Ethereum’s Rollup-Centric Roadmap: Challenges and Solutions

Ethereum’s
rollup-centric
roadmap
has
led
to
fragmented
and
separated
blockchains,
which
has
caused
a
lack
of
value
transfer
between
rollups.
As
a
solution,
shared
sequencer
mechanisms
such
as
Espresso,
Astria,
and
Radius
have
emerged.
However,
these
solutions
introduce
new
trust
assumptions,
as
such
layers
need
their
own
security
set,
according
to
Taiko.

Crossroads

Ethereum
has
prioritized
decentralization
from
its
inception,
which
comes
with
certain
constraints
on
user
experience.
These
constraints
arise
from
the
challenges
of
designing
a
decentralized
distributed
system,
such
as
dealing
with
global
state
and
sequential
execution.
In
contrast,
other
Layer
1
(L1)
blockchains
have
opted
for
speed
and
low
cost
by
sacrificing
some
decentralization.
This
has
resulted
in
higher
hardware
requirements
for
their
validators
compared
to
Ethereum.

To
address
these
issues,
Ethereum
adopted
a
rollup-centric
roadmap
four
years
ago,
outsourcing
execution
to
rollups
to
make
the
network
more
user-friendly
until
scalability
upgrades
like
history
expiration
and
statelessness
are
implemented.
This
approach
has
enabled
Ethereum
to
achieve
an
average
of
250
transactions
per
second
(TPS)
daily.

Shared
Sequencing
Layers

Currently,
rollups
use
centralized
sequencers,
which
pose
risks
of
censorship,
liveness,
and
Miner
Extractable
Value
(MEV)
extraction.
Shared
sequencers
offer
a
decentralized
alternative,
providing
finality,
decentralization,
fast
transactions,
and
cross-chain
atomicity.
However,
shared
sequencers
introduce
an
honesty
assumption,
requiring
that
at
least
half
of
the
validators
are
honest.
If
this
assumption
fails,
the
network
may
lose
liveness,
affecting
fast
finality
and
transaction
certification.

Shared
sequencing
layers
create
a
marketplace
where
rollups
can
sell
their
blockspace
to
the
highest
bidders,
redistributing
MEV
among
all
participating
rollups.
However,
this
system
requires
a
large
number
of
participating
rollups
to
maintain
its
network
effect.
If
a
significant
participant
leaves,
it
disrupts
MEV
distribution
and
affects
the
network’s
overall
value.

Neutral
Composability:
Be
Based

Ethereum
is
considered
the
most
credible
neutral
layer
for
building
decentralized
applications.
Rollups
that
use
Ethereum
as
their
sequencing
layer,
known
as
“based
rollups,”
benefit
from
full
composability
with
Ethereum
and
other
based
rollups.
However,
based
rollups
face
challenges
such
as
a
12-second
block
time,
which
limits
transaction
speed.
Solutions
like
based
preconfirmations
and
faster
Ethereum
block
times
are
being
explored
to
address
these
issues.

Based
Preconfirmations

Based
preconfirmations
involve
using
a
subset
of
Ethereum’s
validators
to
provide
fast
transaction
confirmations
to
Layer
2
(L2)
users.
This
approach
is
currently
being
tested
successfully
on
the
Helder
testnet,
enabling
lightning-fast
transactions
on
Taiko.
However,
based
preconfirmations
do
not
inherit
Ethereum’s
full
liveness
and
security,
relying
instead
on
a
credible
commitment
from
the
current
Ethereum
proposer.

Faster
Blocks

Faster
block
times
on
Ethereum
would
benefit
based
rollups
by
reducing
the
time
required
for
transaction
finality.
The
Single
Slot
Finality
(SSF)
consensus
mechanism
is
being
considered,
which
could
finalize
each
slot
in
a
few
seconds.
However,
SSF
is
vulnerable
to
33%
inactivity
leakage,
posing
a
risk
to
network
stability.

Despite
the
potential
benefits
of
faster
block
times,
Ethereum
has
chosen
to
prioritize
decentralization
and
maintain
support
for
solo
home
stakers.
This
decision
aligns
with
Ethereum’s
long-term
vision
but
requires
careful
consideration
and
community
consensus.

Conclusion

As
rollups
become
more
popular,
fragmentation
and
isolation
pose
significant
challenges.
Shared
sequencing
layers
offer
a
solution
for
fast
finality
and
cross-chain
composability
but
introduce
new
trust
assumptions.
Based
rollups,
on
the
other
hand,
use
Ethereum’s
existing
infrastructure
but
face
challenges
with
block
times
and
revenue
models.

Future
solutions
like
based
preconfirmations
and
faster
L1
block
times
aim
to
improve
the
user
experience
without
compromising
Ethereum’s
alignment.
The
goal
is
to
create
a
scalable,
decentralized,
and
user-friendly
ecosystem
that
stays
true
to
Ethereum’s
vision.

The
choice
to
be
based
or
not
is
more
than
a
technical
decision;
it
reflects
the
direction
of
decentralized
rollup
frameworks.

Source:
Taiko

Image
source:
Shutterstock