►
Description
A virtual meetup hosted by Hyperledger San Francisco on February 28, 2023 with Francis Mendoza speaking about Byzantine Swaps and blockchain interoperability.
Blockchain interoperability has the potential to unlock magnitudes more value from the disparate and siloed layer-one ecosystems, functionally doing for the industry what the Hypertext Transmission Protocol (HTTP) did for the fledgling internet.
The prior art for cross-chain transactions primarily involved utilization of bridges as the most popular choice, with atomic cross-chain swaps following suit. However, the fundamental security limits of bridges and the string of recent exploits block mass-adoption.
In this talk, we propose "Byzantine Swaps": a novel iteration of trustless cross-chain atomic swaps with greater security guarantees as an alternative to classical bridges and to advance security-centric interoperability developments in Blockchain R&D. We also perform a live demonstration of the cross-chain transfer of Nonfungible and Fungible assets across a Fabric-to-Fabric Network atop Hyperledger Weaver.
To learn more about Weaver, check out the Hyperledger Cacti project at: https://wiki.hyperledger.org/display/cactus
----
Hyperledger – Open Source Blockchain Technologies
Hyperledger is an open source community focused on developing a suite of stable frameworks, tools and libraries for enterprise-grade blockchain deployments.
It serves as a neutral home for various distributed ledger frameworks including Hyperledger Besu, Fabric, Sawtooth, Indy, as well as tools like Hyperledger Avalon, Cactus and libraries like Hyperledger Aries, Ursa. Learn more about Hyperledger projects: https://www.hyperledger.org/use
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License
Creative Commons Attribution license (reuse allowed)
A
A
The
discussion
today
will
be
led
by
Francis
Mendoza,
who
is
currently
a
software
engineer
at
Ripple
and
current
and
previously
was
one
of
the
people
involved
in
La
hybridledgers
mentorship
program
last
year.
If
you're
interested
in
that
I
will
drop
a
link,
we
run
at
the
hyperliger
foundation
a
yearly
mentorship
program.
So,
if
anybody's
interested
in
getting
involved
in
that
you
can
drop,
you
can
I
just
dropped
a
link
in
the
zoom
chat.
You
can
go
to
that
page
on
the
wiki
and
find
out
more.
A
A
B
Awesome,
thank
you
so
much
for
that
introduction.
David,
going
to
start
from
the
beginning
now
and
set
the
clock
I'm
not
trying
to
minimize
this
window.
Let's
see,
okay,
excellent!
So
good
morning,
everyone
I
am
Francis.
Mendoza
and
I
will
be
presenting
on
Byzantine
swaps
my
mentorship
project
under
the
hyperledger
foundation,
mentee
ship
project.
It's
a
rigorously
secure
way
for
cross-chain
asset
exchange.
B
So
the
objectives
of
this
call
as
free
with
the
audience,
is
to
for
me
to
help
you
understand
a
sort
of
General
State
of
blockchain
interoperability,
research,
inclusive
of
its
utility
and
its
challenges.
Then
we're
going
to
explain
the
functionality
of
Byzantine
swaps
compared
to
the
prior
art
interoperability
mechanisms,
and
here
I,
have
a
quick
breakdown
of
how
this
is
going
to
go.
So
we're
going
to
talk
about
why
blockchain
interoperability
matters
we're
going
to
talk
about
the
prior
art,
interoperability
efforts
and
the
challenges
that
resulted
from
that.
B
Then
we
will
talk
about
bridges
and
atomic
cross
chain
swaps
and
how
they
work
in
detail.
We
will
then
talk
about
the
hyperledger
Weaver
project,
which
is
what
Byzantine
swaps
is
fundamentally
based
on
the
design
of
Byzantine
swaps
version
2.0,
and
it
will
open
up
to
a
quick
like
relevant
q
a
so.
Why
should
we
care
about
interoperability?
B
So
the
premise
is
that
interoper
interoperability
enables
users
to
transfer
value
and
data
between
different
blockchains,
creating
an
interconnected
network
of
blockchain
systems,
so
the
ecosystem
right
now
is
very
much
like
a
set
of
Kingdoms
or
you
know,
Game
of
Thrones
everywhere.
If
you
will,
in
which
you
know,
there's
individual
layer
ones,
there's
individual
blockchains,
which
have
their
own
sort
of
rules
and
features
that
sort
of
like
constrained
or
functional
design.
B
But
this
interoperability
research
is
crucial
because
the
currently
the
blockchain
ecosystem
is
highly
fragmented,
everybody's
sort
of
trying
to
like
run
their
own
show
here,
and
you
know
if
we
look
at
history,
Computing
history
in
particular.
This
is
very
reminiscent
of
the
time
that
you
know
the
compute
to
personal
computer.
Revolution
was
really
first
getting
started.
You
had
a
bunch
of
makers
at
IBM.
B
The
information
and
the
assets
that
are
stored
in
separate
chains
is
very
much
like
what
HTTP
did
for
the
fledgling
internet,
because
prior
to
that
we
had.
These
mainframes
are
mainly
isolated
and
they
basically
had
very
specific
tasks
and
then
with
the
Advent
of
HTTP.
We
have
something
like
this,
so
this
is
the
next
computer,
which
was
a
company
that
Steve
Jobs
started
and
once
like-
and
this
was
actually
one
of
the
first
computers.
B
I
was
actually
utilizing
HTTP
at
the
time
it
had
its
own
web
server
and
the
implications
for
that
were
immediately
seen.
But
HTTP
would
go
on
to
change
the
Computing
history
forever,
because
now,
for
the
first
time,
we
had
a
clean
transition
from
Computing,
which
was
primarily
siled
in
corporations
and
Academia
to
you
know
the
Common
Man,
in
which
anybody
you
know
can
use
their
landline
and
you
know,
connect
to
the
internet
and
access
information
and
eventually
applications
that
were
stored
on
other
computers.
So
what
engineering
benefits
does
this
concretely
give
us?
B
So
we
have
increased
transaction
speed,
enhanced
security
and
better
scalability,
but
the
end
result
is
that
blockchain
interoperability
enables
the
transfer
of
value
at
the
speed
of
information
at
machine,
speed
and
machine
scale
in
the
decentralized
zero
trust
manner,
Beyond
borders
and
if
we
remember
blockchain,
is
really
the
internet
of
value
and
in
the
best
case
there
are
no
constraints.
There
are
no
borders
and
purely
you
can
transfer
value
directly
between
peer-to-peer
and
let's
talk
about
metcalf's
law,
because
this
is
the
functional.
B
You
have
a
fax
machine
that
can
send
effects
to
a
billion
people
that
becomes
an
invaluable
asset,
and
you
know
this
phenomenon
is
basically
explains
why
things
like
social
media
networks-
and
you
know,
like
things
like
web3-
become
valuable.
They
start
off
small
and,
as
they
continue
to
aggregate
more
and
more
nodes
in
the
network,
more
and
more
users.
The
value
increases
over
time,
because
you
know
the
amount
of
information
that
can
be
captured.
B
B
Useful
I
mean
I'm,
really
quite
excited
about
what
that
means,
because
if
we
were
able
to
merge
into
Worlds
of
web
2
and
web3
you
based
on
the
you
know
many
advances
that
we
have
in
this.
You
know
blockchain
interoperability
field.
We
can
really
unlock
the
next
stage
of
the
internet
in
terms
of
value.
We
can
really
see
the
full
potential
of
web
3.0
so
now
we're
going
to
take
a
broad
overview
in
terms
of
interoperability
efforts
in
the
past,
so
there's
two
spaces
or
two
camps
functionally
speaking.
B
So
there's
a
permissionless
space
in
which
you
have
interoperability
through
protocols
right.
You
can
also
have
networks
as
the
intermediaries
themselves
or
you
can
have
technology
specific
implementations,
but
there's
also
a
permission
space
in
which
you
could
have
integration.
Frameworks
and
protocols
like,
for
example,
hyperledger,
Cactus
Weaver
and
over
Ledger,
which
is
technically,
is
what
Byzantine
swaps
Falls
within
the
realm
of
it's.
In
a
permission
space
and
it's
a
framework.
Technically,
you
can
have
a
network
as
an
intermediary
or
you
could
have
a
technology
specific
implementation,
which
is
like
some
sort
of
like
standard.
B
So
in
terms
of
the
layers
of
interoperability,
interoperability
is
not
just
a
technical
mechanism,
but
it's
it
encapsulates
many
layers
of
of
the
technology
stack,
so
you
I
mean
we
can
build
Byzantine
swaps,
but
you
also
have
to
be
very
cognizant
about
the
technical
layer,
the
syntactic
layer,
the
semantic
layer
and
and
also
the
application
layer.
As
to
you
know,
what
sort
of
applications
can
interface
with
this?
B
If
you
can
standardize
the
way
which
you
are
able
to
send
data
I
mean
the
interoperability
challenge
becomes
much
much
easier,
as
well
as
making
sure
it
complies
with
all
like
legal,
legalities
and
regulations.
Now
the
spectrum
of
blockchain
interoperability.
There
are
many
different
types
of
like
operational
Dimensions.
For
example,
you
have
networks
a
through
e
and
then
they're
transmitting
data,
for
example
in
the
application
layer,
there's
interoperation
across
different
DLT
networks,
but
the
there's
fundamental
aspects
of
concern
for
each
of
these.
B
So
there
is
a
business
consensus
model,
there's
also
the
governance
model
sort
of
constrains
like
what
you
can
basically
get
away
with
if
you're
trying
to
basically
pool
different
layer
ones
together,
you
also
have
to
take
into
account
the
scope.
Is
it
a
global
State
and
what
you're
observing
or
is
it
a
sharded
state
in
terms
of
the
state
model?
Is
it
utxo
based
like
Bitcoin
or
is
it
an
account
model
like
ethereum,
and
you
also
have
to
be
aware
of
various
Forks
that
you
know
stem
from?
B
You
know
major
platforms
like
ethereum
right.
What?
What
the
trust
model
of
that
individual
layer,
one
is
as
well
as
the
execution
model
and
because
of
the
fundamental
design
constraints
of
you
know
what
that
layer,
one
is.
Is
it
do
we
have
instant
finality
or
probabilistic
finality,
and
what
does
the
network
consensus
model
look
like?
So
basically,
we
can
make
so
like,
although
we
can
make
strides
to
you
know:
stringy
different,
disparate
layer
ones.
B
Together,
we
are
still
going
to
be
hard
Bound
by
the
technical
limitations
regarding
exactly
what
the
consensus
model
looked
like
for
each
individual
layer
one.
So
if
you
have
a
utxo
versus
a
account
model
based
layer,
one
I
mean
they're
sort
of
like
limited
leeway.
You
can
get
versus
if
they're
both
of
running
off
of
utxo.
So
there
are
three
functional
prerequisites
for
any
interoperability
mechanism.
B
You
should
be
able
to
conduct
data
sharing
asset
exchange
and
asset
transfers,
so
you
should
be
able
to
share
any
sort
of
data
between
disparate
layer,
1
networks.
You
should
be
able
to
exchange
the
asset
from
one
network
to
the
other
and
you
should
be
able
to
transfer
it
free
freely
in
return.
So
in
terms
of
the
building
blocks,
so
we
have
a
claim
in
which
any
sort
of
cross-network
process
interdependency
can
be
realized.
B
As
a
combination
of
these
three
and
basically,
it
looks
like
something
like
this
in
which,
if
you're
talking
about
asset
transfer
and
asset
exchange,
this
is
a
bi-directional
right
process,
whereas
if
you're
just
sharing
data,
this
is
a
unidirectional
read,
write
so
in
terms
of
architectures
for
General
interoperability
so
like
this
is
a
sort
of
abstraction
as
to
what
this
would
look
like.
So
you
have
one
or
more
structural
assurances
to
secondary
networks,
so
you
have
a
primary
Network,
which
is
a
relay
or
settlement
network,
but
this
is
so
you
can
imagine.
B
This
is
sort
of
like
the
Silk
Road,
in
which
it
connects
these
disparate
layer,
one
secondary
networks-
and
this
is
sort
of
like
the
data
sharing
framework
that
you
will
need
so
that
these
two
could
functionally
talk
to
each
other,
but
in
the
primary
Network,
you'll
basically
need
to
do
these
functional
things.
You'll
need
to
consolidate
resources.
B
You
need
to
make
sure
the
value
of
whatever
asset
you're
pegging
in
the
secondary
Network
gets
applied
cleanly
and
you
and
most
importantly,
you
need
to
be
able
to
relay
the
messages
for
that
value
in
data
exchange
to
the
other
secondary
Network.
So
an
example
is,
you
know,
polka
dot,
Cosmos
and
you
know
Bitcoin
side
chains
as
well,
and
the
unique
challenges
of
DLT
interoperability.
So
we
have
single
party
versus
multi-party
trust.
Again.
This
is
contingent
upon
what
the
trust
assumptions
for
each
individual
layer
one
are
as
well.
B
As
you
know,
depending
on
which
one
you
have,
you
will
have
to
sort
of
like
work
with
those
constraints.
As
to
you
know,
the
interoperation
should
not
compromise
the
invariance
of
the
networks
and
protections
against
double
spends
on
assets.
So
you
have
to
make
sure
that
if
you're
attempting
to
basically
connect,
you
know
one
layer
one
to
another,
you
need
to
make
sure.
Like
you
know
what
does
like,
how
does
a
trust
model
change
in
terms
of
and
what
sort
of
transactions
are
you
able
to
get
away
with?
B
So
now
we're
going
to
basically
talk
about
the
different
types
of
interoperability
mechanisms
that
currently
exist.
So
the
first
kind
is
everyone's
most
familiar
with
are
blockchain
bridges,
so
bridges
are
a
mechanism
that
basically
lock
up
assets
on
one
blockchain
to
be
transferred,
basically
an
equivalent
on
the
counterparty
blockchain.
B
So
the
key
stipulation
for
a
blockchain
bridge
is
that
there
is
always
going
to
be
some
sort
of
into
intermediary
here,
which
sort
of
facilitates
all
the
data
transfer
into
the
asset
handling
so,
and
there
are
many
different
offshoots
of
blockchain
bridges,
so
the
the
most
important
functional
property
is
a
third-party
intermediary
of
some
kind
and
because
of
this
sort
of
like
Central
inherent
centralization
and
which,
like
there
is
sort
of
like
a
base
component,
there's
a
core
component.
That's
responsible
for
the
exchange
of
data
to
transfer
that
asset.
You
basically
have
greater
flexibility.
B
It's
much
easier
to
integrate
disparate
layer
ones,
because
all
they
have
to
do
is
basically
plug
into
this.
Like
Bridge
ecosystem
that
already
existed,
and
it's
much
great
easier
to
get
throughput,
because
this
is
a
sort
of
like
you
can
imagine
it
as
like.
Blockchain
bridges
are
like
super
highways
in
which
you
can
basically
exchange
assets
between
disparate
layer
ones.
It's
just
a
it's
a
plug
and
play
platform
practically
practically
speaking
and
there's
it's
and
all
you
need
functionally
under.
B
The
hood
is
just
a
simple
locking
mechanism
that
enables
easier
support
from
our
platforms,
and
you
know
there
are
several
derivatives.
There
are
centralized
Bridges,
there
are
decentralized
bridges
and
there
are
bridges
that
fundamentally
use
Smart
contracts,
which
are
technically
an
offshoot
of
the
decentralized
bridge.
B
Now
Atomic
cross
chain
swaps
are
a
different
category
of
interoperability
mechanism
in
which
they
prioritize
decentralization
and
security
over
speed,
Slash
throughput.
So
the
general
description
is
that
you
are
able
to
enable
the
swap
of
tokens,
or
you
know,
any
sort
of
digital
asset
between
any
two
blockchain
ecosystems
directly
without
an
intermediary
and
discount.
So
there
is
no
sort
of
central
infrastructure.
B
It
is
decentralized
in
the
case
in
which
anybody's
sort
of
connecting
or
you're
trying
to
utilize
an
atomic
cross
chain
swap
they
have
their
own
sort
of
component
that
that
mirrors
out
of
the
counterparty.
Whereas
you
know
in
a
bridge,
you
don't
really
need
to
make
any
fundamental
make
a
lot
of
additions
to
the
layer,
one
in
order
to
basically
Plug
and
Play.
B
That
is
not
necessarily
the
case
with
an
atomic
cross
chain
swap
in
which,
in
this
case,
you
would
need
your
own
relay
that
and
that
basically
needs
to
be
standardized
and
needs
to
be
able
to
talk
to
your
counterparties
relay.
So
you
all
have
your
own.
So
there's
a
system
of
there's
a
principle
of
redundancy
in
this
case
in
which
every
party
or
counterparty
that's
participating
in
the
swap
has
their
own
component
and
basically
that's
enforcing
this,
like
decentralized
system
design,
standard,
so
functional
properties
of
an
atomic
cross
chain.
Swap
it's
fully
trustless.
B
So
you
do
not
require
any
third-party
intermediary
to
perform
the
exchange,
because
you're,
basically
hosting
those
components
yourself.
The
second
part,
which
is
the
most
interesting
in
my
opinion,
is
the
property
of
deterministic
rollback
so
because
of
the
stipulation.
So
this
is
an
of
the
stipulations
outlined
within
how
an
atomic
cross
chain
swap
Works,
which
is
fundamentally
built
of
a
hash
time
lock,
contract
which
I'll
explain
in
the
next
slide.
B
Basically,
the
worst
thing
that
could
happen
is
that
the
swap
will
fail
and
then
all
the
original
assets
that
were
held
in
escrow
just
get
returned.
You
know
to
their
original
owners.
So
it's
not
like
I'm
going
to
lose
all
100
of
my
Bitcoin.
It's
just
going
to
go
back
to
my
wallet,
whereas
in
a
bridge
one
of
the
like
fundamental
weaknesses
of
Ridge
is
because
it's
a
central,
it's
fundamentally
an
intermediary
that
handles
the
data
exchange.
It
handles
the
transfer
of
these
assets.
B
A
man
in
the
middle
attacks
are
very
possible
and
that's
how
basically
things
like
you
know
all
these
Bridge
hacks
are
able
to
come
in
place,
not
necessarily
like,
for
example,
Ronin.
That's,
not
necessarily
A
Fault
With,
the
bridge
itself,
I
mean
it's
sort
of
like
a
system
administration
issue,
but
the
fundamental
weakness
of
a
bridge
is
that
you
can
launch
a
man
in
the
middle
attack
and
steal
the
asset
away
from
the
party
and
the
counterparty,
whereas
in
an
atomic
cross
chain,
swap
that
is
deterministically
guaranteed
impossible.
B
B
So
the
weakness
in
this
case
or
like
the
trade-off,
is
that
there's
careful
management
of
keys
and
the
coordination
and
The
Ordering
of
the
transactions
as
you're
performing
this
cross
chain
swap
are
absolutely
critical,
which
is
why
strict
adherence
to
you
know
this
protocol,
in
which
you
follow
the
steps
you
disperse
the
hash,
lock
the
pre-image
all
in
the
proper
order
to
the
correct
party.
You
all
have
to
execute
that
seamlessly
and
perfectly
within
the
allotted
time
limit.
B
So
for
this
example
like
this
is
just
an
abstracted
diagram
of
what
an
Atomic
cross
chain
swap
looks
like
and
I'll
just
like
walk
you
through
it.
So
we
have
Alice,
Bob
and
Carol.
So
Alice
basically
wants
to
basically
buy
a
car
from
Carol,
but
she
doesn't
have
the
exact
currency
that
Carol
is
looking
for.
B
B
You
can
only
sort
of
unlock
the
asset
in
question
in
a
particular
time
step
within
the
atomic
cross
chain
swap
so
the
first
step
is
that
Alice
generates
a
pre-image
or
just
a
secret.
She
has
a
hash
of
that
secret
and
then
basically
she
sends
that
hash
to
Bob.
Basically
we're
you
know
we're
expecting
to
complete
this
transaction
within
six
steps.
Right
then,
basically,
Bob
says
does
the
same
thing
which
he
has
his
own
pre-image
his
own
secret.
B
He
sends
an
a
hash
lock
to
Carol
and
then
basically,
Carol
does
basically
a
similar
step.
She
sends
her
hash
lock
to
Alice.
So
now
all
the
power
parties
sort
of
have
their
own
hash
luck
as
to
the
sort
of
disbursement
of
the
Assets
in
question,
so
Alice
is
basically
going
to
give
altcoins.
Bob
is
going
to
give
Bitcoins
and
Carol
is
going
to
give
the
car,
and
it's
going
in
this
basically
clockwise
Direction
now
for
the
fourth
step.
B
B
She
can
reveal
the
plain
text
pre-image
to
Bob,
and
what
this
enables
Bob
to
do
is
basically
like
to
basically
eventually
for
Carol,
to
learn
the
secret
s,
so
it
basically
Works
in
Reverse
in
which
Alice
reveals
the
secret
first
and
then
you
work
backwards
and
then
the
assets
that
are
held
within
each
individual
node
in
escrow
get
dispersed.
So
in
this
case,
Alice
reveals
the
secret,
which
eventually
makes
all
the
way
to
Carol.
Carol
now
learns
a
secret.
B
She
can
use
that
secret
to
basically
it's
the
key
in
which
he
could
use
to
unlock
the
hash
lock
per
se.
So
now
she
can
transfer
the
car
to
Alice
concurrently,
you
would
have
Bob
sort
of
like
learn
s,
and
then
he
would
transfer
the
Bitcoin
to
Carol
and
then
finally,
Alice
is
able
to
transfer
that
altcoin
balance
to
Bob.
So
assuming
that
everything
executed
within
the
proper
time
step
and
assuming
that
all
the
parties
didn't
arbitrarily
deviate
from
the
protocol,
everybody
walks
away.
B
Happy
Alice
gets
a
car,
Bob
gets
altcoins
and
Carol
gets
the
equivalent
amount
in
Bitcoin,
which
is
the
only
currency
she
was
willing
to
accept
at
the
time
now.
Atomic
cross
chain
swaps
are
built
off
of
a
hash
time
lock
contract.
So
the
key
stipulation
for
an
atomic
cross
chain
swap
is
that
it
can
only
work
if
there's
sort
of
smart
contract
functionality
on
the
layer
one
and,
moreover,
that
smart
contract
has
to
be
a
high,
a
hash
time,
lock
contract.
B
So
it's
a
particular
flavor
of
smart
contract
that
basically
uses
the
two
components
we
talked
about
earlier,
a
hashtalk
and
a
time
lock.
So
yeah,
the
hash.
Lock,
you
can
un.
You
basically
are
able
to
unlock
the
smart
contract
with,
like
you
know,
a
basically
a
passphrase
and
a
Time
luck
in
which
you
know
at
this
particular
step.
B
So
this
is
an
example
of
like
a
five-step
like
hash
time
like
contract
between
like
five
different
parties,
but
the
fundamental
principle
is
the
same
in
which
each
party
is
going
to
generate
a
pre-image
and
they're,
going
to
send
a
hash,
lock
and
there's
going
to
be
a
time
lock.
That's
sort
of
like
married
to
that
hash
Block
in
which
you're
able
to
sort
of
unlock
the
particular
asset
at
a
particular
point
in
time.
So
and
basically
these
were
the
steps
that
I
described
earlier,
in
which
you
know
each
like.
B
Fundamentally,
these
are
just
repeat:
steps
like
these
steps
will
basically
get
repeated
contingent
upon
how
many
people
are
involved
in
the
transaction,
but
every
party
will
generate
a
pre-image.
They
will
hash
said
pre-image,
send
the
hash
to
you,
know
the
next
counterparty
in
line
and
then,
when
the
time
comes,
send
the
pre-image
the
raw
pre-image
directly
to
that
counterparty.
So
they
could
basically
disperse
the
asset
in
question
so
and
again,
provided
no
party
deviate
from
the
protocol,
so
you
need
an
N
Out
of
n,
like
on
a
super
majority.
B
If
anybody
violates
the
protocol,
basically
the
tri,
the
whole
transaction
will
fail
and
then
you'll
have
a
deterministic
rollback
of
so
all
the
assets
will
just
basically
disperse
back
to
their
original
owners.
In
this
case,
then
we're
going
to
talk
about
Weaver,
because
Byzantine
swaps
is
fundamentally
built
off
of
the
hyperledger
Weaver
project
so
for
context.
Hyperledger
Weaver
is
an
interoperability
framework.
It's
open
source
code
in
which
they're
able
to
connect
basically
disparate
layer,
1
blockchain
So.
Currently
it
supports
the
hyperledger
fabric,
hyperledger
Basu
and
also
R3
corta.
B
And
then
there
are
drivers
as
well
that
sort
of
like
go
in
10
with
relay
so
they
orchestrate
a
collection
of
individual
Ledger,
States,
there's
interoperation
modules,
there's
the
application
helpers
and
then
there's
the
identity
service
or
you
know
which
helps.
You
know,
ensure
that
you
are
who
you
say
you
are,
and
you
have
an
equivalent
identity,
functionally
speaking
on
the
equivalent
counterparty
blockchain
Network
right.
B
That's
why
there
is
more
work
required
in
order
to
basically
do
this
and
there's
a
decentralized
identity
management
system,
because
if
you're
not
able
to
authenticate
yourself,
I
mean
it's
very
possible
to
basically
launch
you
know
an
equivalent
like
not
man
and
middle,
they
basically
spoof
the
identity
of
who
you
claim
to
be
so
in
terms
of
protocols.
We
have
data
sharing
with
consensus
proofs.
We
have
Atomic
acid
exchanges
across
the
network
and
then
we
have
cross-network
asset
transfers.
So
this
is
sort
of
a
chart
that
basically
tells
us
what
like
the
networks.
B
We
currently
support,
as
we
mentioned
earlier,
the
data
sharing
and
sort
of
like
what
sort
of
properties
are
available
on
each
ones
and
the
reason
why
we're
doing
fabric
to
fabric,
because
it
supports
all
three
of
these
sort
of
interoperability
like
processes,
so
we
could
perform
data
sharing.
We
could
perform
asset
transfer,
we
could
perform
asset
exchange,
although
we
will
only
be
demoing
asset
exchange
today
so
and
in
terms
of
the
transaction
flows.
B
This
is
sort
of
like
what
it
would
look
like
because
as
the
atomic
cross
chain
swap
is
underway,
we
don't
necessarily
know
the
final
state
of
that
transaction.
So
technically
this
would
get
this
wouldn't
get
overwritten
per
se.
It
would
still
be
there
within
their
own
like
layer,
one
blockchain
so
as
to
how
the
transaction
progressed,
but
the
the
state
as
to
who
the
owner
of
that
asset
is,
will
change
so
basically
functionally
there's
new,
there's
a
new
block.
B
That
will
basically
say
you
know
this
Bond
or
this
sort
of
these
set
of
tokens
now
belong
to
this
wallet
address.
So
the
president
assumptions
in
hyperledger
Weaver.
So
there
is
no
explicit
or
automated
inter
network
communication.
So,
although
this
is
done
over
relays,
a
lot
of
this
is
basically
done
manually
and
there's
a
lot
of
setup
involved.
So
in
terms
of
the
future,
we're
automating
the
flow
of
Ledger
updates
across
the
networks
via
relays
and
cross-network
events
and
Byzantine
swaps
solves
part
of
this,
in
which
we
do
introduce
additional
automation.
B
So
we
could
have
sort
of
cross
chain
messaging
across
different
layers
and
there
is
no
Global
clock
per
se
in
terms
of
the
individual,
hyperledger
Weaver
components
and
in
Byzantine
swaps.
We
changed
that
by
basically
mandating
that
every
sort
of
partying
counter
party
run
their
own
ntp,
SEC
node.
So
we
were
able
to
basically
confer
it
to
confirm
that
we
are
running
on
the
correct
time.
B
We
know
where
our
clocks
are
basically
synchronized
and
subsequently
because
of
that,
we're
able
to
ensure
that
the
the
transaction
is
able
to
execute
into
correct
order.
So,
in
terms
of
the
general
sketch
of
fabric,
we
have
application
chain
code,
that's
responsible
for
locking,
claiming
and
reclaiming
the
asset,
we're
able
to
have
the
records
of
the
Pledge
asset
on
The
Ledger
in
one
of
two
ways,
so
either
in
the
interoperation
chain,
code,
namespace
or
basically
using
the
libraries
and
in
terms
of
Byzantine
swaps.
B
So
the
general
description
is
an
iterative
improvement
on
Dr
Maurice
Hurley's
original
design.
So
he
was
a
professor
from
Brown
University
who
invented
the
concept
of
an
atomic
cross
chain
Swap
and
we're
basically
adding
additional
security
guarantees
in
this
case.
So
the
additional
guarantees
that
we
add
are
both
some
of
them
are
deterministic
and
some
are
probabilistic.
B
So
now,
malicious
lock-up
attacks
are
now
impossible,
so
malicious
lock-up
attack
is
when
a
party
and
a
counter
party,
let's
say
We
Have,
Allison,
Bob
and
Alice-
continues
to
attempt
to
a
transaction
like
a
cross
chain
swap
with
Bob,
but
intentionally
fails
either.
She
continues
to
overrun
the
time
limit
allocated
for
that
swap
or
she
she
keeps
arbitrarily
deviating
from
the
protocol
every
single
time.
So
malicious
lock-up
is
functionally
a
form
of
denial
of
service.
B
In
which
that
fungible
token
or
that
nft
or
whatever
asset
you're,
trying
to
sort
of
exchange
on
the
across
blockchain
networks,
it's
basically
on
hold,
because
basically
Alice
will
continue
to
attempt
to
launch
an
atomic
cross
chain
swap
every
time
it
keeps
failing.
The
assets
will
continuously
be
held
in
escrow
in
the
hdlc
forever,
so
Maurice
Hurley.
B
He
basically
dismisses
a
malicious
lock-up
attack
because
in
an
individual
transaction
you're,
basically
going
to
give
up
if
the
transaction
is
unsuccessful,
for
so
many
for
a
certain
amount
of
times,
but
in
the
context
of
things
like
automated
market
makers
or
any
autonomous
process.
If
you
have
like
a
trading
bot,
for
example,
you
cannot
sort
of.
There
is
no
defense
for
a
malicious
lock-up
attack,
but
malicious
lock-up
attacks
are
now
impossible,
because
now
the
Byzantine
swap
framework
basically
has
a
sort
of
like
counter,
not
not
necessarily
a
trust
score.
B
But
basically
we
have
a
way
to
basically
track
if
the
number
of
requests
the.
Why
the
reason
why
they
fail
and
whether
the
reason
they
fail.
Is
it
a
communication
failure
of
some
kind
or
is
it
intentional
malice?
And
if
it
is
a
malicious,
lock
up,
attack
will
basically
Blacklist
that
particular
a
node
from
the
network
and
because
it
we're
utilizing
the
decentralized
identity
management
system
from
hyperledger
Weaver.
It
will
be
very
difficult
for
an
attacker
to
basically
just
arbitrarily
spin
up
new
identities
and
attempt
another
malicious
lock-up
again
sore.
B
Loser
attacks
for
fungible
assets
are
now
severely
amortized,
so
a
sore
loser
attack
is
basically,
when
you
know,
you're,
basically
just
taking
the
money
and
running.
So
if
I
have
a
hundred
dollars
and
I
wanted
to
trade
that
with
you
basically
the
way
we
mitigate
a
sore
loser
attack
is
we
just
send
a
large
number
of
smaller
payments,
so
I
could
send,
for
example,
10
payments
of
10
each
and
a
sore
loser
attack
is
basically
me.
B
Just
you
know,
refusing
is
just
stop
paying
basically,
so
whatever
the
difference
is
when
I
initiated
that
attack.
Basically,
you
lost
that
amount
of
money.
Whereas-
and
you
know
this
was
an
attack-
that's
been
present
in
D5
for
a
long
time,
so
the
way
that
the
risk
is
amortized
in
this
case
is
just
by
breaking
up
transactions.
However,
we
cannot
do
that
for
wholesale
transactions
in
which
they
they
occur
once
so,
for
example,
in
nft,
you
cannot
split
up
an
nft
or
a
wholesale
asset.
B
Like
you
know
the
the
car
that
Carol
sold
to
Alice
as
many
separate
transactions-
it's
it's
one
or
nothing.
So
we
can.
Although
we
can
amortize
sore
loser
tax
for
fungible
assets
like
a
token
like
Bitcoin,
we
can
make
the
risk
of
a
sore
loser
attack,
basically
amortize
it
so
much
in
which
it's
practically
infeasible
for
non-fungible
ones,
primarily
due
to
a
number
of
reasons,
both
from
a
system
and
network
security
side.
B
Basically,
you
know
check
the
boxes
as
going
through
the
next
step
of
the
process.
Part
of
the
functionality
of
Byzantine
swap
is
all
of
this
is
automated
it's
in
an
encrypted
container,
and
if
you
wanted
to
cheat
that
process,
you
would
have
to
break
into
the
encrypted
container.
You
would
have
to
arbitrarily
change
the
code.
B
You
know
to
stand
to
basically
to
basically
give
a
past
judgment
on
a
trial
right.
That's
basically
what
we're
doing
here,
but
the
Witnesses
are
randomly
selected
from
each
sort
of
disparate
layer
ones
and
as
an
attacker
gaining
like,
like
you
know,
a
super
majority
depending
on
what
your
consensus
is.
B
It's
difficult
because
not
only
we're
using
random
leader
election,
but
you
basically
need
to
have
identities
for
that
particular
node
across
each
sort
of
layer,
one
that's
being
that's
participating
in
the
in
the
Byzantine
Swap
and
the
probability
that
you
will
have
like
sort
of
nodes,
like
sort
of
like
a
super
dishonest
super
majority
of
nodes.
In
order
to
corrupt
the
witness
consensus,
stuff
is
extremely
low.
It
is
very
expensive
because,
basically,
you
will
need
whatever
number
of
nodes.
B
You
need
to
break
fault,
tolerance,
times,
k,
k
being
the
number
of
layer,
ones
that
are
participating
in
this
cross
chain.
Swap
and
the
more
you
have
the
more
computationally
difficult
it
is,
for
you
know
the
attacker
to
invest
resources
into
it,
so
we
have
a
system,
security
perspective.
We
have
a
network
security
perspective
and,
of
course,
part
of
the
systems.
We
just
have
secure
automated
execution,
so
we
have
autonomous
rollback
the
autonomous
execution
of
the
steps.
B
So
it's
sort
of
like
an
ad
hoc
formation
of
witness
consensus.
You
need
to
be
basically
very,
very
lucky
in
which
you
have
a
dishonest
super
majority
of
nodes
controlled
by
you
that
happen
to
be
there
at
the
right
time
to
basically
all
lie
on
your
behalf,
so
the
chances
that
that
happen
are
extremely
small,
and
you
know,
even
if
you
were
able
to
execute
it,
congratulations
you
basically
were
able
to
I
know,
cancel
you
know
the
an
nft
transaction
for
going
through
or
stop
somebody's
Bitcoin
being
exchanged
for
ether.
B
So
it's
like
the
the
cost
that
would
you
would
have
to
incur
in
order
to
basically
stop
one
transaction
is
ridiculously
high,
so
those
those
are
sort
of
the
fundamental
properties
of
Byzantine
swaps.
So,
in
terms
of
acid
exchange,
this
is
what
it
looks
like.
So
we
have
two
networks
here
we
have
Network
a
network
B
right
and
we
have
an
asset
M
that
belongs
to
party
X,
and
we
want
to
transfer
it
to
party
y.
B
So
basically,
we
have
these
two
networks
right
here,
both
for
the
fungible
and
non-fungible
case,
so
for
in
the
case
of
a
fungible
asset
right.
Let's
take,
for
example,
you
know
a
cbdc,
that's
perfectly
fungible
you're
able
to
basically
use
the
same
like
Atomic
like
cross
chain,
swap
asset
exchange
framework
and
you
and
for
a
non-fungible
asset.
B
With
this
hash
h
of
s
and
you
basically
you
disperse,
you
know
that
pre-image,
not
the
pre-image,
you
disperse,
the
hash
of
that
pre-image
Bob
does
the
same
thing
in
which
he
also
disperses
pre-image
back
to
Alice.
Then,
after
a
certain
amount
of
time,
they
basically
agree.
Let's
go
forward
with
the
swap
so
Alice
audits
the
agreement
before
moving
forward.
Then
she
claims
Bob's
asset
using
the
secret
asset.
Bob
gave
to
her
so
the
secret
being
the
pre-image
before
this
time,
lock
expires
and
concurrently.
B
Bob
basically
does
the
same
thing,
so
this
is
just
a
concrete
representation
of
the
abstraction
that
we
talked
about
earlier,
and
in
this
case
this
is
an
example
of
a
bond
to
cbdc
exchange.
So
before
this
is
just
an
asset
to
asset
exchange,
but
with
an
asset
exchange
across
hyperledger
Weaver,
you
can
basically
trade
job
or
exchange.
B
You
make
a
pre-image
you,
you
had
a
hash
that
pre-image,
you
disperse
it
to
the
counterparty,
but
the
only
thing-
that's
really
different
in
this
case
is
the
asset
being
exchanged
so
one
sending
over
a
non-fungible
asset,
any
other,
sending
a
fungible
asset,
so
you're
trading
a
token
for
a
bond.
In
this
case-
and
this
is
a
great-
this
is
a
more
d-
a
far
more
detailed
diagram
as
to
the
subscription
and
communication
framework
of
Weaver.
So,
basically,
imagine
like
this
diagram
is
like
one
blockchain.
B
In
this
case,
it's
fabric.
This
is
a
fabric
to
fabric
a
detail,
fabric
to
fabric
diagram,
and
all
the
communication
is
taking
place
in
between
these
relays.
These
are
the
steps
in
which
we
are
able
to
basically
subscribe
to
events,
and
description.
Subscription
to
events
is
basically,
you
know.
How
is,
is
the
atomic
cross
chain
swap
progressing
same
thing
with
the
communication
and
the
publishing
of
each
asset
so
like
they
still
use
the
same
communication
framework,
but
for
Byzantine
swaps
like
this
is
sort
of
like
the
modified
architecture.
B
For
that,
because
every
sort
of
node
party
counterparty
is
going
to
have
their
own
components
so
you're
all
going
to
have
your
own
ntp,
SEC
cluster
Damon
you're,
going
to
have
your
own
relay
you're,
going
to
have
your
own
sort
of
accounts
that
are
each
modeled
and
you
know
authenticated
across
every
layer,
one
that
you're
transacting
with-
and
this
is
the
very
simplistic
example
of
you
know
it's
just
two
blockchains
two
disparate
layer
ones
in
this
case
the
layer
ones
are
the
same.
You
have
both
have
fabric
networks,
but
basically
this
can
scale
linearly.
B
It
just
has
to
go
in
like
like
a
like
a
order
of
a
chain
and,
and
again
all
these,
this
these
slides
will
also
be
dispersed
at
the
end
of
this
presentation
as
well.
So
if
you
wanted
to
take
a
look
as
to
how
this
works
in
detail,
I
mean
you
can
look
at
the
slides
or
ask
me
questions
and
now
we're
going
to
have
a
video
demonstration.
So
technically
this
is
13
minutes
long,
but
I'm
going
to
skip
to
the
parts
that
sort
of
like
model
these
steps.
B
So
for
context.
This
is
a
we
spun
up
a
fabric
to
fabric
Network
and
hyperledger
Weaver,
and
we
pushed
code
that
actually
got
merged
into
the
hyperledger
Weaver
repository
and
we're
going
to
be
modeling.
Two
scenarios
we're
going
to
be
modeling,
the
the
swap
of
the
non-fungible
asset,
in
the
case
of
which
it
succeeds
in
which
you're
able
to
transfer
over
cleanly
and
in
the
case
which
it
fails
in
which
you
have
the
deterministic
rollback
and
in
the
case
of
a
deterministic
rollback.
B
You
know
the
assets
just
returned
to
their
their
original
owners
and
also
the
case
of
a
fungible
asset
in
which
you
know
it's
just
tokens
in
this
case.
So
this
command
is
basically
saying
you
know.
We're
going
to
like
Alice
is
going
to
lock
her
asset
and
she's,
going
to
basically
exchange
a
bond
to
Bob,
so
Bond
one
AO3,
and
you
can
basically
assume
that
the
even
sort
of
any
asset-
that's
odd,
so,
for
example,
Bond
one,
a
3
that
belongs
to
Alice
and
he
bought
any
sort
of
asset.
B
That's
even
belongs
to
Bob,
but
by
the
end
of
this
transaction
you're,
that's
going
to
basically
fall
into
the
hands
of
Bob,
so
Bob
should
have
take
basically
an
odd
numbered
asset.
So
that's
the
initialization
of
yasa
exchange.
We
use
this
terminal
to
basically
check
like
what's
happening
here,
so
we
lock.
The
asset
we
confirmed.
Alice
exists
is
the
asset.
Locked
in
response
is
true
and
the
query
has
been
complete.
B
The
gateways
has
been
disconnected,
then
we
get
the
status
of
how
the
of
where
the
asset
is
so
we're
taking
the
sort
of
status
from
each
individual.
Oh
I
accidentally
skipped
back
we're
taking
the
status
of
of
where
the
assets
lie
within
each
individual,
Network,
so
fabric
Network,
one,
that's
technically
with
Alice
and
then
you're
going
to
see
an
equivalent
record
with
Bob
as
well.
So
you
have
basically
like
these
tokens,
so
you
could
see,
for
example,
fabric
Network,
one
simple
asset.
B
We
have
Bond
one,
but
you
don't
say
a03,
because
it
has
been
moved
out
from
the
network
in
which
it
resided
in
Alice,
and
it's
now
in
locked
up
in
a
hash
time,
lock,
contract
and
until
after
60
seconds,
basically
pass
assuming
all
goes
well.
It
should
basically
return
back
to
Bob
and
basically
you
should
be
able
to
see
this
record
as
to
whose
assets
which
asset
belongs
to
who
and
then
you
have
the
fabric
Network
as
well.
B
The
fabric
Network
too,
is
basically,
this
is
taking
into
account
the
fungible
assets
in
this
particular
point
in
the
demo
we
haven't
done
fungible
yet
so
you
know,
Alice
has
10
000
tokens,
Bob
has
8
000.
and,
as
we
progress
further
here,
we're
going
to
get
run
to
network
status
again,
and
this
time
we
should
be
able
to
see
that
in
fabric
Network
one,
the
bond
has
actually
transferred
back
to
Alice
in
this
case,
because
we
overran
the
time
limit.
B
So
in
this
particular
example,
this
is
the
case
in
which
the
swap
was
not
successful.
You
over
you
exceeded
the
time
limit,
which
is
basically
an
arbitrary
violation
of
the
protocol,
and
then
we
basically
roll
back
to
the
original
owner,
so
Bond
one
of
id803
now
belongs
to
Alice,
in
this
case
it
just
rolled
back
to
her
and
technically
in
trying
to
initiate
that
transaction
again,
we're
able
to
basically
have
that
asset
transfer
cleanly
this
time.
So
basically
now
we're
reattempting
that
transaction.
B
But
in
order
to
be
successful
this
time
we
actually
progressed
in
the
next
step.
So
you
know
Alice
basically
locks
the
transaction,
and
then
this
is
the
case
in
which
Bob
basically
disperses
his
secret
text.
So
basically
Bob
is
going
forward
and
advancing
the
next
step
of
this
transaction,
whereas
you
know
Alice
Bob
just
left
Alice
hanging
before
and
it
exceeded
the
time
limit.
B
So
that's
why
the
transaction
we
had
the
deterministic
rollback
of
that
asset
as
well
so
and
we
get
the
status
of
the
asset
again
and
then
subsequently
from
this,
you
can
see.
There's
a
change
here,
this
time
in
which
now
we
have
Bond
one
and
a03,
it's
technically
listed
with
Bond
one
a04.
So
the
stipulation
earlier
about
how
Alice
owns
all
the
odd
number
assets
and
Bob
owns
all
the
even
number
Assets
Now
that
has
been
switched
because
they
are
ordered
they're.
B
Basically
now
grouped
together,
in
which
you
had
the
odd
number
assets
should
belong
to
Alice
in
one
group
and
Then,
followed
by
the
even
numbered
assets
which
belong
to
bomb,
the
other
group.
But,
as
you
could
see,
we
have
ID
a03,
which
is
basically
Alice's
asset
that
got
successfully
transferred
to
Bob,
because
it's
listed
along
with
all
the
other
assets
he
owned,
which
are
in
the
which
are
in
which
are
numbered
even
right,
which
technically
belongs
to
him.
B
So
in
this
case
that
was
the
demonstration
of
non-fungible
token
or
asset
transactions
in
the
case
of
deterministic
rollback.
If
there's
arbitrary
violation
and
what
have
happens
if
it's
a
success
and
then
we're
going
to
basically
skip
ahead
to
the
case
of
a
fungible
asset
in
this
case,
so
fungible
assets
are
basically
tokens.
So
in
this
case
we're
going
to
have
a
timeout
for
60
seconds.
B
Bob
is
going
to
be
basically
initiating
the
transaction
this
time
and
he's
going
to
send
over
167
tokens
so
that
167
tokens
gets
locked
up
in
the
hash
time
lock
contract
and,
as
you
can
see,
the
balance
hasn't
shifted
yet
because
the
balance
will
only
get
really
dispersed
once
the
sort
of
like
time
limit
has
passed,
and
you
know
once
Alice.
Actually,
you
know
proceeds
further
with
the
transaction
itself.
B
B
So
basically,
what
happens
here
is
the
deterministic
rollback
in
which,
like
okay,
well
Alice,
like
is
supposed
to
basically
disperse
her
secret
text
or,
like
you
know
her
disperse
her
pre-image,
so
that
she's
able
to
claim
the
the
fungible
assets
that
were
stored
in
that
hdlc,
but
as
we
run
the
get
status
again.
Basically,
what
happens
is
that
we're
back
to
8
000,
because
the
time
limit
took
too
long,
Alice
didn't
disperse.
B
You
could
see
the
fungible
asset
has
been
claimed
as
true
and
the
asset
is
complete.
So,
as
we
progress
forward
here,
we
should
be
able
to
basically
see
the
balance
the
difference
in
balances.
So
now
you
can
see
that
you
know
the
out
of
the
245
that
we
initial
that
Bob
was
going
to
transfer
to
Alice.
It
was
indeed
successful.
Alice
initially
had
10
000
tokens.
Now
it's
10,
245
and
Bob
has
a
new
balance
of
7755
tokens.
B
B
Thank
you
again
for
having
me
on
and
all
my
mentors
from
sort
of
like
that
sort
of
like
help
me
learn
more
about
these
prior
art
of
atomic
cross
chain
swaps
and
help
you
figure
out
exactly
how
we
could
build
upon
Maurice
Hurley's
original
design.
All
the
code
has
been
merged
to
cacti
as
a
disclaimer,
the
hyper
electric
Cactus
and
hyper-ledger
Weaver
repositories
will
be
merged
into
a
single
repository
as
hyperledger
cacti
into
future.
All
the
code
is
open
source.
B
If
you
wanted
to
check
out
the
individual,
Cactus
and
Weaver
repositories,
I've
linked
them.
Here
again,
the
slides
will
be
dispersed
ahead
of
the
presentation
and
you
will.
You
can
also
find
the
hyper-ledger
cacti
repository
as
well.
I
have
my
contact
information,
my
LinkedIn.
If
you
wanted
to
chat,
and
now
we
will
open
it
up
to
q,
a
and
I'll
also
open
the
the
chat
here.
B
So
let's
see,
YouTube
live
stream,
don't
tattoo.
So
we
have
a
question
from
James
Kemp.
Don't
the
two
sides
need
to
agree
on
a
data
schema?
Yes,
you're,
absolutely
correct,
in
which
a
data
schema
needs
to
be
the
same.
That's
why
there
are
fundamental
limitations
as
to
like
what
sort
of
like
interoperability
based
transaction.
B
You
could
sort
of
get
away
with,
so
if
in
the
case
of
which
they
don't
agree
on
a
data
schema,
for
example,
an
R3
quota
and
fabric,
you
basically
need
to
do
like
more
sort
of
groundwork
on
each
layer
of
a
ledger
one.
So
there's
like
we
could
transact
the
fabric
to
fabric
because
they
have
the
exact
same
data
schema,
but
in
the
case
of
Weaver,
when
you
have
like
R3,
Corda
and
Basu
R3,
Corda
and
fabric,
you
know
transacting
with
each
with
each
other.
B
There
are
specific,
like
libraries
and
additional
code
in
order
to
make
that
transaction
happen,
so
there's
a
sort
of
like
if
there
are
differences
you
need
a
sort
of
like
compromise
in
the
middle.
You
need
to
make
that
sort
of
shared
data
schema
between
the
two
networks
and
make
them
work
together.
Let's
see
another,
we
have
a
question
from
YouTube.
Could
I
use
one
chain
as
a
bridge
between
between
an
evm
client
and
cardano
mainnet?
If
there
is?
If,
yes,
is
there
a
documentation
how
to
implement
that
so
anon?
B
On
YouTube,
so
this
is
not
a
bridge.
This
is
an
atomic
cross
chain
swap
and
that's
a
topic.
Crossing
swaps
are
fundamentally
different
than
a
bridge
they're.
They
are
an
alternative
interoperability
mechanism,
so
technically
I
don't
have
context
as
to
whether
you
could
use
land
chain
as
a
bridge
for
evm
chain
and
cardano
mainnet.
If
you're
asking
whether
we
could
utilize
Wan
chain
to
do
a
cross
chain
swap
functionality
between
evm
and
cardano.
B
So
in
that
case
like
that
functionality
would
all
have
to
be
built
out
and
no
no
documentation
currently
exists.
For
that,
let's
see,
Daniel
Sego
has
a
question.
Is
there
a
way
to
execute
business
logic
in
blockchain
interoperability
off
chain
between
the
two
blockchains
in
a
trustless
way,
so
exchanging
one
token
or
several
different
types,
an
amount
of
token
on
another
chain,
with
some
off-chain
program,
logic,
so
off
chain
between
two
different
blockchains?
B
So
and
in
this
case,
like
the
way
that
Atomic
cross
chain
swaps
work
is
that
every
individual
layer,
one
will
have
like
a
like
a
block.
They'll
append,
like
sort
of
what
the
result
of
that
sort
of
transaction
was
on
so
they're
their
own,
like
on
sort
of
their
own
blockchain.
So
technically,
the
hyper
Ledger
Weaver
part
like
the
the
arbitrary
communication
between
different
layer
ones,
the
individual
components
that
talk
to
each
other.
B
So
if
we
wanted
to
add
land
chain,
for
example,
we
need
to
add
additional
libraries
and
and
stuff
in
the
SDK
so
that
we
could
have
one
chain
compatible
with
the
hyper
electric
Weaver
framework,
but
like
a
lot
of
this
is
technically
done
like
outside
the
blockchain
you're.
Only
at
like
you're
only
like
retroactively
updating
the
individual
layer,
one
blockchain
sort
of
like
after
the
swap
has
occurred.
If
that
makes
sense,
let's
see
GQ
has
a
question.
B
B
Hello:
okay!
Well,
in
that
case,
I'll
just
go
back
to
gq's
question,
so
hdlc
only
does
swap
not
transfer
between
the
two
blockchains,
so
in
in
this
case,
like
a
hash
time,
lock,
contract
I
mean
not
necessarily
so
you
can
use.
You
can
use
a
hash
time
luck
contract
to
to
basically
do
a
transfer
in
which,
like
a
swap,
is
basically
you're
exchanging
one
asset
for
another,
whereas
a
hash
time
like
contract.
B
It's
just
a
flavor
of
smart
contract,
in
which
you
know
the
two
conditions
are
time
as
well
as
like
the
cryptographic
passphrase.
Basically,
so
you
could
have
the
hclc
can
do
things,
one
way
in
which
you
know
if
I
as
Alice
just
wanted
to
send
100
tokens
to
Bob
or
a
single
nft
to
Bob,
but
Bob
gives
nothing
in
return.
All
Bob
needs
to
do
is,
like
you
know,
once
Alice
disperses,
you
know
the
individual.
You
know
like
like
the
pre-image,
and
you
know
Bob.
B
Is
that
the
correct
time
he
can
unlock
that
100
Bitcoin
or
one
nft
and
claim
it,
but
there
is
no.
There
is
no
sort
of
like
assertion
that
an
hdlc
can
only
do
a
swap
in
which
Bob
has
to
give
something
back
so
like
hclcs
can
go
one
way.
If
that
makes
sense,
do
we
have
any
additional
questions
at
this
time.
B
A
Well,
just
thank
you
Francis
and
thank
you
for
everybody
who
dialed
in
both
on
zoom
and
on
YouTube,
and
thanks
for
all
your
questions.
We,
if
you
have
additional
questions,
you
know
we
we,
you
know
it's
an
open
source.
Community
we
would
love
to.
You
know,
continue
the
discussion,
please
feel
free
to
join
us
on
hyperledger's,
Discord
server
or
our
mailing
list,
or
our
project
calls.
You
know
this
is
not
the
only
opportunity
to
talk
to
people
about
what's
going
on
with
interoperability
in
the
community.
A
So
hopefully
this
is
the
start
of
many
more
conversations.
I
see
here
question
here,
but
will
the
recording
be
available
on
YouTube,
yes,
I
hear,
let
me
send
the
link.
What
I'll
also
do
is
I'll
send
these
links
over
an
email
to
everybody
who
signed
up
so
Francis.
If
you
have
those
slides,
if
you
send
them
to
me,
I'll
send
those
out
to
everybody
who
and
I'll
send
the
slides
and
the
YouTube
recording
to
everybody
who
signed
up.