
an
anonymous
PHP
Network,
and
the
key
idea
here
is
to
use
Orlando
for
private
economic
spam
protection
using
CK
Snorks
I'm
not
going
to
go
into
too
much
detail
of
our
land.
Here
with
some
write-ups
on
back.dev
bison
house,
we've
been
pushing
a
lot
of
this
from
outside
and
I
believe.
A
So
our
land
stands
for
rate,
limiting
nullifier,
it's
an
anonymous
rate,
limiting
mechanism
based
on
CK
snarks.
In
my
resume
meeting
we
mean
that
you
can
only
send
n
messages
in
a
given
period
and
by
anonymity
we
mean
that
you
can't
link
link
message
to
a
publisher.
We
can
think
of
it
kind
of
as
a
voting
booth.
We're
only
allowed
to
vote
once
every
election.
A
A
Reticent
members
can
only
single
once
for
a
given
Epoch
or
externalifier,
for
example
every
10
seconds
in
Unix
time,
and
our
online
identifier
is
for
a
specific
online
app.
We
also
see
what
the
circuit
output
looks
like,
and
this
is
calculated
locally.
So
y
here
is
the
share
of
a
secret
equation
and
the
internal
nullifier
acts
as
kind
of
unique
fingerprint
for
a
given
app
user
EPO
combination.
A
How
do
we
calculate
this
Y
and
enter
the
nullifier?
This
is
done
using
Shamir
secretary
semi
secretary
is
a
based
on
idea
of
splitting
a
secret
into
shares,
and
this
is
how
we
enable
slashing
of
funds.
In
this
case,
we
have
two
shares.
If
a
given
identity
is
zero,
singles
twice
in
an
Epoch
external
fire,
A1
is
the
same
and
then
for
giving
all
an
app
inter
internal
file
also
stays
the
same.
A
A
A
It's
really
a
node
listens
to
the
membership
contract
for
new
members
and
also
keeps
track
of
relevant
metadata
and
the
Merkle
tree.
A
metadata
is
needed
to
be
able
to
take
double
signaling
and
perform
slashing
before
forwarding
a
message.
It
does
some
verification
checks
to
ensure
that
a
no
duplicate
messages
that
the
Synology
proof
is
valid
and
that
no
double
signaling
has
occurred.
A
It's
worth
noting
that
this
can
be
combined
with
traditional
PS
coding,
for
example,
things
like
duplicate
messages
or
invalid
CK
proofs
in
line
of
vacuum's
goal
of
modularity.
All
in
really
is
is
applied
on
specific
subset
of
Pub
sub
and
content
topics,
so
you
can
think
of
it
as
a
kind
of
a
extra
secure
Channel.
A
So
where
are
we
at
with
our
land
relay
deployment?
We've
recently
launched
our
second
test
net,
and
this
is
using
all
in
really
really
with
the
smart
content
on
girly.
It's
integrated
with
our
example.
P2P
chat
app,
and
it
does
so
through
three
different
clients
that
could
go
back
to
and
JS
Vector
for
browsers,
and
this
is
our
first
peer-to-peer
cross-client
tested
for
online
relay
here's
a
screenshot
of
a
short
demo
in
the
list
of
time.
A
I'm
not
going
to
do
a
demo
here,
I'll
actually
do
tomorrow
afternoon,
but
basically
this
shows
a
user
registering
in
a
browser
and
a
singling
through
jsbacco,
and
it
then
gets
relayed
to
in
vacuum.
Node
that
verifies
the
proof
and
when
more
than
one
message
is
sent
in
a
given
Epoch,
it
detects
the
spam
and
discards
it
slashing
hasn't
been
implemented
full.
Yet
in
the
client
and
his
work
in
progress
and
if
you're
curious
and
want
to
participate,
you
can
join
the
effort
on
our
vac
Discord.
A
A
Whether
you
want
a
storage,
historical
message
for
the
last
several
weeks,
Bob's
happy
to
provide
this
service
for
free
because
he's
excited
about
running
project,
protecting
infrastructure,
but
he's
using
it
and
he's
using
it
himself.
But
his
node
is
getting
overrun
by
freeloaders
and
it
feels
like
he
should
pay
something
to
continue
to
provide
a
service
so
Alice
deposits,
some
funds
in
a
smart
contract
which
registers
it
in
a
tree
similar
to
certain
other
private
settlement
mechanisms.
A
A
fee
is
taken
or
burnt
in
exchange,
he
gets
a
set
of
service
controls
and
once
he
wants
to
occur
with
some
criteria
as
he
sends.
This
is
a
bob
bob
responds
what
size
of
response
cost
and
receiver
address
and
then
Alice
then
sends
a
proof
of
Delegation
of
a
service
token,
with
a
payment
as
a
payment.
Bob
verifies
the
proof
and
resolves
the
query.
A
The
end
result
is
that
Alice
has
consumed
some
service
from
Bob
and
Bob
has
received
payment
from
this
there's.
No
direct
transaction
link
between
Alice
and
Bob
and
gas
fees
can
be
minimized
by
extending
the
period
before
settling
on
chain.
This
can
be
complemented
with
altruistic
service
provisioning.
For
example,
by
splitting
in
a
peer
pull
into
two
slots,
or
only
providing
a
few
cheap
queries
for
free
the
service,
provisioning
is
General
and
can
be
generals
for
any
kind
of
request
response.
A
The
initial
goal
is
to
get
the
best
of
both
worlds,
with
circum
solidity
and
JavaScript
on
one
hand
and
the
rust
sequences
ecosystem
on
other,
and
this
enables
people
to
leverage
circum-based
constructs
from
non-javascript
environments
for
the
online
module.
It
is
using
circum
circuits
via
Arc,
circum
and
rust
for
scaffolding.
It
exposes
a
cffi
API
that
can
be
used
for
other
system
programming
environments,
like
name
mango.
A
A
Socom
and
jsrings
is
access
to
things
like
dab
developers,
tooling,
generating
Verification
codes
circuits
and
raw
strengths.
Is
that
it's
a
system
based
and
easy
to
interface
with
other
language
runtimes
like
nimgo,
rust,
C?
It
also
gives
access
to
other
rusted
seek
ecosystems
such
as
artworks,
which
opens
the
door
for
using
other
constructs
like
Halo
2..
This
becomes
especially
relevant
for
Concepts,
where
you
might
not
want
to
do
a
sort
of
a
trust
setup
or
with
circus
or
more
complex
or
custom
and
performance
requirements
are
higher
and
so
on.
A
In
general,
with
circuit,
we
want
to
make
it
easy
to
build
and
use
Synod
proofs
in
a
multitude
of
environments
such
as
mobile
phones
and
web
browsers.
Currently,
it's
too
complex
to
write
privacy
predicting
infrastructure
with
Synology
proofs,
considering
all
the
languages
and
tools
you
have
to
learn
all
the
way
from
JavaScript
solidity
and
circum
and
how
to
write
the
circuits
to
rust.
Was
them
ffi
and
that's
not
even
touching
on
things
like
secure
key
storage
or
mobile
Dev?
A
I
also
want
to
mention
a
few
other
things.
We're
doing.
One
thing
is
protocol
specifications
and
we
think
this
is
very
important
for
peer-to-peer
infra
and
we
sell
a
lot
a
lot
of.
We
see
a
lot
of
other
products
that
claim
to
be
doing
P2P
infrastructure,
but
they
aren't
very
clear
about
guarantees
or
stable
something
is
or
the
actual
semantics
of
it.
This
makes
it
hard
to
have
multiple
implementations
to
collaborate
across
products
and
analyze.
A
Another
thing
is
Network
privacy,
so
vacuum
is
modeler
with
respect
to
private
Securities
and
there's
lots
of
knobs
to
turn
here,
depending
on
specific
deployments
and
requirements.
So,
for
example,
if
you're
running
the
full
relay
protocol,
you
currently
have
much
stronger
receive
anonymity
than
if
you're
running
a
filter
protocol
from
a
bandwidth
or
current
or
connectivity,
restricted
node.
A
A
As
part
of
this,
we're
looking
into
things
like
different
parameter
choices
and
and
more
generally
possibilities
for
low
latency
usage,
this
could
make
it
more
amendable
for
latency,
sensitive
environments,
Associated
validated
validated
privacy,
especially
under
very
specific
threat
models
in
general
theme,
is:
do
we
want
to
be
rigorous
about
the
guarantees
we
provide
under
what
conditions
and
for
what
precise
threat
models?
And
we
have
a
lot
of
specs
around
this
and
adversary
models,
and
so
on.
A
There's,
a
summary
we're
going
over
with
privacy.
Protecting
infrastructure
is
why
we
want
it
and
how
we
can
build
it
and
we've
seen
our
CK
is
a
fundamental
building
block
for
this.
We
looked
at
vacuo
the
communication
label
web
free
and
how
it
uses
serial
knowledge
proofs
to
stay
private
and
function
better.
We
also
looked
at
circuit
and
how
we
can
make
it
easy
to
do
Synology
proofs
in
different
environments.
A
B
Hello,
one
of
the
main
challenge
I
perceive
in
a
crypto
messaging,
is
the
fact
that
producers
has
instant
advised
to
pay
to
have
a
massage
broadcasted,
but
there
is
no
incentive
and
for
layers
to
distribute
it
to
Consumers.
That
much,
and
this
makes
centralized
solution,
usually
would
come
as
you
want
to
have
something
like
I,
don't
know,
metamask
to
be
able
to
relay
things
to
users
with
insurance
and
everything
which
make
it
in
return.
A
sensorship
sensitive.
B
Where
then
nation
state
can
pressure,
be
centralized
actors
into
not
Distributing
the
message,
and
if
you
rely
only
on
peer-to-peer,
you
might
still
need
then
some
very
old-fashioned
index
or
layer
which
can
also
be
centralized
to
this
message
is
here.
So
how
do
you
specifically
in
your
protocol,
solve
this,
making
sure
that
there
is
instances
of
a
distributor
to
receive
a
message
so.
B
Question
so,
if
you're
in
a
decentralized
messaging
protocol,
you
have
consumers
that
want
to
receive
sage,
and
as
you
put
it
yourself,
sometimes
I,
don't
really
have
a
lot
of
resource.
They
don't
necessarily
want
to
verify
their
identity
and
everything.
But
there
is
no
direct
incentive
for
broadcasters
to
have
of
the
product
message
that
these
consumers
want
to
send
this
message
to
the
consumers
if
I'm
not
getting
paid
for
it.
Yes,.
A
A
But
when
we
look
at
the
real
Network
just
like,
if
you
look
at
gossip
sub,
usually
the
participants
in
the
network
are
incentivized
to
sort
of
relay
message
and,
furthermore,
because
of
for
anonymity
reasons,
we
are
encouraging
the
use
of
a
single
pop
sub
topic,
which
means
that
sort
of
your
reeling
messages
in
a
network
in
general,
because
you
don't
necessarily
know
the
contents
of
it.
So
it's
kind
of
a
byproduct
byproduct
of
normal
operation.
B
A
Kind
of
like
this,
this
levels
of
it
right,
there's
different
types
of
incentives
and
they're,
really
Network
itself.
Empirically,
it's
not
a
big
problem
right
now.
It
is
definitely
a
recess
area
and
it's
not
something
that
we
are
looking
into
and
we
have
some
ideas
around
it,
but
it's
not
actually
a
high
priority.
D
A
That's
a
good
question,
so
our
land
is,
you
can
look
as
kind
of
semaphore,
but
then
more
things
when
it
comes
to
actually
preventing
double
double
double
signaling,
so
semaphore
plus
some
other
stuff
to
do
that
then
do
the
slashing
and
so
on.
As
for
the
CK,
like
CK
verification,
this
is
actually
something
that's
a
bit
different
with
this
peer-to-peer
infrastructure,
because
it's
not
happening
normally
on
the
blockchain.
It's
actually
you're
verifying
it
on
each
peer-to-peer,
node
sort
of
that.
That's
running
this
thing
so
that
doesn't
require
gas
usage.
A
When
it
comes
to
slash
things,
if
you've
detected
the
double
signaling,
then
you
you
have
to
go
on
chain,
obviously
and
interact
that,
and
that
will
also
verif
verify
the
proof.
But
you
can
use
the
relays
and
these
types
of
things,
but
as
part
of
normal
operation,
you're
not
actually
interact
with
blockchain.
It's
all
happening
peer-to-peer.