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Description
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https://archive.devcon.org/archive/watch/6/anonymous-signalling-on-ethereum/
Semaphore is a protocol, designed to be a simple and generic privacy layer for Ethereum DApps. Using zero knowledge, Ethereum users can prove their membership of a group and send signals such as votes or endorsements without revealing their original identity. The talk will describe the protocol, the main concepts and some use cases. A simple demo will also likely be used to show how Semaphore can be used to create DApps and solve real problems in the ecosystem.
Speaker(s): Cedoor
Skill level: Intermediate
Track: ZKPs: Privacy, Identity, Infrastructure, & More
Keywords: zero-knowledge proofs,semaphore,groups
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
A
We
cannot
be
sure
if
this
quote
is
from
Banksy,
but
even
if
it
was
Anonymous,
the
message
is
still
very
important.
Invisibility
or
anonymity
is
a
superpower
because
intercouples
an
idea
from
the
density
of
its
owner
because
it
allows
flowers
to
be
thrown
without
the
identity
of
the
thrower
being
known.
So
all
talk,
ideas
are
intrinsically
connected
to
the
hotel.
Sometimes
the
message
is
more
important
than
the
messenger,
and
sometimes
preserving
the
identity
of
the
messenger
is
even
more
important.
So
anonymity
can
therefore
become
an
important
tool
because
it
limits
power.
A
A
So,
knowing
that
our
data
and
identity
are
safe,
encourages
us
to
think
freely
anonymity
safeguards
reputation.
It
is
important
that
people
are
held
accountable
for
their
actions
and
especially
for
their
mistakes,
particularly
when
these
people
have
a
lot
of
responsibility
when
they
have
an
important
role,
but
it
is
also
important
that
our
ideas
are
not
judged
based
on
who
we
are,
but
either
on
what
we
have
to
say.
Anonymity
allows
an
idea
to
be
shared,
regardless
of
its
author's
reputation,
which
allows
people
to
consider
and
evaluate
ideas
for
a
more
objective
perspective.
A
A
In
recent
years,
we
have
seen
a
constant
growth
in
the
development
and
use
of
cryptographic.
Technologies
data
knowledge
proofs,
for
example,
are
now
being
used
in
many
applications,
proving
you
have
a
certain
information
without
revealing.
The
information
itself
is
a
really
powerful
concept.
By
the
way,
these
Technologies
work
is
not
trivial
for
people
without
a
background
in
mathematics
or
cryptography.
A
A
One
of
the
reasons
why
some
people
don't
care
enough
about
privacy
and
anonymity
might
be
that
there
is
not
enough
awareness
and
education
about
how
our
data
is
used
and
why
anonymity
is
important
in
ielt
society.
So
what
can
we
do?
Then?
There
are
many
solutions,
but
I
would
like
to
focus
on
free
Solutions.
The
first
one
is
privacy
by
default,
the
right
to
privacy
is
mentioned
in
most
natural
constitutions,
but
it
has
often
been
neglected
in
the
name
of
National
Security
issues
or
to
make
the
applications
we
use
every
day.
A
Smarter
and
more
efficient
privacy
and
cryptography
should
be
the
backbone
of
the
internet.
Infrastructure
protocols
and
applications
should
be
supported.
All
user
data
by
default
and,
in
addition,
users
should
be
free
to
change
the
settings,
not
the
opposite.
Another
point
is
education,
explaining
to
people
why
privacy
is
important
and
how
we
can
build
privacy
focused
applications
are
very
valuable
challenges.
A
It
is
important
to
choose
the
right
words,
build
effective
designs
and
convey
information
as
simply
as
possible.
However,
simplify
things
is
not
enough.
Making
people
aware
of
the
technological
and
social
complexity
of
the
work
we
live
in
is
equally
important,
because
we
don't
just
want
users
to
enjoy
an
experience.
We
want
new
friends,
helping
us
build
a
new
web
free.
So
the
fear
point
is
the
developer
experience.
A
The
growth
of
our
community
and
the
adoption
of
our
technology
depend
heavily
on
how
clear
the
goals
are
and
how
easily
the
main
values
and
Concepts
can
be
conveyed.
However,
another
extremely
important
aspect
is
the
quality
of
the
code.
The
call
should
be
tested,
documented
formatted,
with
Atmos
care.
It
is
extremely
important
to
use
the
right
partners
and
to
follow
the
best
practices
like
dry
and
kiss.
A
So
developers
need
to
be
able
to
rely
on
robust,
easy
to
use
tools
that
allow
applications
to
be
built
in
a
short
time,
while
also
allowing
them
to
be
extended,
customized
and
adapted
for
the
specific
uses,
so
developer.
Experience
and
education
is
what
we
have
focused
on
in
the
last
few
months
of
work
is
some
of
her,
but
many
of
you
may
be
wondering
summer
for
his
semaphore
is
a
zero
knowledge
protocol
that
allow
people
to
join
a
group
and
then
to
send
signals
such
as
messages,
endorsements
or
votes
without
revealing
the
original
identity.
A
In
addition,
it
also
provides
a
mechanism
to
prevent
double
signaling,
which
basically
means
you
cannot
create
the
same
proof
twice
or
the
proof
cannot
be
verified.
So
what
makes
them
a
powerful
tool
is
the
Simplicity
of
the
protocol
and
the
flexibility
it
can
be
used
to
build
many
applications
like
private
voting
applications,
whistle
borrower
applications
or
the
knowledge
dials
semaphore
is
made
of
three
different
parts:
vehicle
circuits
solidity
contracts
and
JavaScript
libraries.
A
My
work
has
focused
more
JavaScript,
JavaScript
libraries
and
solidity
contracts,
so
I
would
like
to
show
you
the
main
sum
of
our
Concepts
and
how
our
libraries
and
contracts
works
and
how
they
can
be
used
to
build
private
applications.
So
creating
a
consumer
for
identity
is
the
first
step
to
interact
with
the
protocol.
Each
identity
is
made
up
of
two
secret
values:
trapdoor
and
nullifier,
and
one
public
value
commitment.
So
the
positive
hash
of
the
identity,
nullifier
and
tractor
is
called
the
identity
secret
and
the
ash
of
the
identity
secret
is
the
identity
commitment.
A
So,
although
in
this
case
we
are
not
using
asymmetric
encryption,
an
identity
commitment
can
be
considered,
something
like
an
ethereum
address.
It
is
a
public
value
used
to
represent
people
in
the
protocol
and,
in
particular,
commitments
are
used
in
some
of
our
groups
to
represent
the
identity
of
a
group
member.
The
secret
values
are
like
ethereum
private
keys
and
they
are
used
to
generate
semaphore,
zero
logic,
proofs
and
authenticate
signals.
A
You
can
generate
a
random
identity
without
passing
any
parameters
and
a
deterministic
identity.
Passing
a
secret
message
like
a
password
or
a
silent
message.
Groups
are
an
important
concept.
When
we
speak
about
privacy
and
zero
knowledge
Technologies,
they
can
be
fought
as
anonymity
sets,
and
they
are
a
way
to
establish
necessary
trust
among
participants
in
semaphora
group
can
be
people
who
have
an
account
on
some
web
tube
platforms
with
high
reputation,
employees
of
a
specific
company
voters
in
an
election
or
people
with
specific
sbts
or
nfts.
A
Essentially,
any
set
of
individuals
who
are
eligible
to
participate,
participate
in
something,
so
groups
can
can
use
several
types
of
data
structures,
but
Miracle
trees
are
particularly
efficient
since,
since
they
can
prove
that
a
leaf
belongs
to
a
tree
by
using
just
one
portion
of
that
tree.
So
some
of
our
uses
binary
medical
trees,
in
which
the
leaves
are
the
identity,
commitments
and
all
the
other
nodes
in
the
three
hard
dashes
of
their
child
nodes.
A
When
a
user
join
a
group,
their
public
identity
is
added
to
that
group's
Miracle
3,
which
is
therefore
used
to
allow
users
to
generate
proof
of
membership
and
then
send
anonymous
signals.
So
groups
can
be
created
off
chain
with
our
JavaScript
library
or
Unchained,
without
with
our
semaphore
Contours.
When
a
group
is
very
large
and
is
updated
very
frequently
and
of
chain
group
might
be
a
valuable
alternative
or
solution.
This
solution
is
cheaper,
faster,
but
tended
to
be
more
centralized.
A
On
the
other
hand,
if
you
need
correct
execution
or
sensitive
resistance,
groups
can
also
be
created
on
chain
for
each
unchain
groups.
There
is
an
admin
which
can
be
an
ethereum
address,
a
smart
contract
or
a
modific
world,
for
example.
If
you
want
to
create
a
fully
decentralized
on
chain
group,
you
could
create
a
group,
a
group
and
send
your
contract
as
admin
or
your
E3
models,
which
can
which
called
used
to
allow
people
to
join
that
group
only
if
they
own
specific,
nfts
or
sbts.
A
So
after
creating
the
identity
and
joining
a
group,
users
can
anonymously
prove
that
they
are
members
of
that
group
and
send
signals
such
as
voice
endorsements
or
any
message
signals
are
part
of
a
zero
knowledge
proof
which
must
be
generated
by
users,
preferably
in
their
home
device,
as
they
need
to
use
their
private
identity.
So
secret
values,
and
it's
something
like
client-side
encryption
in
this
case
and
it
allows
proofs
to
be
generated
in
a
protected
environment
locally.
A
A
If
that
Ash
already
exists,
also,
in
this
case
we
have
a
JavaScript
library
which
can
be
used
to
generate
proofs,
proofs
must
be
generated
of
chain
and
those
proofs
can
be
verified
on
chain
or
off
chain
off
chain,
with
our
JavaScript
library,
the
same
library
and
on
chain
with
our
smart
contract.
Also,
in
this
case,
the
way
you
use
them
depends
on
your
application
on
your
use
case,
so
verifying
kind
of
chain
proofs
allows
the
verifier
your
server
or
you
to
be
certain
of
the
validity
of
the
proof.
A
It
is
a
great
way
to
allow
people
to
build
reputation
over
time,
while
giving
them
total
control
over
how
much
they
reveal
about
themselves
in
a
given
interaction.
So
another
interesting
project
is
the
guitar,
which
is
an
anonymous
social
network
where
people
can
post
and
chat
without
using
their
real
life.
Reputation
and
temporary
Anonymous
zone
is
like
an
experiment.
A
We
have
a
booth
on
the
first
floor,
you
can
try
our
applications
and
there
is
like
there
are
like
two
applications
you
can
use
where
you
can
answer
questions
and
ask
questions
anonymously
with
one
application
and
make
art
anonymously
with
the
other
application.
Collective
art.
It's
like
an
experiment
to
allow
people
to
learn
more
about
our
Technologies
and
about
semaphore,
so
stem
of
4
is
still
in
its
early
stage
and
some
of
the
ideas
for
improving
it
are
the
following:
create
an
infrastructure
to
manage
groups.
A
So
another
point
is
create
attestations
contracts
for
decentralized
groups.
Lydia,
here
is
quite
simple:
it
is
to
create
on-chain
contracts,
smart
contracts,
where
people
can
join
groups
directly
without
any
external
approval
based
on
Unchained
attributes
like
sbts
or
nfts,
or
just
the
amount
of
money
you
have.
We
will
investigate
our
zero
knowledge,
Technologies
and
public
systems,
of
course,
and
we
will
continue
improving
the
developer
experience
and
our
documentation
website.
The
idea
is
to
create
like
an
educational
website
and
last
but
not
least,
we
want
to
create
a
strong
community.
A
A
We
will
be
really
excited
to
know
more
about
your
ideas
and
projects,
whereas
if
you
want
more
information
about
semaphore
or
if
you
have
any
questions,
please
visit
our
website
where
you
can
also
find
our
disc
the
link
of
our
Discord
server
or
come
come
to
our
touch
boot.
On
the
first
floor,
so
I
of
my
talk
has
been
helpful
and
I
really
want
to.
Thank
you
all
for
listening.