[Music]
hello hi everyone my name is Vincenzo I
work in research at l2b and today the
talk is about data availability risks
and how to make a d secure looking at it
through the lens of The l2b Da risk
framework so to start data availability
is crucial for L2
security it's um nodes need data to
reconstruct the state and Advance it and
this is important for both kind of
constructions both for ZK constructions
or optimistic constructions and the
reasons differ slightly for example for
an optimistic collup you may have a
malicious State root posted to ethereum
and you need the data to compute the
the fraud proof and invalidated while
for ZK constructions you may have a
correct State being posted to ethereum
but um without the data to prove the
ownership of your individual assets uh
your funds may be Frozen and if you take
into consideration also the possibility
that the malicious
operator uh may ask for a Rome to to
make the data Available to You funds
could be stolen also in in the ZK case
and so since the risks are critical how
do we make a daer secure and the first
thing to consider is economic security
which is definitely not a meme and it is
important for liveness so to make sure
that the data can enter The Ledger so
there is no sensorship on the D layer
and also for safety so uh that once the
data enters the Ledger is not reor away
from a for a deep reor
and this is the current state of the D
layers listed on l2b and you can see
that there are some project that have
sted assets but slashing
for non-attributable faults like data
availability withholding attack for
example is very hard in uh in Celestia
for example you would need a social Fork
which is expensive and hard to pull off
for uh aen you would need a a token Fork
but the takeaway is that most slashing
mechanisms are still untested and some
are still under development like the aen
one so how do you protect against the
most crucial kind of attack in data
availability the data withholding attack
you need data avilability sampling and
this is in production for a couple of
projects like Celestia and ail but the
Assumption of Thea availability sampling
is that there is a minimum number of
light nodes on the network that are
sampling this data and this is very hard
to verify so if if you're working on it
uh come talk to us and another thing
that is very hard is the block
reconstruction protocol so once these
light nodes sample all the data um you
want them to be able to uh communicate
peer-to-peer and reconstruct the full
block so data is is not lost and this is
still under development for most
projects
today but the DL layer is only one side
of of the equation a secure D layer
what's also important is to have a
secure da bridge and so for an external
da that um that is may be used by an
optimium or a validium you need ethereum
to receive a proof that the data was
made available on this external da layer
and this proof then needs to be relayed
to a Smart contract on
ethereum and this smart contct is called
a DA
bridge and without Bridge ethereum has
no proof of the availability so it is
very important and the bridge needs to
be integrated in the proof system of the
L2 um today there is no uh LDA L2 that
integrates with a DA Bridge which is
pretty bad but hopefully that will
improve
soon so briefly looking at what makes a
DA Bridge secure cuz we looked at the D
layer but what makes a d Bridge secure
is three main things you need to look at
the community community security so who
provides the attestation to this bridge
is it a small committee is a big one is
it your friends is it a validator
set then you need to look at relayer
failure so who can relay the da
attestations and what happens if it goes
offline or turns malicious and also
Bridge up curability so are these
attestations immutable or can someone
change the history commitments of these
da
attestations and you can see from the
red on this slide uh also there is a lot
of work to do on on the
bridges and if you're wondering about
Dax because so far we have seen external
da layers but there are also uh data
availability committees and there are
many of them some are better than others
but you can get the the full list on the
L2 be website
and if you want to find out the more
more details about this uh risk
framework you can find it on the l2b
Forum and you can scan the QR code to to
get to the
link and since I have some time left
maybe I can say that um D layers as you
have seen are have different
characteristics different risks so
despite da being cheap and some people
saying it's a DA is a commodity I think
it's important to to look at these
differences and actually take seriously
the the risk that may may come up from
from using external Das and that's it
for
today Applause
please so it is more than an important
and thank you for summing this up so
nicely in like in short minutes of
course we could talk about this for and
we need to talk right so uh please
questions we have two minutes for
questions where do I throw this
maybe you can just um say from from your
perspective from the background that you
have like in the risk management and
these kind of things how do you see how
do you see the state of of of of of this
today
right yeah this projects are pretty new
let's say they they launch may not
maximum a couple of years ago so there's
still work to do and teams are are
serious so they're working on it and
right now we have the risk frame work to
kind of get the state of how things are
at the moment and not there is no
project that is all green CU they just
started let's say I mean they've been
working on it for a long time but um
Mains are more recent uh but I'm sure
they they'll you have get better soon
yeah you have F of course I that's good
to hear H did anybody thought about any
question no
yes please raise your hands
yep please please please use the
microphone so the people on internet can
hear as well yeah so uh you know you
said that I da use is a DA services and
others are public blockchains so could
you give more comparisons of these
different kinds of Das yeah in this
slide I showed uh D layers so we divided
in two sections on on L2 be we have
public data availability providers and
custom so in the public ones we have
public blockchains like Celestia Veil um
and also agda as a DA service because
it's a it's a public layer that is meant
to support many projects using it while
on the other section you would have uh
data availabilities committees um that
usually are deeply integrated with one
single L2
okay thanks for the question and for the
answer thank you Veno again and thank El
to be to everything that you guys are
doing thank you thank you thank you guys
so Applause please for venzo yeah