thank you guys couples come for this
talk when I want to present about today
is what we've been building for the past
six months
a financially accountable watching
Network and this is in calabria some of
Chris who's in the audience Sergey and
Salvatore
I wanna what I really want to highlight
is that normally when people think of
Pisa they think of all team protocols
and scalability so I've actually taken
this moment where this talk is not gonna
have anything to do of off gym protocols
whatsoever I want to highlight how P's
is generally useful for mousse top
developers cool now when I'm gonna begin
with is actually a watching network is a
misnomer there's actually two different
rules in this third-party Broadcasting
Network we have relators where our meta
transactions you know you give a
transaction to this third party and they
guarantee that it gets relayed to the
network or you have Watchers you know
these watch towers and a watch tower you
can be hired simply the watts for events
on the blockchain if there's an event it
will then respond in your behalf so
that's why it's actually a third party
broadcast network which sounds really
boring you know lol but that's actually
what it is so why do we have you know
real Ayres and responders real Ayres try
to solve the problem when the user
doesn't have access to the native token
so this could be onboarding new users
accessing coins in a contract like a
multi sake or mixing and doubling as
well where watchtowers and responders
they try to alleviate the user liveness
requirement that's to say you do an
auction
you know you submit your bid three days
later you have the reveal your bid and
you don't want to come online in three
days time so the wast Harkins is do that
in your behalf of course the main
motivations always been off team
protocols like plasma and steer channels
onion also to date availability
providers as well so what is the
perception of a third-party broadcasting
network you know how do people typically
think about it in their protocols well
first you have a user and this is the
anime edition by the way of the talk so
the user typically has a job and what
they're going to do is hire multiple
watch towers at exactly the same time
so they're gonna send the job out you
know Bom Bom Bom and then multiple Watts
Towers now have the job but the user has
to pay for multiple Watts Towers so this
sounds a bit crazy expensive doesn't it
so typically what people do instead is
that there's his own chain bounty
so the first Watts tower the salt you
know the relay the transaction and get
it in the blockchain will get the claim
this bounty so can you see the obvious
problem with this if you've hired 20
Watts Towers on they're all competing
for the same bounty you're gonna get
spams bombs bombs bombs bomb you know
only one watched how it's gonna get
rewarded and the rats are gonna have to
pay a penalty you know the gas price of
a transaction for failing to get it in
and that's not very good you know as an
illustrated example bomb you know the
reward has given in this watch tower now
they're competing for this 5k you know
$5,000 as a bounty that's fine
over the long period you make some
losses you win but if they're competing
for $5.00
that's a sucks you know who wants to
compete for $5.00 and lose money in the
long run so it's not a great way to
build these third-party watching
networks an alternative approach with
people 10 that recommend is why don't we
you know do segments so watts Tower 1
can respond by time t1 Watchtower two
can respond by t2 opto TN now the issue
here is that is really awkward to
enforce either your smart contract
considers is up front or you somehow try
to enforce is an altar monitor which
doesn't really work either so I've never
really considered this as a real valid
solution to the problem and then the
worst case scenario you guys hire 20
Watchers and nobody responded and your
transaction has never relayed maybe you
lost the auction you lost money in your
steer channel well there's no evidence
there's no recourse nothing so I really
sucks this from a user perspective you
can't blame anyone because they didn't
do their job so why do we always think
this is the best way that builders third
party broadcasting network it was
actually really frustrating because it's
clearly awkward and
doesn't work that well you know come a
little animate gift there so from the
end user perspective why are we trying
to design these third-party relay
networks in this fashion so what are the
goals that were trying to achieve
typically we're trying to minimize trust
we don't want to blindly trust a single
party to respond on our behalf and also
for the availability of Broadcasters if
I hire 22 Watchers hopefully ones at
least online to complete the job for me
but well most people seem to forget
about as accountability you know if the
watch tower doesn't do the job for me
can I prove that and can I hold them
accountable so this is basically what
we're building a Pisa
safe announce the accountable
third-party Broadcasting Network so now
I'm going to start my talk cool so what
is Pisa basically we have this
broadcaster he has skin in the game and
coins locked up on the blockchain and
there's a piece of contract which is
effectively the service level agreement
between the tower and the customer now
when the customer hires Pisa you send
the job the Pisa and in return the
customer will get a signed receipt so
now they have you know cryptographic
evidence that they're actually hired
Pisa or a watch tower so what type of
job can Pisa accept both it can be a
real layer you know these meta
transactions and it can be a responder
it can watch for events and respond on
your behalf and of course the way I will
look like is you know Alice and Bob do
something Alice hires Pisa Alice goes
offline if there's an event on the
blockchain then Pisa will simply respond
in Alice's behalf then Alice can come
back online later and then she can you
verify the peas and the watchtower
actually did his job now the question is
what a Pisa didn't respond what a Pisa
didn't do the job and didn't protect the
customer you know when it when it
promised it would can we do anything
about that
and that's exactly what peas is trying
to solve Pisa is a trust minimized
you know third-party broadcaster because
it has pronounced reliability the user
has a signed receipt that they hired
this watcher on they have on she and
evidence that Pisa didn't do its job you
simply submit both pieces of evidence to
the Pisa contract
whoops then the Pisa contract will look
at the evidence evaluate it and say yep
Pisa didn't do his job so now it forces
his refund period and there's two
outcomes either alice is refunded a pre
agreed amount that was you know
specified in the signed receipt or pisa
is eventually sloshed
so Pisa issues the refund really
straightforward you send the money you
know that challenge is cancelled and
everyone's happy so I got one question
here who's ever sent a transaction to
the network that lingered for six hours
there we go look at these year old top
developers definitely now what would be
nice is if it lingers for six hours
you're gonna get a $20 refund from Pisa
you know you're gonna have a little
smile in your face cuz you made money
for that for the body wax use your
experience anyway if Peter doesn't give
you that twenty dollar refund well you
know blocks keep ticking pisac is
slashed and pieces it will loses money
and be very upset and that's the basic
principle about but I you know behind
this now what does this on chiyan
evidence actually look like
well first Lazar did the real a kiss
these meta transactions every Tammy hire
Pisa the real a a transaction in your
behalf Pisa will relay that via the Pisa
contract and it simply keeps a record of
every attempt okay now yep so it keeps a
record of that attempt so later on if
you come online
you know Pisa promised you this
transaction would be relayed before time
T you come online after time T you look
at the Pisa contract and there's no
record of the attempt there's no record
of the attempt he's it didn't do its job
you just send over the signed receipt
I'm Pisa gets punished so that's cool
that actually works out of the box
today on the other hand what about the
responder well in the kids of the
responder basically we have to look for
events in the other contract so let's
consider the auction we have to watch
out for you know the auction to be
triggered sorry yeah we have the Watts
out for the auction to be triggered once
it's been triggered then there's
evidence the auction was triggered and
that we didn't respond now the issue is
that this can't work today but it
requires its external contract to use
our data registry and that's not great
it's a bit invasive we want to make sure
we have seamless integrations tupiza
so for seamless integrations we have to
push for this hard fork for block top
block hash if there's you know hard fork
then we can use the transaction receipts
and a block as evidence that Pisa didn't
do its job if you wanted or more
information about that just check out
this wonderful blog post that Chris
wrote oh and I also found this emoji
I'll try to find a fork emoji so if you
want to get this in the iOS and it was
sign up to the Chien's org so what's the
current state of the PISA project you
know this is something we've been
working on for two years in terms of
designing the protocol and now we've
been trying to implement it for the past
six months what's nice is that we
envisioned it to be like an inferior
Lake API as a top developer you're
simply gonna have a very simple API like
this you tell Peter when do you need
that transaction delivered what was the
code theater and what is the contract
address you simply call the API and in
return you'll get a signed receipt and
that's awesome and right now our current
guinea pigs are connects and l4 so now
we're actually trying to do an
integration to see how well this works
and once it works everyone here can try
it out and of course if you want to find
more information about it our client
information is on an new MP MP m Jas and
everything's open source so you can just
look at this repo and you can see
exactly how Pisa works today you know
and try it locally amongst yourselves
now where's Pisa a boring tedious and
hard project actually Pisa is a high
availability reliability and fault
tolerant project what do I mean by that
so if you're a dub developer and you've
got a guarantee transactions for your
users get in the blockchain once you've
got to worry about is bumping the
feature in congestion you've got to
worry about managing the balance of
multiple hot wallis to pay for gas
managing dependent and chiyan
transactions handling block readers and
hard Forks detecting these emitted
events taking data from it and using
that as part of the response I'm one
really good example of this was defy see
ever you know if you combine if you
picked here more of the above it could
become non-trivial so device chin C ever
had a chiyan transaction but in the
chiyan the first transaction had a low
fee it had a low fee and it didn't get
in which meant the other transactions
also didn't get in so this is actually a
non-trivial problem the builds and
actually most projects have to do this
with sort of sucks has taken us four or
five months to get an alpha version that
we're sort of comfortable with and we
expected to every team to replicate this
you've already lost four or five months
of engineering time so that's exactly
why I think P's is useful for move stop
developers now what about the future of
Pisa what I really want to build is a
watching pool okay so typically when
people think about these watching
networks every all the watchers are in
competition we're actually you gonna
have a pool real there's non trusted
coordinator you know I send the job to
the Pisa server the Pisa server will
send their job to each watcher and we
get Caravan Watchers or green we get a
fully signed receipt then the sign
receipt goes out to the customer so
actually all the Watchers are watching
each other's backs
so Alisa's you know we know our service
gets tossed hopefully one remains online
there's also the motivation for n level
programming the avoid critical bugs now
what about the security clutter or
lockup
a lot of people ask about this you know
one of the me
of Pisa is that we may have to lock up
50k dollars there really sure that we
have skin in the game well it's nice is
that we can outsource that other people
can donate the money in our behalf and
they're sort of betting on our
reputation that we won't get slashed I'm
by betting on our reputation you get a
share of that revenue and we can also
just lock it up a maker and compound
then use that money to earn interest as
well there's actually quite nice you
know the money doesn't go to whist
there's a real store of all you now I
just want to finish to my takeaway
message of all of this you know talk
what makes cryptocurrency so grit you
know why are we all excited about it
from my perspective
what makes cryptocurrency so grit is
that everything is publicly verifiable
and we have a set of you know we have a
decentralized set of validators I don't
in the world can volunteer blocks in
real time if you're volunteered in a
block you can you know hold the miners
accountable you vallah date it and you
accept it or you reject it if the miners
cheat you just reject the block and what
you're actually doing is holding the
block producers pronounce the
accountable if they produce Bob blocks
and that's really cool so I guess my
motivation for the past few years and
what we're trying to now build a Pisa
has lost bringing financial
accountability to every single online
service starting with you know third
party broadcast networks we're building
this new finance the accountable therap
RT and this is what everyone in this
room should be aiming towards as well we
should be building services such that
they've you know the terms of the you
know service level agreement are easily
enforceable and verifiable we should not
blindly trust third parties we should
verify everything they do and if the
third parties deviate from the protocol
or if they cheat we should have an
ability the issue punishments you know
they make sure we hold them financially
accountable and that's actually what
makes cryptocurrency so grid you know
that's the toss is real vision of why he
built this entire system so that's
basically the end of this talk you know
our goal is to build as financially
accountable
the party broadcast network hopefully
people here realized I did not talk
about Austrian protocols whatsoever it's
generally useful for most smart
contracts and now hopefully we're going
to be I mean there's an alpha version
running already and hopefully the API
will be publicly available very soon
you