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Description
Visit the https://archive.devcon.org/ to gain access to the entire library of Devcon talks with the ease of filtering, playlists, personalized suggestions, decentralized access on Swarm, IPFS and more.
https://archive.devcon.org/archive/watch/6/on-the-path-to-a-rollup-centric-future/
It’s only been slightly over a year since Arbitrum launched as the first optimistic rollup that supported general EVM contract deployment. In that time many components have shifted, many users have migrated, and an entirely new generation of technology has shipped with Nitro. Now we look towards tackling the next set of challenges in working towards Ethereum’s rollup centric future, where using Ethereum will mean using a rollup.
Speaker(s): Harry Kalodner
Skill level: Beginner
Track: Layer 2s
Keywords: Layer-2,Rollup,Scaling
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
Very
excited
to
be
here:
Devcon
is
just
such
amazing
event,
and
you
know
the
energy
here.
It's
incredible
and
just
excited
to
be
able
to
talk
to
you
guys
today,
so
yeah
I'm,
Harry
I
am
the
CTO
and
one
of
the
co-founders
of
octane
Labs,
the
company
that
built
Arboretum
and
I'm
here
today,
I'm
going
to
kind
of
walk
you
through
a
bit
of
the
history
of
arbitrum
and
how
we
got
here
where
we
are
today
and
then
talk
some
about
sort
of
where
we're
heading
and
what
the
future
looks
like.
A
So
arbitrim
is
actually
originally
came
up
with
really
cool
history
in
2014.
Actually,
before
ethereum
had
even
launched
one
of
our
co-founders
Ed
had
the
idea
of
hey.
This
thing
is
really
cool,
but
it
doesn't
seem
like
it's
going
to
scale
now
at
the
time
it
was
very
early
and
the
idea
ended
up
sort
of
you
know
forgotten
to
history.
For
a
little
while
in
2017
we
started
working
on
it
at
the
time
we
were
at
Princeton,
University
academics
thought
hey.
A
This
is
really
cool
and
interesting,
and
it
seems
like
there
might
be
something
that'll
that'll
really
grow
here
and
we
started
out.
We
wrote
a
research
paper
back
in
2018,
it's
crazy
because
it
feels
like
yesterday
to
me,
but
it's
almost
ancient
history
in
in
crypto
time
and
then
managed
to
somehow
and
I
still
not
completely
sure
how
to
found
a
company
around
it
and
share
it
with
the
community.
So
at
that
point
we
had
this
idea.
A
We
were
building
back
in
February
2020,
just
around
East
Denver.
We
actually
had
the
first
Arbors
from
test
net.
It
was
a
lot
different
than
it
is
now.
Actually
we
started
with
technology
that
looks
a
lot
like.
It
looks
more
like
an
included
features
like
our
Nova
chain
has
today,
which
I'll
mention
a
little
bit,
but
it
was
not
a
roll-up.
It
had
a
committee,
it
had
sort
of
off-chain
agreement,
but
it
had
a
lot
of
features
like
it
has
now
and
doing
application
specific
change.
A
So,
interestingly,
sort
of
a
lot
of
where
we
are
now,
it
was
too
early
then,
but
there
was
sort
of
a
lot
of
ideas
that
have
been
bouncing
around.
That
I
think
are
now
sort
of
coming
out
as
really
popular,
and
then
we
went
from
there
we
launched
test
Nets.
We
figured
out
arbitrary
contract
deployment.
We
figured
out
arbitrary
messaging.
A
We
actually
got
our
main
net
out,
and
this
was
back
in
May
of
last
year
we
we
launched
our
mainnet
to
developers
only
we
had
a
few
months
there
and
then
in
August.
So
over
a
year
ago,
now
we
launched
on
mainnet,
and
that
is
how
we
we
ended
up.
You
know
building
Arboretum
one
getting
it
out
there.
It's
been
an
incredible
time
since
then,
but
the
building
never
stops.
A
You
know.
If
you,
if
you
stop
in
crypto,
you
might
as
well.
You
know
you're
done,
nothing
is
ever
sort
of.
You
know.
Research
always
continues.
No
technology
today
will
be
sort
of
it'll
all
look
ancient
in
five
years
and
kind
of
arbitrary
when
we
launched
already
looks
ancient
compared
to
arbits
from
where
it
is
today,
because
this
last
year
we
worked
on
our
Nitra
upgrade,
which
I'm
going
to
be
talking
about.
A
Some
today
we
launched
our
Nova
chain
which,
as
I
said,
sort
of
actually
takes
a
lot
of
ideas
from
our
original
paper
and
sort
of
the
world
is
now
I
think
in
a
position
where
they
make
a
lot
more
sense
than
they
did.
Then
we
went
through
a
really
sort
of
challenging
and
interesting
thing,
which
was
the
live
upgrade
of
our
arbitrim
chain
to
an
entirely
new
technology
stack,
and
it
was
really
interesting
to
us.
A
We
did
it
kind
of
a
couple
weeks
before
the
merge
and
it
was
essentially
our
merch
and
that,
certainly
not
not.
You
know
the
same
amount
of
coordination
necessary,
but
the
idea
of
kind
of
taking
a
technology
stack
and
somehow
well
with
a
running
system,
actually
kind
of
replaced.
The
technology
underneath
it
with
a
newer
version
with
a
more
powerful
version
that
allowed
it
to
be
cheaper,
faster.
A
A
What
does
arbitrim
provide?
Why
should
you
care-
hopefully
most
people
here
already
know,
but
it's
certainly
nice
to
say,
low-cost
transactions,
security
rooted
in
ethereum,
so,
inheriting
security,
rather
than
trying
to
have
independent
security,
which
is
really
powerful,
which
is
what
Roll-Ups
give
us
and
really
really
really
full
compatibility
with
ethereum,
which
is
the
thing
that
only
optimistic
Roll-Ups
at
least
today
can
provide
and
means
that
sort
of
tooling
languages,
everything
just
works,
and
it's
been
really
huge
for
developer
adoption.
A
A
A
This
has
got
I'm
better
with
Nitro,
as
we
added
compression
L2
costs
are
quite
low
because
of
all
the
efficiencies
of
the
system
and
the
fact
that
kind
of
the
gas
limits
can
be
quite
high,
and
so
you
can
see
we
have.
We
have
up
here
just
L2
fees,
which
is
a
very
nice
site
to
look
at.
You
can
see
that
we
are
coming
in
sort
of
just
a
couple
cents
to
to
transact.
In
the
simplest
case,
we're
doing
each
transfer
and
even
smart
contract
execution
is
very
cheap
and
easy.
A
So
I
mean
that's.
One
thing
always
to
look
at
is
essentially
each
transfer.
It's
easy
to
be
cheap,
but
also
to
be
cheap,
with
with
contract
execution,
where
users
can
use
a
lot
of
gas,
and
it
still
comes
in
cheap,
is,
is
really
really
important
and
I
think
one
of
the
areas
that
I'd
say
is
sort
of,
especially,
of
course,
this
presentation
and
the
last
one,
obviously
for
people
who
saw
both
are
covering
kind
of
you
know.
A
Similar
ideas
and
I
think
this
is
one
place
to
distinguish
optimistic
rollups
is
that
we
can
do
a
lot
of
execute
a
lot
of
computation,
a
lot
of
execution
at
very
low
cost
and
just
sort
of
for
Roll-Ups
in
general,
and
this
is
sort
of
General
across
across
DK
Roll-Ups
across
optimistic
rolls.
But
I
think
it's
really
important
to
talk
about
is
just
looking
at
sort
of
what
sort
of
what
Roll-Ups
can
give
you
versus
side
chains.
A
So
with
Roll-Ups
for
daily,
we
were
using
ethereum
and
we're
depending
on
ethereum
for
data
availability.
All
transactions
get
posted
unlike
side
chains,
where
kind
of
it's.
The
data
is
separate,
maybe
they're
posting
headers
back,
but
it's
an
independent
system.
We
have
a
bite
cut
for
a
second
but
I'm
back.
A
We
have
L1
to
L2
bridging
that's
enforced
through
the
security
of
the
roll-up
and
that's
sort
of
one
of
the
most
important
features
of
Roblox
to
me
is
the
fact
that
the
is
part
of
the
system
there's
no
sort
of
independent
multi-sig,
no
independent
Bridge
mechanism.
The
bridge
is
the
roll-off
which
is
really
fundamental,
as
opposed
to
sort
of
needing
some
sort
of
messaging
layer.
A
A
It's
an
interesting
trade-off.
It
does
make
some
sacrifices
in
security.
Maybe
we
think
about
it.
Is
that
we're
not
competing
with
roles?
We
think
if
you
can
afford
a
roll
up,
you
should
use
it.
What
we're
competing
with
is
other
solutions
that
don't
have
that
level
of
security
and
try
to
provide
something
more
secure
than
they
are
now
just
a
little
bit
about
sort
of
how
Nitro
works
and
sort
of
how
to
imagine
the
system
a
lot
of
times
with
Roll-Ups,
because
it's
so
compatible
it's
kind
of
a
black
box.
A
You
have
the
RBC,
you
point
at
the
C,
you
use
it
just
like
ethereum
and
that's
it,
but
it's
really
I
think
you
know
valuable
to
really
understand.
What's
going
on
and
really
important,
so
we've
split
it
up
into
a
number
of
steps,
and
this
is
we
have
done
this
a
lot.
How
do
you
explain
this
thing?
It's
complicated.
There
are
a
lot
of
different
pieces.
I
think
the
latest
iteration
is
one
that
we're
pretty
happy
with.
So
we
start
off
by
talking
about
sequencing,
and
this
is
probably
you
know.
A
The
role
of
the
sequencer
is
one
that
sort
of
most
well
known
in
how
Roll-Ups
work
sequencer
is
a
is
a
is
a
node
that
orders
transactions.
It
receives
transactions
in
it
puts
them
in
an
order,
and
then
it
runs
them.
It
evaluates,
take
transition
function
and
it
produces
blocks
well.
That
basically
sounds
like
how
ethereum
works
if
you
replace
sequencer
with
miners,
although
for
the
sequencer
there's
one
entity
rather
than
a
lot
of
them,
the
interesting
part
is
in
parallel
or
slightly
trailing
The
Ordering
of
transactions.
A
The
sequencer
is
also
batching
and
compressing
those
transactions
and
posting
it
to
the
L1
chain.
Now
one
key
thing
to
understand
here
is
that
the
sequencer
is
not
attesting
to
State
routes.
The
sequencer
is
not
making
claims
about
what
the
result
of
executing
those
transactions
are
like.
What
the
result
is,
all
it's
doing
is
saying
this
is
this:
are
these
are
the
transactions?
So
there's
no
such
thing
as
sort
of
claiming
something
valid
you
into
that
sorry
claiming
something
invalid.
A
So
what
does
this
mean
in
terms
of
finality,
which
is
one
of
those
important
questions,
because
you
have
these
systems
and
you
have
like
you-
have
when
metamask
says:
okay,
the
transaction's
in
a
block,
but
that's
not
enough
finality.
Is
this
really
important
question,
which
is
when
can
your
transaction
be
reversed?
A
It's
one
of
the
things
that,
with
with
the
with
the
merge,
has
changed
a
lot
for
ethereum
in
very
interesting
ways
and
sort
of
arbitrum
has
its
own
notion
of
basically
how
you
can
tell
when
a
transaction
is
final,
and
so
we
split
it
up
into
three
phases.
We
have
soft
finality
where
the
sequencer
said
it's
the
order.
If
the
sequencer
is
honest,
that's
what
the
order
is,
but
you're
trusting
the
sequencer
and
so
for
many
applications.
This
is
this
is
actually
pretty
good.
A
Currently,
the
sequencer
is
being
run
by
us
long
term.
The
sequencer
will
be
decentralized
over
a
number
of
parties,
no
need
to
trust
it,
but
you
can
and
a
lot
of
people
do
after
that
is
kind
of
the
really
important
Mark
though,
which
is
when?
Can
you
actually
not
trust
the
sequencer?
Because
trust,
if
you
just
trust
it
the
whole
time
it's
a
centralized
system
and
for
particularly
for
kind
of
exchanges
for
anybody
doing
cross-chain
stuff?
A
You
really
don't
want
to
introduce
any
trust
assumptions,
and
so
for
that,
basically,
the
idea
is
that
after
the
sequencer
has
posted
a
batch
on
chain,
the
order
is
set
once
the
transaction
posting
that
batch
itself
has
L1
finality.
The
system
is
completely
deterministic,
so
any
node
off
chain
can
get
a
guarantee
of
what
the
current
state
of
the
chain
is
based
on
batches
posted,
and
so,
if
you're
familiar
with
optimistic
rollups,
we
have-
and
this
is
the
last
phase-
the
certification
process,
which
takes
seven
days.
A
The
only
thing
that's
for
is
to
prove
back
to
ethereum
what
the
result
is,
because
after
10
minutes
after
a
batch
is
posted
and
finalized
on
L1
anybody
in
the
world
looking
at
the
chain
other
than
ethereum
can
know,
and
the
reason
for
this
is
really
simple:
ethereum
can't
actually
run
all
the
transactions
because
then
it
wouldn't
be
a
roll
up
and
then
it
would
be
expensive,
ethereum's
not
running
them,
we're
using
fraud
proofs
but
off
chain.
Anybody
can
just
run
the
transactions
themselves
and
calculate
the
result.
A
So
now
that
we
have
that
down,
what
is
the
state
transition
function?
I
mentioned
it
quickly,
but
it's
sort
of
a
very
core
part,
and
that
is
basically
with
Nitro.
We
now
have
essentially
a
wrapper
around
the
kind
of
core
Geth
implementation
of
ethereum
State
transition
function,
which
means
our
functionality
can
be
essentially
identical
with
Geth.
We
don't
need
to
worry
about
Corner
cases.
A
Instead,
we
split
up
these
processes,
and
so
we
have
basically
One
Core
code
base
compiled
in
two
different
ways:
one
to
run
at
Native
speed
on
your
computer
at
exactly
the
same
speed.
Any
any
evm
chain
can
and
one
compile
to
wasm
and
used
for
proving
both
from
the
exact
same
code.
So
there's
not
there's
no
need
for
kind
of
multiple
implementations.
A
Now
it's
it's
two
years
later,
which
is
kind
of
insane,
which
is
really
kind
of
how
we
ended
up
here
and
how
I
think
the
ethereum
community
came
to
this
path,
which
is
the
idea
that
Roll-Ups
are
the
way
that
ethereum
is
going
to
scale
and
I.
Think
that's
sort
of
really
important
to
us
and
really
we
the
way
we
think
about
it
is
that
kind
of.
Yes,
there
are
multiple
different
Technologies,
yes,
we're
all
building
but
kind
of
really.
A
What
we're
doing
is
we're
empowering
ethereum
to
actually
kind
of
be
competitive
against
other
alternative
blockchains,
since
those
two
systems
in
combination
can
do
much
more
than
other
blockchains
can
do
alone
and
then
just
at
the
end,
I
wanted
to
mention.
So
what
is
Nova
I
mentioned
it
once
it's
got
this
other
system.
All
Nova
is-
and
this
is
really
cool-
is
adding
this
data
availability
committee,
so
otherwise
the
diagram
is
exactly
the
same.
It's
just
what
I
explained,
but
rather
than
batching
and
compressing
and
posting
to
L1.
A
L2B
for
anybody
familiar
has
done
an
amazing
job
with
this
and
I
would
highly
recommend
anybody
who
hasn't
to
read
through
their
security
analysis,
which
they've
done
on
all
the
major
Roll-Ups,
but
just
to
talk
about
kind
of
where
arbitrum
is
in
this
regard.
So
Arboretum
is
I,
think
right
now,
fair
to
say
the
only
optimistic
roll
up
in
production
with
fraud,
proofs
which
is
incredibly
exciting
and
which
was
we
have
been
since
launch
and
is
really
cool
to
us
to
actually
like
lead
tech.
First,
we
come
from
an
academic
background.
A
The
tech
is
important,
but
it's
not
a
full
roll
up
yet
and
I
wouldn't
want
to
consider
it
that,
because
for
arbitrum,
validation
is
currently
permissioned,
which
is
one
of
our
big
priorities
for
this
coming
year,
is
to
drop
permissioning.
Now,
it's
not
just
us,
there's
a
great
set
of
validators
I
think
actually,
in
the
coming
weeks,
we're
going
to
do
an
announcement
where
we
list
all
the
different
entities
that
are
currently
validating
the
Arboretum
chain,
but
having
it
be
fully
permissionless.
A
A
This
real
promised
future
and
the
last
one
and
I
think
this
is
sort
of
the
hardest
kind
of
com,
the
hardest
issue
and
I
think
the
biggest
the
biggest
sort
of
discussion
and
one
that's
sort
of
really
important
and
has
been
having
happening
a
lot
here
is
how
do
you
think
about
handling
critical
bugs
in
these
systems
that,
fundamentally,
this
is
sort
of
a
really
scary
process.
If
ethereum
hits
a
bug
or
Bitcoin
hits
a
bug,
they
will
fork
and
fix
that
dog,
because
it's
in
the
core
protocol
and
those
protocols
can
Fork.
A
A
There's
some
really
cool
work
being
done
around
the
ideas
of
having
multiple
provers
and
having
a
majority
of
those
provers
need
to
all
agree,
because
then,
if
one
of
them
has
a
bug
as
long
as
the
other
one
doesn't
have
the
same
bug,
then
they
can
be
checks
for
each
other.
And
if
you
have
multiple
Implement,
multiple
independent
implementations,
then
you
get
a
lot
of
the
same.
Security
benefits
that
client
diversity
has
for
ethereum.
A
B
C
Hi
Harry
thanks
very
much
just
on
the
last
topic
you
were
talking
about
about
critical
bugs
and
how
you
could
fix
them,
and
the
sort
of
issues
that
raises
I
was
thinking
about
what
Danny
was
talking
about
in
his
talk
in
the
opening
day.
You
know
minimizing
governance.
Do
you
see
any
Prospect
of
breaking
out
the
arbitrim
design
into
multiple
components
where
a
bunch
of
them
are
immutable
and
you're
able
to
restrict
the
governance
to
just
a
small
part.
A
So,
for
instance,
a
modular
stack
which
is
just
a
set
of
layers
on
top
of
each
other,
doesn't
really
help
there.
If
some
of
them
aren't
upgradable,
because
if
you
control
an
entire
layer
chances
are,
you
can
do
whatever
you
want
so
figuring
out
sort
of
what
Arrangements
there
are
to
minimize
that
I
don't
have
a
great
answer,
but
it's
a
really
interesting
area
for
work.
D
Hey
thanks
for
the
great
talk
so
asking
kind
of
like
a
spicy
question.
What
is
like
the
core
reason
why
you
are
still
maintaining
a
white
list
on
the
fraud
proofs
and
then
you
know,
if
that's
for,
like
you
know,
gath
reasons
or
like
dos
reasons
or
whatever,
is
there
a
reason
you
wouldn't
deploy?
You
know
a
version
of
like
arbitrum
on
something
like
Gourley
that
has
you
know
non-white
listed.
D
A
A
So
there's
no
there's
a
few
different
reasons.
I
think
kind
of
both
the
sort
of
performance
of
the
roll-up
protocol,
as
many
parties
come
in
and
sort
of
confidence
in
sort
of
the
underlying
fraud.
Proof
mechanisms
which
have
been
growing
over
time
are
sort
of
kind
of
core
reasons.
I
think
that
in
this
coming
year
and
I
fully
expect
within
the
six
within
the
next
six
months,
we
will
have
those
fraud
proofs
on
Main
net
as
to
why
not
gorilla
it's
an
interesting
question.