►
Description
A Central Bank Digital Currency (CBDC) is a new form of digital money with a central bank liability. The goal is to retain all the benefits of central bank money (especially no default risk) and pushing beyond this by improving on multiple dimensions: Settlement Efficiency, Robustness, Privacy, Compliance, Accessibility, and Programmability to name a few.
This workshop is run by blockchain engineers at Banque de France and IBM. The event provides a technical presentation and feedback on the Banque de France Venus CBDC experiment and how Hyperledger Fabric addresses many of the requirements for CBDC use cases. In this talk, we will show how Hyperledger Technologies helped build a CBDC, how it was used to orchestrate interoperability with HTLC, and will offer a deep-dive and hands-on session on the Hyperledger Fabric Token SDK lab.
More about Hyperledger Fabric and the fabric-token-sdk lab is at:
https://github.com/hyperledger/fabric
https://github.com/hyperledger-labs/fabric-token-sdk
And for any questions about the workshop, you can ask in the #fabric-token-sdk channel on Hyperledger's Discord server at: https://discord.com/channels/905194001349627914/945691840110272522
Information about how to join Hyperledger's Discord server is at:
https://chat.hyperledger.org/
----
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
Discord: https://discord.gg/rVCn4j7UFd
Case Studies: https://www.hyperledger.org/learn/case-studies
Training & Certification: https://www.hyperledger.org/learn/training
Tutorials: https://www.hyperledger.org/use/tutorials
Webinars: https://www.hyperledger.org/learn/webinars
Events: https://www.hyperledger.org/events
Vendor Directory: https://www.hyperledger.org/use/vendor-directory
Subscribe to the Hyperledger Newsletter: https://www.hyperledger.org/newsletter
Follow-us on Twitter @Hyperledger
Learn about Hyperledger Membership: https://www.hyperledger.org/about/join
#Hyperledger #Blockchain
License
Creative Commons Attribution license (reuse allowed)
B
C
But
we
also
have
people
from
Bank
of
France
team
that
will
present
the
experimentation
we
did
around
Venus
and
they
will
give
more
information
on
this.
With
no
further
delays.
I
will
hand
over
to
the
rest
of
the
people
to
introduce
themselves
and
then
to
Clement
and
quarantine
to
start
off
with
the
central
Bangladesh
or
currency
definition,
requirements
and
the
context
of
Venus
Project.
D
Technical
staff,
member
at
IBM
researcher,
Zurich,
working
with
with
aliens
of
decentralized
trust.
Maybe
some
of
you
knew
me
also
because
I've
been
for
for
three
years
and
in
the
TSC,
the
technical
Committee
of
hyperledger,
the
average
project
was
really
a
lot
of
fun
being
there
and
I'm
one
of
the,
as
you
know,
I'm
one
of
the
architects
of
a
hyper
natural
fabric
as
well
and
the
token
the
token
SDK
that
we
will
see
who
we
will
see
today.
Thank
you,
foreign.
F
F
Okay:
okay
thanks,
so
we
will
start
this
presentation
by
key
definitions
and
Concepts
about
money
and
synthesis,
and
we
will
give
you
some
some
background
on
about
the
France
experiments.
Then
we
will
present
yours
GLT
that
we
used
on
many
of
our
experience
and
after
that
we
will
give
you
a
feedback
on
the
Venus
experiment
that
was
conducted
in
a
partnership
with
a
box
100
example
and
government
sacks
in
2022..
G
So
Crema
and
myself
we
are
part
of
the
BDF
blockchain
Team,
so
it's
a
team
of
nine
experts.
So
we
are
only
two
of
us
today,
but
we
are
nine.
We
various
skills
and
this
team
was
created
in
2021
to
assemble
most
blockchain
skills
and
capabilities
to
support
initiatives
and
around
blockchain
and
GLT
internally.
G
Because
we
know
we
all
know
I
think
on
blockchain.
Project
is
not
only
here,
only
a
little
option
that
we
have
to
build
so
to
better
understand
and
introduce
cbdc.
Let's
try
to
have
a
more
global
vision
about
the
different
forms
of
money
currently
and
their
purpose,
at
least
on
Euro
system
framework.
G
So
it's
a
it's
a
quick
introduction
just
to
yeah
to
to
have
a
better
visualization
for
for
for
for
everyone,
but
you
we
have
three
different
big
kind
of
actors,
so
we
have
the
central
bank
that
is
issuing
and
guaranteeing
the
two
different
forms
of
currency
depending
on
the
on
the
actors.
So
we
have
the
fiduciary
money,
that
is,
the
cash
the
coins
and
bills
that
we
are
using
for
for
for
payments.
G
That
is
a
physical
physical
form
of
this
money,
but
we
also
have
a
scriptural
money,
that
is
a
commercial
Banks
account
with
the
central
bank
for
inter-based
sentiments
and
so,
depending
on
the
on
the
reserve
that
the
central
banks
have
they
can
issue
another
form
of
commercial
money.
This
time.
That
is
the
another
form
of
scripture
money.
G
But
it's
customer
accounts
that
customers
at
the
at
the
commercial
at
the
Commercial
Bank
and
it's
the
digital
form
that
we
know
in
our
bank
account
correctly
and
the
convertibility
is
assured
between
between
all
those
kind
of
money
of
different
forms
of
money
which
is
makes
the
system
works
for,
for
instance,
one
bill
of
one
Euro
is
equivalent
to
one
Euro
in
a
bank
account.
So
it's.
G
G
It
will
be
a
digital
version
of
banknotes
that
currently
are
only
physical
with
the
aim
to
be
more
efficient
and
to
serve
as
Alternatives
with
the
declination
of
the
use
of
the
cache,
because
currently
we
don't
really
have
a
digital
version
for
retail
central
bank
money.
We
have
one
version
for
the
commercial
bank
money
with
bank
accounts,
but
not
for
the
money
that
is
issued
by
Central
Bank.
G
G
They
are
currently
providing
with
the
aim
of
adapting
them
to
this
new
digital
age
and
the
possible
Associated
development
of
the
token,
as
Finance,
by
offering
a
safest
and
liquid
settlement
assets,
technological
progress
to
enhance
market
efficiency.
Why
assuring
entering
sorry
their
stability,
so
free
objective,
different
objectives
that
can?
That
would
be
the
goal,
I
would
say
of
those
kind
of
Technologies,
so,
first
of
all
the
monetary
sovereignty.
That
is
an
important
topic
today.
F
The
second
objective
was
to
identify
the
benefits
of
introducing
CDC
from
the
Quran
ecosystem
and
identify
to
our
CDC
by
the
First
Financial
Innovation,
and,
to
achieve
that,
we
are
analyzed
the
result
of
the
experiments.
We
were
regarded
with
the
existing
ecosystem
and
we
are
compared
a
performance,
efficiency,
security
and
possible
productivity
gains.
F
And
to
personalize
the
objective
is
called
for
application:
it
was
to
conduct
a
real
life
experiments
with
the
financial
industry
and
within
the
existing
legal
framework,
and
this
is
called
for
application,
received
a
great
success
with
a
strong
response
from
the
ecosystem.
We
received
more
than
50
application
feelings.
We
were
abroad,
business
and
Technical
coverage
from
a
business
point
of
view.
We
received
the
responses
from
a
wide
variety
of
actors
such
as
Banks
and
fintechs
from
around
the
world,
and
we
were
Diversified
proposals
on.
G
G
G
G
We
have
several
different
shutters
for
for
this
platform,
for
example
the
simplification
and
automation
of
the
different
processes,
Financial
processes
that
I
mentioned
just
previously,
with
reduction
of
in-processing
times,
compared
to
what
we
currently
have
in
Legacy
systems
counterparty
risk
reduction
with
atomic
transactions
thanks
to
the
to
the
DHE
Technologies.
But
but
also
the
the
use
of
Central
Bank
currency
multi-currency
is
possible
on
the
platform,
but
also
across
all
the
payments,
and
the
platform
was
built
in
eco-friendly
way.
G
All
the
technical
part,
we
it's
a
fully
decentralized
solution.
I'm
gonna,
I'm
gonna
show
why,
after
afterwards,
but
it's
in
the
blockchain
philosophy,
we
have
confidential
and
Anonymous
transactions,
but
that
can
be
also
auditable
thanks
to
specific
technologies
that
I
think
aliens
and
kyota
will
will
speak
more
deeply.
After
afterwards.
G
So
let
me
present
you
more
simplified
technical
stack
about
about
the
application
for
to
to
have
a
better
visualization
of
it.
So
the
first
layer
is
the
business
features.
So
it's
in
a
user
interface
that
is
built
in
angular,
so
it's
a
PDF
interface
Pro
proposal.
But
finally,
this
one
can
be
modified
adapted
to
to
specific
needs
for
for
the
participants,
for
example,
or
integrated
into
their
own
system.
G
We
also
have
the
the
FSC
FTS
stack,
which
will
be
presenting
more
in
details
later
on
in
this
Workshop,
to
allow
us
to
make
option
interactions
in
the
context
of
the
dr3s
between
participants,
while
having
a
token
implementation
with
privacy
and
auditability
thanks
to
zero
knowledge,
asset
transfer,
the
cats
implementation
and
we're
also
using
the
HLF
SDK
group
to
interact
with
the
protocol
layer.
Sorry
that
is
iPad
fabric
using
idemix,
which
provides
a
strong
authentication
as
well
I
price,
a
privacy
price
having
features
such
as
anonymity
and
earning
ability.
G
We
also
using
a
formal
private
data
to
allow
sharing
or
private
but
verified
informations
between
different
parties.
We
are
using
raft
as
consensus
for
the
ordering
service
ports
and
cards.
Db
has
a
worsted
for
level
as
Horses,
sorry
for
Rich
credits
and,
finally,
all
those
things
are
deployed
on
on
cloud
infrastructures
in
Docker
containers
that
are
orchestrated
via
document.
G
So,
as
I
already
mentioned,
it
was
it's
a
service
oriented
architecture
with
a
multi-code
setup
that
is
possible.
We've
done
some
performance
testing,
but
it's
more
focused
on
HLF,
not
gl3s
as
well,
but
on
HLF,
something
it's
up
to
2K
GPS.
So
pretty
good
good
number,
at
least
for
the
protocol
layer
part,
and
we
have
interoperability
so
to
name
few
with
traditional
platform,
so
Target
Two
Securities,
that
is
a
European
Legacy
system
and
that's
offering
centralized
delivery,
Business
Payment
settlement
having
cash
and
securities
on
the
same.
F
F
F
B
H
G
Let's
see
so
sorry
for
the
for
the
intervention.
I
have
some
issue
with
my
live
voice.
Currently,
it's
maybe
to
try
to
to
speak
loud
I'm
for
it,
in
goodness,
in
the
United
States,
financially
end
of
the
presentation.
But
so
let
me
quickly
go
through
the
network
topology
that
we
use
for
various
experimentation.
G
So
we
retrieved
the
different
participants
that
clemma
mentioned
just
before,
and
so
we
have
different
participant
types
that
are
possible
in
the
air
freeze
Network.
So
we
have
the
two
central
banks,
some
difference
and
BCL
the
two
cases
that
are
blockchain
participants
on
the
network,
so
the
host
the
blockchain
node
of
the
network
and
therefore
has
access
to
the
religion.
So
if
we
come
back
to
the
technical
stack
that
represented
previously,
they
finally
are
hosting
every
layers
of
the
stack.
Obviously
we
have
eib
so
the
European
Investment
Bank.
That
is
a
direct
participants.
G
G
So,
as
I
already
mentioned,
we
had
a
raft
implementation
for
the
ordering
service.
We
have
a
free,
Aurora,
node
or
nodes
distributed
on
the
network
that
are
not
represented
here,
because
it's
more
technical
notes
for
making
a
high
pressure
fabric
working,
but
it
was
three
different
instances
that
those
that
we
are
seeing
currently
and
for
the
hosting
parts
for
the
address
df3s.
At
this
we
have
different
modes.
G
All
the
participants
stack
on
the
on
its
own
Cloud
to
the
independent
testing
of
the
stack
of
the
different
participants,
for
instance,
government
tax,
who
could
Ulster
its
own
on
node
and
interact
with
the
others
that
could
be
asked
somewhere
else
so
and
just
to
to
make
some
context
here
for
various
experiments.
We
use
military
instances
configurations,
but
it
was
almost
on
on
mono
Cloud
on
with
a
model
called
hosting
at
one
difference,
even
though
it's
something
that
we
already
did,
the
military
in
other
experimentations.
F
I'm
going
to
explain
the
general
hdlc
mechanism
here
we
have
a
two
distant
blockchain
Networks,
so
security
is
Network
on
the
left
called
the
network
one
and
the
cache
Network
on
the
right
called
the
network.
Cash
and
securities
stay
on
the
respective
Network.
That
means
the
cash
or
List
athletes
on
the
cash
Network
and
the
Securities
early
circulates
on
the
Securities
Network,
and
that's
not
like
a
bridge,
for
example,
which
would
allow
tokens
to
go
from
a
one
block
channel
to
another.
F
F
The
principle
of
the
hdlc
is
that
Alice,
Lots
or
Securities
in
a
smart
contract
using
garage,
smart
contract
with
that
same
hash
and
then
Alice
claims
the
cash
are
using.
The
Supreme
edge
of
the
ash,
which
relates
at
the
same
time,
is
a
green
Edge
and
allows
both
to
claim
the
Securities.
But
that's
in
in
details
the
different
steps
that
we
have
here.
F
So
we
start
with
A
Step
Zero,
which
is
the
option
agreement
between
Alice
and
Bob
to
to
define
the
terms
of
the
GB
and
before
our
initiating
the
sjs
process,
I
recent
board.
So
this
is
a
master
agree
on
the
amounts
of
Securities
and
cash
to
exchange
and
also
on
overall
parameters.
I
will
introduce
to
you
in
a
few
seconds,
such
as
the
timers
after
step.
One
Alice
generates
a
secret
and
then
she
she
aches
it.
F
A
great
amount
of
Securities
until
is
enriched
and
a
bubble
checks
this
and
if
he
arrives
with
the
conditions
set
by
the
smart
contracts.
Designer
goes
to
step
three
step.
Three
above
locks
CDC
on
the
network,
two
with
with
the
same
Ash
than
the
ice
and
the
fourth
diet
and
Ash
when
he
audited
RC
smart
contract.
F
In
this
example,
we
use
a
t
and
2T
from
respectively
the
cash
timeout
and
the
Securities
timeout,
but
overall
values
could
be
used.
The
important
ID
here
is
that
cache
timeout
must
be
strictly
less
than
a
Securities
timeout
in
such
a
way
as
to
always
let
enough
time
for
Bob
to
claim
Securities.
Once
cash
has
been
claimed
by
Alice
at
step,
four
in
the
same
way
as
Bob
and
his
audits
about
htmc
smart
contracts
before
moving
forward,
and
if
she
agrees
with
the
term
of
the
smart
contract,
she
then
goes
to
step
five
at
step.
F
Five
Alice
claims
broad
CDC,
using
a
sequence,
s
and
B4
barrier.t
expires
and
while
claiming
cbdc
at
least
reveals
or
Secrets.
At
the
same
time,
and
of
course,
the
smart
contract
checks
that
hashing,
the
secrets
results
before
transferring
the
cash
grants
and
the
claim
of
of
the
CDC
and
the
sharing
of
the
secrets
are
done
in
a
single
Atomic
transaction.
F
So
that
means
that
the
Aries
cannot
receive
as
a
cash
if
the
secret
is
not
rebuilt
and,
conversely,
the
secret
cannot
be
revealed
if
Alice
does
not
get
the
CDC.
So
this
is
this
all
under
finger
logic
that
makes
it
possible
to
deliver
cash
and
securities
in
turn
with
a
delay,
because
Bob
has
the
guarantee
that
it
will
be
able
to
claim
the
Securities
by
using
as
a
published
sequence,
and
the
last
step
is
Step.
F
F
F
Without
a
trusted
property,
it
uses
a
cryptographic
process
that
links
private
data
as
a
secret
to
a
public
data,
so
Ash
as
the
assets
are
locked
with
the
Ash
and
unlocked
River.
The
secrets
and
the
recipient
can
unlock
and
unlock
the
asset
due
to
him
on
the
condition
of
providing
the
secrets
weaving
a
predetermined
time
frame.
F
F
F
F
So
there
is
no
caution:
communication
between
the
custodians
of
the
Bayer
and
the
seller,
so,
as
you
can
see
in
the
diagram
at
the
top
right,
there
are
two
communication
channels.
The
first
one
is
between
the
buyer,
security
custodian
and
the
biosity
custodial,
which
above
represent
the
buyer
and
the
second
Communication
channel
is
Between
the
seller,
security
custodian
and
the
sellers
CDC
custodian,
which
both
represent
the
seller.
F
We
have
identified
some
some
clear
feedback:
hdrc.
The
Costless
protocol,
so
there
is
knowledge
from,
and
that
implies
a
high
level
of
security
exchange,
allows
conditional
dividends.
So
in
fact,
SJC
does
not
achieve
atomicity
because
it
is
on
an
interactive
process
consisting
of
a
combination,
a
sense
of
option
and
unseen
operations
and,
depending
on
the
results,
different
states
can
be
obtained
at
the
end.
F
One
of
the
important
points
that
I
have
already
mentioned
before
is
that
there
is
an
atomicity
of
a
cash
claim
and
a
secret
sharing
operations
which
are
done
in
a
single
transaction
with
all
of
all
other
finger
logic,
and
if
resistor
two
operations
are
not
done
in
the
same
transaction,
HTC
HDFC
cannot
work.
I
would
say
that.
F
There
are
free
messages
that
we
call
on
message,
one
message:
two
and
the
message:
three
to
emphasize
their
order
of
execution,
and
these
messages
are
sent
automatically
between
the
two
directives.
So
there
is
no
operator
Beyond
them
now,
let's
see
the
the
content
and
the
role
of
each
of
these
messages.
F
After
adding
a
locked,
the
Securities
and
the
Securities
agility,
the
sellers,
Securities
custodiano
sends
the
message
one
to
the
sellers,
CDC
custodian.
In
order
to
share
the
settlement
section
with
the
secrets
and
the
letter,
the
seller
of
the
cvdc
custodians
will
be
able
to
claim
the
cache.
Using
on
that
secrets,
we
received
from
a
message
one.
F
The
secret,
which
is
public
now
and
it
shares
it
to
the
buyers,
Securities
custodian,
Vayas
and
necessary,
and
after
receiving
the
message
free,
the
buyer,
Securities
claims
or
Securities
using
subsequence
with
no
expose.
You
were
some
some
highlights.
We
have
identified
this
setup
is
efficient,
but
it
requires
the
implementation
of
a
several
contingency
procedures
in
order
to
to
manage
some
other
stuffs.
F
But
there
are
some
operational
risks
which
are
not
the
same
for
the
buyer
and
the
seller.
The
risk
for
processary
is
a
leak
of
the
secret
after
our
Securities
have
been
locked
and
before
cash
has
been
locked,
and
in
that
case
the
buyer
will
be
able
to
claim
the
Securities
without
having
to
to
lock
the
CDC.
F
Let's
try
to
to
conclude
with,
with
the
main
highlights,
Nissans
learned
from
Avengers
experiment,
but
overall
experiments
too
blockchain
and
Agility
technologies
have
arranged
sufficient
maturity
to
become
serious
candidates
for
Android
marketing
associations,
circulation,
ownership,
control
and
supervision
can
all
be
a
sexual
securely
supported
applications.
Networks.
G
Potential
of
post-trade
Capital
Market
settlement
operations
in
cbdc
for
French
Sovereign
depth
securities,
and
for
this
experimentation
there
were
there
were
both
the
currency
and
the
Securities
and
the
same
platform
that
was
there
for
yes
and
for
HD
HSBC.
So,
in
addition
up
to
the
insurance
and
distribution
of
the
cbdc,
the
idea
was
to
experiment
bonds
subscription
subscription,
sorry
in
primary
and
secondary
markets,
including
company
payments
and
the
execution
of
cross-border
and
cross-network
payments.
G
So
in
this
experiment,
several
networks
with
several
Technologies
as
I've,
been
used
so
iPad,
Fabric
and
and
yeah
free
code
interoperated
through
hyperledger
Weaver,
that
is
now
being
included
into
hyperledger
cacti
and
maybe
just
to
open
a
bit
about
that.
The
fact
that
all
the
experiments
that
we
accumulated
and
the
Earth
was
development
and
and
the
things
that
we've
done
for
evidence
experiments
are
being
currently
invested
in
the
pilot
regime.
G
That
is
a
the
text
with
the
main
aim
is
to
have
a
temporary
framework
that
should
provide
favorable
context
for
the
for
the
user
production
for
financial
securities
in
the
entire
Banking
contexts.
And
so
this
is
the
opening
point
for
central
banks
for
the
settlement
asset
that
that
will
be
used
in
in
this.
In
this
context,
I
will
copy
paste
all
the
all
the
links
mentioned
in
the
chats
folders
that
are
interesting
to
to
dig
a
bit
more
about
what
we
presented
still
no
report
for
for
the
Venus
experiment
so
and
for
the
others.
G
G
C
Nice
overview
of
Clement
and
current
team
I'm
gonna
give
on
what
Central
Bank
digital
currencies
are.
The
exact
scope
and
deliveries
on
the
Venus
Project
I'm
gonna
give
an
overview
of
the
hyperledger
Technologies
relevance
into
the
Central
Bank
digital
currency
topic,
starting
off
with
a
very
high
level
architecture
of
the
typical
Central
Bank
digital
currency
and
system.
C
We
see
tier
two
are
referring
to
a
retail
Central,
Bank
digital
currency,
facilitating
exchanges
of
cash
between
individuals
or
corporations.
Just
like
we
do
today
with
our
banknotes
that
we
have
on
our
wallet
and
that
we
use
to
pay
and
then,
on
the
last
end,
we
do
have
the
consumer
that
would
order
the
payment
service,
provided
that
would
interact
through
apis
to
the
retail
cbdc
Network,
to
offer
a
service
to
other
consumers,
individuals
that
would
itself
need
to
interact
and
interoperate
with
a
wholesale
cbdc
Network.
C
Of
course,
a
lot
of
requirements
I
already
mentioned
not
explicitly,
but
I
mentioned
interoperation,
for
example,
being
important.
One
interoperation
between
two
different
Central
Bank
digital
currency
systems,
different
partitions
of
the
same
Central
advantage
of
currency
system,
even
but
also
interpretation
between
a
central
bank,
digital
currency
system
and
Legacy
systems.
So
this
is
an
aspect
that
we
know
for
sure
will
be
important
and
because
of
the
variety
of
the
of
the
importance
that
a
system
would
be
compliant
to
regulation
and
to
some
extent,
regulation
differing
from
a
country
to
Country.
C
C
Privacy
of
the
payments
involved,
especially
if
we
are
talking
about
a
system
that
we
need
to
transparently
validate
transactions
that
appear
in
it,
such
that
every
participant
in
it
can
verify
that
this
transaction
was
indeed
honoring
the
rules
of
that
asset
management
system,
but
at
the
same
time,
privacy
needs
to
be
combined
with
accountability,
namely
participants
of
the
system
should
not
be
able
to
repudiate
their
participation
in
a
certain
transaction.
So
strong
identity
management
already
becomes
a
clear
need
in
this.
C
Even
in
the
event,
if
some
nodes
in
the
system
get
com
get
get
a
fail
like
crash,
but
also
in
the
case
where
nodes
in
the
system,
some
notes
on
the
system
come
from,
get
compromised
and
introduce
arbitrarily
messages
into
the
system
trying
to
mess
up,
possibly
with
the
systems
operation.
So
resilience
for
critical
infrastructure
of
this
sort
is
an
important,
and
this
is
where
distributed.
Ledger
technology
could
bring
a
strong
value.
C
For
the
wholesale
Central
Bank
digital
currency
was
already
mentioned
before,
performance
is
not
so
challenging
to
address,
but
when
it
goes
to
this
retail
Central
Bank
digital
currency.
This,
because
it
becomes
of
critical
importance
and
quite
challenging
to
address,
especially
with
all
these
other
requirements
link
address
at
the
same
time,
and
we
want
to
emphasize
that
it
makes
sense.
C
Also
they
separate
the
set
of
requirements
on
the
two
letters,
the
governance
level,
which
says
who
should
be
making
decisions
into
to
to
to
upgrade
the
system,
changing
the
rules,
the
asset
management
system.
So,
for
example,
some
thresholds
of
cars
at
that
particular
entity
in
the
system
should
own
or
upper
bound
of
of
these
sorts,
so
who
should
be
authorizing
the
issuance
of
new
money
to
the
system
and
so
on
and
so
forth.
C
So
Governors
have
their
own
subsets
of
requirements
to
address
again
around
compliance,
privacy
and
and
accountability,
but
also
resilience.
But
it's
also.
Another
level
is
when
it
comes
to
decisions
that
have
already
been
taken
to
be
enforced.
Then
it
comes
to
the
execution
side
where
again
we
have
distributed
setting.
That
brings
a
lot
of
advantages,
as
we
will
discuss
later
and
where
again,
we
will
need
the
system
to
support
the
transaction
processing
with
Hydro
base
of
resilience
and
to
meet
all
these
requirements
is
not
an
easy
thing.
C
We
know
from
cryptography
and
security.
There
are
ways
that
one
could
combine.
Privacy
and
transparency,
for
example,
we
have
Primitives
cryptographic
element
is
like
zero
knowledge,
proofs
or
secure
most
part
computation
that
could
be
used,
but
these
come
with
certain
overheads,
computation
overheads
and
they
need
to
be
treated
with
care
so
to
meet
to
to
have
a
system
that
would
accommodate
all
these
requirements
in
combination.
It
makes
sense
to
do
a
full
Technology
stock
investigation.
C
Libraries
like
and
ones
that
are
evident
that
we
need
here
are
the
ones
around
identity
management
and
the
ones
around
Asset
Management,
like
token
exchange
all
the
way
to
incorporating
certain
capabilities
into
the
platform
level
that
in
this
case,
it
is
represented
by
a
distributed
Ledger
technology,
then
in
particular
hyperledger
fabric.
Ideally,
one
would
also
need
to
engage
with
fans
dedicated
infrastructure,
optimized
Hardware,
to
speed
things
up,
but
the
important
point
is
is
that
Mont
could
not
possibly
address
all
this
in
a
practical
system
from
a
performance
scalability
perspective.
C
So
I
our
speakers
before
quarantine,
employment
already
mentioned
the
industry
confirmations
about
the
relevance
of
distributed
Ledger
technology
into
Central,
Bank
digital
currency.
I'll
summarize
it
here
so
this
distributed.
Ledger
technology
brings
value
in
business
networks
in
three
ways,
through
the
distribution
of
trust,
building,
trust
essentially
across
a
set
of
participants
that
are
not
necessarily
mutually
trusting
each
other
transparency
and
Automation.
C
All
the
way
are
resulting
into
much
shorter
trading
side
trade
to
settlement
cycle
to
essentially
zero
days,
within
the
same
day,
at
least
compared
to
today,
that
it
would
take
at
least
a
couple
of
days
to
take
place.
Last
but
not
least
because
of
again
of
the
transparency
that
it
brings
into
the
picture
and
the
fact
that
the
single
Ledger
is
acting
as
a
source
of
Truth
traceability,
it
was
also
be
enabled,
and
overall,
reconciliation
would
be
better.
Optimized.
C
So
that's
in
short,
and
these
are
an
overview
of
hyperledger
technologies
that
can
be
brought
together
in
order
to
meet
the
set
of
requirements
that
were
mentioned
before.
Of
course,
I
mentioned
the
identity
management
and
there
we
have
a
strong
Representatives
on
hyperledger,
Ursa
and
Iris
and
Indie
projects.
We
have
interoperability
Frameworks.
We
have
a
cacti,
a
hyperledger
project
that.
B
C
We
will
focus
our
discussion
on
these
two
parts:
hyperledger
fabric,
token,
SDK
and
and
smart
client,
as
well
as
a
hyperledger
fabric,
I'm
not
going
to
dive
deep
into
the
token
SDK,
because
Angelo
encounter
have
lots
to
say
about
this.
I'm
also
I'm,
only
gonna
emphasize
on
a
few
distinct
characteristics
of
this
components
that
were
made
that
technology
relevant
to
the
dl3s
platform.
That
was
mentioned
also
before
the
main
characteristic
here
and
you
know,
Asset
Management
has
been
very
long
investigated
into
the
decentralized
trust
community,
blockchain
community
and
it's
quite
a
straightforward.
C
What
one
is
to
check
in
a
given
transaction
that
moves
an
asset
from
one
party
to
the
other,
especially
trivia,
trivial,
like
conceptually,
not
in
practice?
I
guess
I
wanted
to
implement.
It
is
no
trivial,
but
the
idea
is
that
one
is
to
check
whether
the
owner
or
the
current
registered
owner
of
the
asset
is
the
one
authorizing
the
transfer
and
that's
during
the
transfer.
There
is
no
new
money
created
if
I
own
one
US
dollar
I
can
spend
at
most
one
US
dollar.
C
I
cannot
spend
more,
and
this
is
essentially
being
converted
by
the
community
into
a
privacy
preserving
setting
where
everything
is
concealed,
but
everyone
is
able
to
check
that
at
least
it's
the
owner
of
the
asset
that
has
been
authorizing
the
transfer
of
its
and
that
the
value
the
balance
property,
essentially
no
new
money
has
been
creating
upon
transaction,
is
being
preserved
in
the
Enterprise
setting,
which
is
again
compatible
to
what
we
mentioned.
The
Central
Bank
wholesale
Central
Bank
digital
currency
would
look
for.
C
Privacy,
knowledge,
support,
differentiators,
but
also
that
offer
some
supports
for
interoperability.
Hash
time
locked
protocol
that
was
mentioned
before
is
something
that
there
are
hooks
into
the
answers
that
it
can
interact
with
another
system
supporting
that
protocol,
but
two
important
things
we
also
need
to
mention
here.
C
Third
thing,
equally
important
is
that
it
is
not
just
a
system
that
that
we
built
a
prototype
that
was
built
and
was
put
under
hyperledger
lab,
but
it
is
also
has
the
protocol
itself
have
been
reviewed
by
the
scientific
Community,
and
it's
it's
out
there
in
detail.
The
cryptographic
protocol
can
be
reviewed
and
the
technology
has
already
incorporated
into
mature
Central
Bank
digital
currency
experimentation,
including
the
dl3s
and
subsequently,
to
Venice
projects
that
that
were
mentioned
before.
C
So,
just
a
few
words
just
to
conclude
on
the
relevance
of
hyperledger
fabric
for
Central
Bank
digital
currencies.
Again,
one
question
would
be
okay.
Why
would
you
use
a
permission
DLT
for
Central
Bank,
digital
currencies?
Our
view
there
is
depends
on
the
governance
mechanisms
that
would
be
desired
in
this
setting.
C
What
happens
if
there
is
a
bug
into
my
smart
contract
that
has
been
developed
and
some
money
have
already
been
transferred
by
a
Target
that
has
leveraged
that
bag,
so
another
address
that
nobody
can
get
access
to
or
cannot
easily
Blacklist.
So
the
governance
side
is
important.
If
you
remember
in
the
past,
this
has
happened
like
2016,
if
I'm
not
mistaken
or
a
year
later,
and
it
led
to
our
forking
the
public
Ledger
system
that
was
there.
C
So
governance
is
an
important
reason
and
control
on
the,
depending
on
the
on
the
on
the
preferences
or
the
specifications
of
them
level
of
control
that
the
central
bank
and
the
Commercial
Bank
should
have
inside
the
system,
and
appropriate
technology
would
make
sense
to
be
used.
So
hyperledger
fabric
is
able
to
leverage
to
how
it
comes
with
a
very
modular
policy
framework,
allowing
policies
to
be
said
for
different
levels
of
the
system.
C
So
it
has
a
very
Advanced
policy
framework
addressing
a
lot.
This
Enterprise
need
for
specifying
authorization
of
different
parties.
In
there
we
also
have
modularity,
modular
and
Agility.
In
the
way,
the
system
has
been
architected
modularity
and
the
crypto
components
and
the
membership
components
allowing
an
easy,
smooth
transition
of
the
system
to
another
crypto
library
or
eventual
post
Quantum
question
Quantum,
safe
crypto
libraries
that
will
come
up
at
some
point
and
it
will
merge
at
some
point
in
time.
C
So
it
is
well
founded
on
multiple
aspects
in
multiple
ways,
and
this
is
to
talk
about
the
throughput
of
the
system,
and
actually
these
numbers
are
a
bit
outdated,
but
Byzantine
fault.
Tolerance
is
the
consensus
algorithm,
allowing
strong
resilience
to
faulty
notes,
notes
that
not
only
crash
but
can
also
become
assumed
compromise
exhibit
an
arbitrary
behavior
when
it
comes
to
processing
transactions.
So
this
is
definitely
a
desired
property
in
the
system
and
we
already
have
a
smart
PFT
included
into
Fabric
in
an
early
version
of
it.
C
C
Last
but
not
least,
I
mentioned
identity
being
the
needed
Foundation
of
a
secure
asset
management
system
and
in
particular,
identity
mechanism
that
would
allow
privacy
preservation
brush
with
accountability
property.
Strong
accountability
properties
in
place.
Hyperledger
has
been
very
active
in
that
space.
We've
seen
a
non-creens
protocol,
hyperledgeritis
Ursa.
Of
course,
the
projects
are
associated
to
that
and
we've
seen
a
lot
about
a
known
credit
specification
protocol
allowing
this
combination
of
privacy
and
accountability.
C
I
also
want
to
mention
the
centralized.
Identity
comes
with
strong
advantages
on
the
on
the
scalability
and
privacy
side
of
things.
Since
the
users
are
the
ones
owning
the
level
in
which
they
will
interact
with
their
environment,
share
information
with
their
environment.
There
is
no
Central
Authority
that
needs
to
get
access
to
all
the
information
about
the
user
and
leveraging
such
a
mechanism
collecting
that
with
asset
management
is
but
very,
very
much
relevant
in
that
context
and
identity.
C
D
Good
great
okay,
sometimes
it
goes.
It
goes
crazy,
all
right,
very
good.
So,
let's
move
to
this
other
face
of
the
this
other
session,
a
section
of
the
the
presentation
and
they
have
a
deep
dive
in
one
of
the
core
assets
that
was,
that
is
be
behind
all
the
the
the
efforts
that
have
been
you
you
have
been
described
described
so
far.
D
It's
the
fabric,
token
fabric
token
SDK,
I,
put
in
parenthesis
fabric,
because
it's
true
that
it
was
born
in
the
context
of
fabric,
but
over
time
it
evolved
to
become
something
that
is
agnostic
to
the
to
the
to
the
back
end
and
I
will
show
you
I
will
show
you.
Why?
So
for
this?
For
this
part,
for
this
section
for
this
session,
I
want
to
talk
about
the
Privacy
indeed
or
the
ability
path.
D
D
Locate
where
we
are
in
terms
of
the
stack
and
also
gives
you
give
you
some
other
highlights
to
better
position,
the
the
token
SDK.
So
this
is
what
early
presented
before
just
a
few
minutes
earlier,
so
we
are
there
at
the
the
do.
I
will
talk
about
the
centralizing,
the
regulated
tokens,
so
the
target
SDK
sits
in
that
at
the
Middle,
where
at
the
Middle,
where
components
so
from
it.
D
You
might
have
certain
compromises
in
certain
cases
or
you
want
to
have,
for
you
want
to
go
for
full
privacy,
no
matter
what
in
in
other,
in
other
cases.
So
for
us
this
was
was
an
important
point,
because
we
thought
okay,
we
need
to
be
flexible.
We
need
to
design
an
a
system,
a
stack,
an
asset
that
it's
flexible
enough
to
adjust
to
different
to
different
requirements
without
us
having
to
rewrite
the
application
continuously.
So
every
time
we
change
the
requirements,
we
have
to
rewrite
the
the
application.
D
No
matter
your
requirements
or
the
specific
requirements
for
the
use
case,
so
that's
reason
why
the
the
public
token
SDK
was
born.
We
wanted.
We
wanted
to
apply
all
the
cryptographic
we
wanted
to
Make
It
Real.
The
use
of
all
this
cryptographic
protocols
that
we
designed
over
over
the
years
in
a
in
a
in
a
software
stack
that
would
would
have
allowed
us
and
any
developer
to
create
quickly
token-based
applications
at.
D
Then
we
quickly
switched
the
two
to
an
an
infrastructure
that
would
can
allow
us
essentially
to
to
swap
fabric
to
change
fabric
with
other
with
other
dlts
or
even
centralized
system
by
by
all
means
it
doesn't
from
the
point
of
the
token
SDK
it
doesn't
really
it
doesn't
really
matter.
Let
me
let
me
go
again
earlier
the
game
already
a
heads
up
on
on
the
main
highlights
of
the
tokens.
D
Okay,
let
me
go,
let
me
going
in
through
through
them
and
give
some
some
also
motivations
on
on
some
of
these
points.
So
we
adopted
I
thought
we
decided
to
go
for
the
utxo
model
for
a
very
for
a
very
good
reason.
The
utxo
model
is
the
one
that
allows
gives
you
the
maximum
privacy
possible.
You
can
achieve
some
certain
certain
privacy
guarantees
in
the
account
model,
but
you
have
to
compromise
in
a
way
in
another.
There
are
compromises
to
be
made.
D
With
the
real
cache
with
your
banknotes
and
and
so
on,
the
token
SDK
takes
care
automatically
or
the
wallets
and
the
key
management,
so
you
can
use
hsms
to
store
keys
or
you
can
use
a
different
infrastructure
to
you
to
store
to
store
your
keys
or
you
can
just
turn
on
the
file
system
as
well.
But
the
token
SDK
takes
care
automatically
over
this
all
these
things.
You
don't
have
to
worry
about
that.
D
Actually,
after
this,
this
section,
we'll
talk
will
going
more
in
details
about
an
intervaliability
capabilities
that
we
embedded
in
the
in
in
the
token
SDK
all
right.
So
what
are
I
mean?
We
are
talking
about
tokens
you
take.
So
what's
a
token
for,
from
the
point
of
view
of
the
token
SDK,
it's
very
simple:
it's
the
following
triplet!
So
we
have
we
have.
We
have
an
on
F
and
this
owner
essentially
defines
what
it
means
to
defines
the
concept
of
ownership.
D
Of
that
specific
of
the
specific
token
so
the
in
the
simplest
case,
it
can
be
just
a
public
key
or
it
can
be
something
more
complex
like
like
a
script
and
so
on
and
so
forth.
We
have
a
token
as
a
type,
it's
essentially
the
denomination
of
the
token,
but
it's
really
just
a
string,
so
you
can
put
inside
this
thing.
Whatever
you
want,
you
can
even
load
the
type
with
a
Json
structure
represent
representing
your
non-fungible,
your
non-fungible
token.
D
D
If
we
are
talking
about
currencies,
so
the
the
type
will
will
represent
a
clear
denomination,
I
mean
it
can
be
sent
or
units
or
whatever
it
is,
and
then
the
amount
it's
clear
what
the
amount
means
with
respect
to
the
with
respect
to
the
time.
So
now,
then,
these
tokens
are
fungible
with
respect
to
the
same
to
the
same
type.
So
if
you
have
two
tokens
of
the
same
type
that
for
you,
these
are
fungible.
D
D
To
deliver
to
deliver
the
privacy,
so
this
is
a
this:
is
the
Decay
you
guys
you
get
the
main
components
forming
the
entire
stack,
it's
the
fabric,
token
SDK
and
the
fabric
smart
client.
These
are
two
hyperledger
Labs
projects,
so
two
different
repositories,
but
personally,
in
my
mind,
I
like
to
think
about
them
as
two
as
a
single
as
a
single
stack
that
provides
this.
D
This
application,
this
SDK
to
build
the
token
based
the
the
token-based
applications
in
a
way
that
it's
very
close
to
the
it's
very
close
to
the
business
to
the
business
logic.
You
will
see
later
an
example,
so
I
think
this
was
the
other.
The
other
important
aspects
for
us,
zero
knowledge
and
the
advanced
cryptography
like
multi-party
computational
threshold
cryptography
are
very
complex
to
handle
in
practices.
So
we
wanted
to
also
for
ourselves.
D
We
wanted
to
have
a
system
that
would
take
care
of
all
this
complex
aspects,
so
give
us
a
very
simple
API.
This
was
the
request
for
the
token
SDK.
Give
us
a
very
simple
API
to
talk
about
tokens
and
take
the
rest.
Take
take
care
of
all
the
details
so
what
it
means
to
generate
zero,
Edge
proofs
proof
here
and
there.
So
in
a
bit
more
going
a
little
bit
deeper.
We
have
multiple
layers.
So
the
token
is
the
token
SDK
is
as
multiple
layers
in
the
stack.
D
There
are
multiple
layers.
The
top
one
is
contains,
essentially
what
we
call
the
services
that
are
libraries
or
prepackaged
software
components
that
allow
you
allows
the
developer
to
build
quickly.
Token
token,
based
the
token
based
application.
So
this
is
the
part
that
is
the
super
customizable,
because
if
something
is
not
provided,
you
can
build
by
yourself
and
you
can
you
can
even
you
can
put
this
as
an
add-on.
D
For
the
token,
for
the
token
SDK,
these
services
will
will
use
the
directly
the
token
API
so
are
built
on
the
on
on
the
token
API
and
the
token
API
is
essentially
back-end
agnostic
and
also
say,
privacy,
I
agnostic.
So
the
token
APA
Pi
gives
you
a
way
to
describe
operations
of
other
tokens
and
nothing
else.
Then
this
this
course
the
cause
to
the
Token
API
are
translated
to
course,
to.
D
I
D
D
Essentially
it
doesn't
doesn't
have
any
privacy.
So
everything
is
in
the
clear
anyone
who
looks
at
The
Ledger
can
see
exactly
who
did
what
and
then
we
have
a
version
of
a
z-cat
that
the
tele
described
quickly
without
without
graph
finding
I
can
go
in
more
to
the
later
later.
What
it
means
me
encounter,
you
can
describe
Immortal
what
it
means,
but
it's
just
a
flavor
of
it's
just
a
a
driver
that
supports
it
zero
knowledge
and
protects
certain
certain
parts
of
the
certain
part
of
the
tokens.
D
So
this
structure,
this
will
be
this
layering
of
the
token
SDK
allow
us
to
quickly
change
the
driver
once
we
need,
so
we
can
upgrade
the
system
to
new
drivers
or
we
can
even
switch
at
the
beginning.
We
can
decide
what
we
want
to
use
and
the
token
API
allow
us
to
say
to
to
to
implement
application
so
without
having
to
worry
about
the
underlying
driver.
The
underlying
implementation.
D
The
goal
that
we
wanted
the
right
to
answer
application
forget
about
the
back
end
forget
about
the
the
Privacy
that
you
are:
the
complexity
of
the
zero
knowledge
proofs
and
so
on,
and
so
forth.
Just
focus
on
your
business
business
application.
Now,
how
do
we
instantiate?
How
do
we
run
this
this
guy?
So
the
stack
can
be
executed
as
a
as
a
standalone
network
node,
and
in
this
case
you
will
have
or
you
can
you.
D
You
will
have
a
topology
like
like
this,
so
you
will
have
multiple,
multiple
nodes
that
are
running
in
the
stack.
We
usually
call
them,
FSC
notes,
but
no
matter
what
these
are
notes
that
belong
to
the
application
to
the
application
system,
to
the
application
layer
and
these
nodes
not
only
talk
to
each
other,
but
they
also
talk.
They
can
talk
to
multiple
to
multiple
backhand
at
the
same
time,
so
you
might
have
multiple
Fabric
in
sensation
and
oriony
sensation,
a
basically
sensation
and
and
so
on
and
so
forth.
D
So
you
can
handle
all
this
anthropology
that
is
complex
as
as
complex
as
the
as
this
one,
but
you
can
even
embed
the
this
stack
in
your
existing
your
existing
application.
This
was
the
approach
used,
the
India
3s,
so
there
was
already
an
application
stacked
that
the
the
token
SDK
the
token
SDK
stack
has
been
simply
embedded
in
this
already
existing
application
stack.
So
maximum
flexibility,
you
can
you
don't
you
don't
have
a
simple,
a
single
way
to
deploy
the
the
smart,
the
smart
client.
D
Now,
let
me
tell
you
more
about.
Let
me
tell
you
more
about
how
do
we
achieve
the
this
decoupling
of
the
actual
implementation
of
the
token,
so
the
actual
the
details
about
the
zero
age
proof
or
any
other
technology
that
you
you
want
to
use
and
the
the
token
API
the
way
we
talk
about
tokens
in
the
context
of
the
token
SDK,
so
we
have
a,
we
have
an
object.
I
did
a
structure,
the
token
SDK
that
it's
called
a
toggle
request.
D
So
let
me
let's
go
through
so
let's
see
the
anatomy
of
this
token
regress
to
understand
what
what
it
contains.
So
the
token
is
Decay
The
Token
API
speaks
about
the
toggle
request,
so
he
knows
how
to
how
to
manipulate
this.
This
data,
this
data
structure,
it
doesn't
know
anything
in
anything
else,
at
least
from
the
point
of
view
of
the
token
API.
So
there
are
three
main
sections
in
the.
D
D
So
the
the
two
most
fundamental
actions
in
the
context
of
the
token
SDK
are
these
ones
and
the
transfer
so
issuance
allows
allows
the
allows
the
possibility
to
allow
someone
an
issuer
in
particular,
to
create
new
tokens
out
of
the
blue,
so
they
have
a
specific
section.
Inside
the
token,
the
token
request
to
specify
the
the
will
to
create
new
tokens
and
tokens
can
also
be
transferred.
D
So
there
is
a
section
in
the
token
request
that
speaks
about
the
transfer
of
tokens
from
one
or
from
a
recipient
from
sorry
from
Ascender
to
to
a
recipient.
Now,
the
the
actions
are
also
accompanied
by
witnesses
that
are
are
sure,
are
needed
to
make
to
to
to
to
convince
a
validator
that
these
actions
are
are
correct.
D
So
a
legitimate
think
about
the
the
fact
that,
if
I'm,
if
Alice
is
transferring
a
token
to
Bob
Alice
needs
to
prove
that
she's,
the
legitimate
owner
of
the
tokens
that
she's
trying
to
transfer.
So
in
the
weakness
section,
you
will
find
the
signature
from
Alice
for,
for
example,
and
then
we
have
meta.
D
Passed
the
metadata
path,
it's
very
important,
it's
it's
something
that
it's
used
to
transport,
all
these
little
secrets
that
are
needed
to
the
obfuscate,
the
zero
knowledge
proof
or
the
to
better
understand
that
the
content
of
the
actions
right.
So
the
actions
might
contain
something
like
zero
knowledge,
proof
or
cryptographic
commitments
as
something
that
is
obfuscating.
D
What's
what's
going
on,
because
we
want
the
system,
our
system
to
be
private,
but
when
Alice
and
Bob
are
exchanging
this
information
for
them,
the
content
of
the
action
should
be
like,
like
it
was
in
in
the
clear.
So
the
metadata
is
the
same
action
when
Alice
and
Bob
are
exchanging
secrets
that
are
that
allow
them
to
understand
the
actions
that
are
there
there
that
they
are
discussing.
D
So
this
is
the
the
the
the
main
the
data
structure,
that
is,
in
the
token
SDK,
and
it's
used
it's
it's
manipulated
by
the
token
API.
Then,
when
it's
time
to
store
to
to
make
it
real
to
make
these
actions
happening
and
being
settled
in
the
back
end.
We
have
the
concept
of
token
request,
translator
so.
B
D
There
will
be
a
translator
that
take
this
total
request
that
converts
it
to
the
the
data
format
understood
by
the
backend,
so
for
fabric
can
be
a
read,
write
set
for
Orion,
it
can
be,
it
can
be
another
data
structure
actually
Ryan
also
supports
a
sort
of
data
of
of
of
data,
of
read,
write
set.
What
is
important
is
that
the
metadata
are
are
stripped
out
by,
by
the
token
request,
translator,
because
you
don't
want
to
store
Secrets
right
on
the
on
the
back
end.
D
The
secrets
are
just
for
the
party,
so
I've
been
involved
in
a
specific
in
a
specific
transaction.
Let
me
let
me
give
you
more
a
better
flavor
by
taking
an
example,
so
we
understand
also
with
the
kind
of
information
that
are
exchanged
between
this
practice,
suppose
that
we
have
let's
say
in
this
example:
we
have
two
parties
Alice
and
Bob.
These
are
the
classical
names
that
we
always
use
in
cryptography,
Alice,
Bob,
Charlie
they've.
These
are
the
classical
names
that
we
use,
so
we
always
refer
to
them.
So
we.
D
And
Bob
they
want
to
exchange
they
own
the
exchange
they
want
to
perform
an
atomic
exchange.
So
Bob
Alice
wants
to
exchange
with
Bob
5
USD,
actually
in
exchange
of
five
Swiss
Francs.
So
what
they
do,
what
any
said
Bob
will
do.
They
will
start
talking
to
each
other
and
assemble
the
token
request
by
feeling
the
the
all
the
sections
of
the
of
the
token
requests
that
I
showed
you
before.
D
They
can
sign
the
terminal
requested,
so
they
can
put
their
signature
their
their
Anonymous
signatures
inside
the
witnesses,
and
then
this
object
can
be
sent
to
the
to
the
back
end
for
for
commitment
for
settlement
and
to
to
have
this
to
have
this
settle
sorry.
So
this
is
just
a
a
a
very
high
level
business
use
case
that
you
might
have
that
can
be
converted
in
actions
in
the
in
the
in
the
token,
in
the,
in
course,
the
token
token
API.
D
Now
let
me
give
you
a
sense
of
what's
what's
really
happening
behind
the
scene
when
we
have
fabric
as
a
when
we
have
fabric
as
a
baker.
So,
on
the
left
hand
side,
we
have
a
bunch
of
people,
a
business
parties.
We
might
have
more
than
two
business
parties
that
collaboratively
all
together
in
a
peer-to-peer
fashion.
They
come
together
and
they
decide
they
want
to
perform
a
certain
token
operations.
Atomically.
D
On
the
right
hand,
side
we
have
fabric
with
the
with
the
chain
code
installed
that
we
call
the
token
chain
code.
This
token
chain
code
is
the
creates
the
namespace
in
fabric
to
store
all
the
tokens
that
we
are,
that
the
the
system
manipulates
over
over
over
time.
So
now.
The
first
step
is
for
this
business
parties
to
start
communicating
and
assemble
the
token
request.
I
give
you
before
an
example
of
a
swap,
but
it
can
really
be
anything
you
will
see
with
the
API.
D
D
This
business
is,
can
be
one
or
more
signatures
coming
from
an
auditor
that
must
see
the
transaction
before
this
can
be
submitted,
submitted
to
the
legend,
Zone
and
so
forth.
So
once
the
token
request
is
ready,
what
they
do
is
that
one
of
the
one
of
them,
one
of
these
business
part,
will
invoke
the
token
shaking
program
for
a
specific
reason.
So
now
this
business
part,
they
have
the
token
request
they
strip
out
the
metadata,
because
they
don't
want
to
lick
this
price.
D
This
secrets
to
the
to
the
to
the
to
the
blockchain.
Now
the
token
chain
code
does
the
following
thing:
two
specific
things:
it
validates
the
token
request,
so
it
checks,
for
example,
the
tool
that
zero
launch
proof
are
correct,
that
all
the
invariants
of
the
payment
system
are
satisfied
like
only
the
legitimate
owner
must
transfer
the
tokens
or,
and
no
money
out
of
the
blue
is
created
by
the
system
notice
that
the
token
chain
code,
if
you
are,
if
you
are
using
the
driver,
this
supports
zero
knowledge.
D
The
token
chain
code
does
not
at
the
for
the
endorses,
do
not
learn
anything
about
the
content
of
the
transaction
because
they
see
only
zero
knowledge
proofs
right,
so
what
they
do,
they
validated
the
zero
knowledge
proof
and
if,
if
they
are
all
valid,
they
translate
this.
The
total
request
to
something
that
fabric
understand
now
notice
that
at
this
stage
we
can,
we
cannot
yet
verify
double
standing,
which
is
another
key
key
property
of
any
payment
System
payment
system,
because
the
endorsement,
as
you
know,
in
fabric
it
can
happen
in
power.
D
Multiple
endorses
can
happen
in
parallel
and
in
parallel,
The
Ledger
gets
updated,
so
the
double
spending
check
can
only
happen
at
committee
time
anyway.
We
got
the
chain
code
invoke
at
the
the
endorses
are
responding
back
to
responding
back
with
the
endorsement.
The
business
parties
now
have
everything
to
prepare
a
token
sorry
to
prepare
a
fabric
transaction
and
to
submit
it
to
the
ordering
service,
so
the
transaction
is
submitting
to
the
ordering
service.
All
the
committers,
the
ordering
service
ordered
the
transaction.
D
The
transaction
is
distributed
to
the
entire
network
and,
as
you
know
now,
the
committer
are.
The
committer
are
verifying
that
a
verifying,
essentially
two
things
that
the
transaction
has
been
endorsed
properly,
so
they
check
for
the
signature
and
they
checked
for
the
so-called
mvbc
nvcc
checks,
which
are
which
is
which,
which
are
about
conflicts
of
keys
in
the
key
value
in
the
key
value
store.
So
this
is
the
time
where
we
have
where
we
check
for
double
standing
resistance,
and
how
do
we
do
that?
D
We
essentially
the
the
translation
of
the
total
request
to
a
read.
Write
set
essentially
will
prepare
a
read,
write
set
that
will
generate
a
conflict
if
a
double
spend
happens
and
if,
if
a
conflict,
so
the
the
the
committer
will
under
we
will
understand
that
if
a
complex,
a
conflict
happens,
this
is
essentially
a
double
span
and
the
transaction
action
will
be
will
be
rejected.
So
now,
I
know
what
you
are
thinking.
This
is
very
complex.
There's
a
lot
of
steps
going
on.
How
will
you
ever?
D
D
So
when
we
try
to
do
the
same,
and
let
me
do,
let
me
give
you
an
example
of
what
it
means
to
write
an
application
with
the
token,
with
the
token
SDK,
with
the
token
SDK
API.
So
usually
you
write
what
we
call
flaws
of
views
anyway.
Units
of
computation
that
perform
perform
certain
certain
operations
and
these
units
of
computation
are
executed
by
by
the
the
FSC
nodes.
That
I've
showed
you
before
and
essentially
it's
the
token
SDK
that
takes
care
of
executing
this.
D
These
pieces
of
business
business
logic
so
remember
that
for
us
the
goal
was
we
want
something
that
doesn't
speak
about
the
underlined,
the
underlying
back
end.
We
want
something
that
does
speak
about
zero
knowledge,
proof
or
any
other
privacy
technology
trusted
execution,
environmental
computation.
We
don't
want
that
level
of
complexity
at
the
API.
We
want
something
that
is
very
high
level.
So
the
first
thing,
if
you,
if
Paris,
has
to
transfer
tokens
to
Bob
the
first
thing
the
titleists
would
do
in
general
is
a
contact.
D
Bob,
I,
say:
hey
Bob
I
need
one
of
your
one
of
your
pseudonym,
because
I
have
to
try.
I
have
to
transfer
money
money
to
you.
Why
is
this
because
we
I
we
want
to
I,
listen
Bob
want
to
perform
a
privacy,
preserving
transfer
right.
So
as
we
will
go
to
Bob
and
say
Bob,
please
give
me
one
Anonymous
identity
of
yours
that
you
will
use
only
one
and
a
pseudonym
okay,
this
is
the
recipient,
so
Bob
on
the
other
side
will
prepare
the
pseudonym
and
send
it
back.
D
The
analysts
say:
okay,
I
need
to
prepare
an
anonymous
transaction
because
I
don't
want
to
leak
any
anything
about
who
is
the
creator
of
this
transaction
and
then
I?
In
this
token,
transaction
I
want
to
want
to
perform
a
trance
where
the
transfer
tokens
that
comes
from
a
certain
wallet
tokens
or
a
certain
type
that
comes
from
a
certain
wallet
for
a
certain
a
certain
amount
and
I
want
to
give
this
token
to
Bob.
So
one
line
this
is
this
transfer
this.
D
This
call
to
the
Token
API,
essentially
load
the
token
request,
with
all
the
relevant,
the
relevant
information.
Now,
the
token
request
is
ready.
We
need
to
perform
all
the
all
that
complex
protocol
that
I
described
you
before,
but
for
the
Pro.
From
the
point
of
view
of
the
token
API,
we
just
have
a
single
call
that
it's
it's
essentially,
we
call
it's
the
collect
endorsements.
D
It
takes
care
of
everything,
takes
care
of,
contacting
all
the
business
parties
to
collect
signature,
to
contact
the
Auditors
to
to
to
contact
the
endorses
the
fabric
endorses
or
to
contact
any
any
anyone
that
needs
to
sign
this
transaction.
Depending
on
on
the
specific
back
end
that
you
are
using
for
for
this
for
this
transaction
and
at
the
end,
you
want
to
order
this,
the
transaction
that
you
can
understand
as
settled.
D
So
this
was
very
convenient
for
us
and
for
me,
and
also
to
develop
to
develop
that
other
applications.
So
here
in
this
is
from
the
the
website
from
the
token
SDK
GitHub
repo,
you
will
find
multiple
samples
that
you
can.
You
can
go
through
and
discover
a
play
with
them.
I
really
encourage
you
to
do
to
do
that
so
and
give
us
feed,
give
us
feedback
and
even
contribute
to
the
to
the
git
repo.
D
We
are
really
happy
today
to
to
involve
as
many
as
many
as
many
of
you
as
as
possible.
So
last
last
slide
before
I
take
I
I.
Maybe
I
answer
I
see
that
in
the
chat
there
are
messages,
but
before
I,
maybe
I
take
live.
Some
of
your
questions.
Let
me
remember,
let
me
recall
you
that
the
token
SDK
is
a
set
of
API
and
services
to
develop
a
token
based
that
are
distributed.
D
Applications
very
quickly
and
with
the
motto
bright
ones
play
the
right
ones,
the
sign
later,
the
back
end
and
the
Privacy
model
it's
based
on
it
uses
new
utxo
model
to
represent
the
tokens,
supports,
fungible
and
fungible
tokens.
If
there's
a
programming
model
that
is
very
close
to
the
business
to
the
business
logic,
you
can
find
more
documentation
and
samples
at
the
at
the
the
on
the
GitHub
repo,
and
you
can
reach
us
all
on
Discord
on
the
fabric
token
SDK,
with
this
I
will
stop.
D
D
So
the
chain
code
is
part
of
the
setup
of
the
of
the
the
file
if
you're
talking
about
fabric,
that's
part
of
the
the
fabric,
the
the
fabric
in
the
fabric
setup,
so
I
would
expect
that
the
administrator
one
or
more
administrators
of
the
the
network
and
the
the
four
of
the
organizations
in
the
fabric,
Network
They,
will
receive
the
token
They
will
receive
the
chain
code.
The
token
chain
code
package
they
will
install
on
the
FPS
and
they
will
they
will.
D
A
very
good
point,
so
the
FSC,
the
FSC
nodes,
will
connect
to
our
trusted
trusted
peer
to
say
in
the
same
organization
to
learn
about
which
transaction
are
committed.
So
essentially
the
FSC
know
the
leverage,
the
delivery
service
of
the
fabric
piece
to
learn
about
the
water
to
learn
about
the
status
of
each
of
each
transaction.
D
Of
course
you
need
to
take
care,
because
you
want
your
FSC
note
to
connect
to
either
trusted
peers
or
to
connect
to
in
in
the
same
organization
or
to
connect
to
multiple
peers
and
to
take
the
majority
of
their
or
their
or
their
answer.
Oh,
but
I
feel
like
I,
now
I
see
the
Torso
earlier
around
said.
Oh,
maybe
I
don't
have
to
then
I
feel
there
are
already
many
answers,
so
maybe
I
can
I
don't
have
to
to
take
further.
D
E
E
Let's
say
cbdc
for
Securities
and
you
want
to
have
this
exchange
happens
atomically
in
the
sense
an
entity
can
only
receive
the
Securities
if
they
pay
for
it,
and
vice
versa
and
the
Second
Use
case
is
asset
transfer,
and
this
is
basically
reflects
the
movements
of
assets
from
one
network
to
the
other.
As
the
current
time
Primo
mentioned
earlier,
in
the
asset
exchange,
we
are
assuming
that
the
cbdc
resides
in
one
network.
E
Let's
say
the
destruction
of
the
asset
in
the
source
Network.
So
the
first
thing
we
will
start
with
is
acid
exchange
and
we
start
with
sort
of
like
an
overview
like
or
like.
Let's
say
the
basic
use
case
that
we'll
try
to
address
when
we
talk
about
assets
exchange.
So
here
we
assume
that
we
have
Alice
involved,
so
we
have
Alice
in
network
a
and
for
Simplicity
we
say:
okay,
this
network
is
for
euros
and
Alice
and
Bob.
They
are
both
on
the
same
network.
E
And
what
is
very
important
to
keep
in
mind
here.
Is
that
hdlc
or
let's
say
this
asset
exchange
or
the
Assumption
in
this
asset
exchange?
Is
that
Alice
and
Bob?
They
are
rational
and
they
are
online
and
it
will
become
apparent.
While
we
have
this
assumption
like
why
they
should
be
rational
and
be
online,
especially
if
we
are
using
hdlc
for
the
asset.
Exchange.
E
So
so
I
think
Corona
already
and
already
described
the
bits.
How
hcsc
looks
like-
and
here
I
will
just
sort
of
expand
on
that.
So
when
it
comes
to
HTC
what
you
are
the
first
thing
that
would
happen
or
the
first
interaction
that
would
happen.
It
would
be
Alice
in
Bob
agreeing
on
the
terms
of
the
contract
and
here
the
terms
of
the
contract.
E
If
we
go
with
the
example
I
presented
in
the
previous
slide
would
be
alisonia,
I
will
pay
100
euros
for
100
ebones,
and
then
there
are
other
elements
that
are
specific
for
htsc
and
those
are
the
hash
and
the
timeout.
So
those
are
kind
of
Also,
let's
say
in
some
way
are
part
of
the
contract,
and
here
for
Simplicity
or
like
just
for
the
sake
of
Clarity,
we
would
assume
that
Bob
is
the
one
Computing
the
hash.
E
So
this
is
agency
is
asymmetric
in
the
sense
when
we
start
the
hclc,
Alice
and
Bob,
they
do
not
know
the
same
information.
For
example,
in
this
case
we
have
Bob,
he
would
pick
a
secret
value
X
and
we
will
compute
the
hash
of
X
and
Alice
will
only
know
the
hash
at
the
time
when
we
start
the
hlc,
so
Bob
will
compute
this
hash
of
X.
He
will
send
the
hash
of
x
to
Alice
and
Alice
would
based
on
this
hash
of
X,
based
on
the
time
out.
E
They
agreed
on
and
based
on
the
terms
of
the
contract,
which
is
like
yeah
I
will
transfer
to
100
euros
to
100
ebones.
It
will
create
a
transaction
for
Bob
and
Bob
will
do
also
the
same
for
us
and
here
and
it's
something
that
is
very
important
to
keep
in
mind
here.
Is
that
whoever
knows
the
secret
that
is
behind
the
hash
should
be
the
first
entity
to
submit
the
transaction.
E
So
here
we
have
Bob,
knowing
the
secrets
behind
the
hash,
so
Bob
is
required
to
First,
submit
the
transaction
into
this
network
where
we
have
the
Securities,
because
Bob
here
would
like
to
transmit
the
security
and
the
transaction
that
Bob
would
submit,
will
lock
the
100
ebones
for
Alice,
and
it
will
specify
what
we
call
unlocking
conditions.
And
here
the
unlocking
conditions
are
Alice
reveal
X
before
a
timeout
which
is
in
this
case
the
double
of
the
time
of
the
agreed
upon
or
if
Alice
doesn't
meet
this
condition.
E
E
Once
Alice
sees
that
this
transaction
will
successfully
submitted
into
the
Securities
Network,
she
will
go
and
submit
her
transaction
into
the
Euros
Network.
So,
basically,
here
the
Locking
conditions
of
the
transaction
that
Alice's
submits
is
that
yeah
Bob
reveals
the
secret
key
behind
the
hash,
which
is
the
hash
of
X.
E
Before
the
timeout
elapses
here,
the
timeout
will
be
T,
whereas
in
Alice
transaction,
whereas
in
Bob's
transaction,
the
timeout
was
Double
T
and
if
God
does
not
reveal
the
secret
before
this
timeout
elapses,
then
Alice
would
be
able
to
just
get
out
would
be
able
to
just
get
back
her
100
euros.
So
it's
very
important
that
this
order
of
the
submission
of
transaction
is
respected,
because
if
we
flip
this
order,
what
happens
is
that
Alice
would
submit?
E
Let's
say
first
that
transaction
Bob
does
not
have
to
submit
his
transaction,
because
the
moment
that
transaction
is
submitted
by
Alice,
he
can
just
claim
it,
because
he
knows
the
secret
key
to
claim
the
token
that
Alice
locked
in
her
transaction.
So
it's
very
important
that
whoever
knows
the
secret
of
the
hash
is
the
first
party
to
submit
the
lock
the
first
party
to
submit
the
lock
transaction.
E
So
this
is
like
classical
hdst
and
and
token
SDK
will
provide
support
for
the
for
this
htlc
in
a
very
simple,
let's
say
manner,
so
we
we
kind
of
the
token
SDK-
does
not
necessarily
care
about
how
the
terms
of
the
contract
are
kind
of
agreed
upon.
So,
as
I
said,
the
terms
of
the
contract
would
be
the
plan
out.
The
hash
that
is
the
the
hash
that
is
would
be
used
in
the
htmc
plus
the
value
and
the
type
in
basically
the
sender
in
the
recipient.
E
So
those
terms
are
agreed
upon,
let's
say
out
of
band,
although
in
the
token
SDK.
Actually
we
provide
new
mechanisms
that
allows
one
to
have
these
interactions,
but
for
Simplicity
we
just
assume
that
we
get
this
information
out
of
them.
And
now
we
say
that
for
the
support
HTC,
the
owner
of
a
token
and
the
token
SDK
can
be
an
htsd
script
and
an
HTC
script
is
specified
very
simply
so
it
just
have,
let's
say
four
Fields.
E
Basically,
it
identifies
a
sender,
it
identifies
the
recipients,
it
has
a
hash
and
a
timeout
and
then
a
lock
of
a
token
and
the
token
SDK
corresponds
to
transferring
this
token
through
this
HSC
script.
So
basically,
this
is
a
token
whose
owner
would
be
this
HJC
script.
So
if
we
go
back
to
what
Angelo
presented
saying,
okay,
we
have
a
token
that
has
a
type
of
value
owner
to
support
HTC.
We
do
not
have
to
change
the
definition
of
the
token
we
keep
the
definitions,
as
is
we're
just
kind
of
extend
what
an
owner
is.
E
So
in
our
case
now
an
owner
could
be
an
HTT
script,
which
is
defined
by
Portugal.
Sender
is
an
identity.
Recipient
is
an
identity,
and
passions
are
just
like
a
string
and
duration,
and
we
provide
a
simple
API
to
kind
of
build
the
transaction
for
login
at
token
for
the
htlc
script.
So
we
have
the
log
that
takes
the
sender
wallet.
It
takes
the
recipient,
it
takes
the
value,
the
type
and
the
hash
in
the
timeout.
E
Now
there
is
decline,
operation
which
corresponds
to
the
Happy
pack,
so
basically
Alice
in
Bob
are
both
online
are
both
willing
to
complete
the
cycle
of
the
SJC
script.
So
the
moment
they
see
a
log
transaction,
they
would
claim
condition
on
them
receive
like
condition
on
them,
knowing
the
pre-image
of
the
hash
and
the
in
the
script.
E
So
here
the
claim
would
just
have
the
recipients
wallet
it
will
have,
it
will
identify
the
locked
token
and
it
will
take
the
pre-image
and
why
we
do
have
the
recipient
wallet.
Is
that
the
unlocking
of
the
token
is
not
only
show
me
the
pre-image,
but
also
show
me
that
you
are
the
recipients
identified
in
the
HJC
script.
So
we
say:
okay
I
have
to
see
pre-image,
but
this
premise
should
be,
as
should
be
actually
sent
by
the
recipient
and
the
HTC
script.
E
So
the
recipient
needs
to
sign
this
transaction
in
addition
to
providing
the
payments.
So
what
what
the
claim
does
is
very
straightforward:
it
will
just
transfer
the
ownership
of
this
locked
token
to
the
recipient.
So
basically
we
just
sort
of
changed
the
ownership,
so
the
owner
fees
now
is
no
longer.
The
script
is
going
to
become
the
recipient
and
again
the
claim
is
just
a
transfer.
So
under
the
hood,
the
claim
use
the
transfer
that
was
presented
earlier,
By
Angelo.
E
Now
this
is
the
claim
which,
as
I
said,
is
the
happy
path.
So,
basically,
both
parties
decide
to
just
continue
the
protocol
and
sort
of
claim
the
assets,
the
reclaim
for
response
to
what
you
could
think
of
as
the
unhappy
path.
So
basically,
for
example,
Alice
Bob
submitted
his
transaction
Alice
submitted
her
transaction,
but
then
Bob,
for
whatever
reason
decides
just
not
to
continue
so
he
doesn't
submit
the
pre-image.
So
in
that
case,
Alice
can
reclaim
for
token
and
the
way
to
do
that
is
just
she
sort
of.
E
So
here
what
we
have
the
reclaimers,
like
the
as
I
said,
the
Greek
lamp
corresponds
to
what
we
could
think
of
as
the
unhappy
path
in
the
sense.
Bob
doesn't
claim
the
token
and
doesn't
reveal
the
privilege.
Then
Alice
just
go
and
reclaim
her
token
and
the
reclaim.
Let's
say
API
is
again
very
simple:
we
just
have
the
sender
wallet
and
the
lock
token.
E
E
We
have
this
time
out,
for
example,
G,
so
we
could
easily
imagine
that
if
Bob
reveals
X
writes
after
T
elapses
like
he,
he
wanted
to.
He
wanted
to
kind
of
claim,
but
for
whatever
reason
the
the
transaction
was
delayed
and
what
or
he
just
kind
of
did
not
submit
the
transaction
like
as
early
as
possible.
E
What
could
happen
is
that
Bob
would
reveal
X
right
after
she
elapses
and
then
he
he
cannot
claim,
because
the
condition
is
that,
like
you,
have
to
make
sure
that
you
submitted
it
before
the
time
time
out
elapses.
But
then
Alice
now
has
X.
So
she
can.
She
could
claim
it
the
the
asset
that
Bob
locked
for
her,
because,
especially
at
this
time
out,
this
Double
T
has
not
elapsed.
E
E
E
So
the
way
we
Implement
asset
transfer
or
the
way
we
think
about
asset
transfer
is
that
to
implement
it.
What
we
do
is
that
we
let's
say
we
assume
that
Alice
would
like
to
transfer
100
euros
to
Bob.
However,
Alice
is
in
network
a,
whereas
Bob
is
in
network
P,
so
they
do
not
reside
in
the
same
network.
So
Alice
cannot
just
send
the
assets
to
an
address
in
her
network,
because
Bob
is
not
part
of
that
Network.
E
So
what
Alice
does
is
that
like
say,
okay
I
will
send
the
address
the
the
asset
cross
networks.
However,
it's
very
important
to
ensure
that,
like
when
Alice
sends
this
asset
cost
networks
that
the
assets
is
destroyed
in
her
network
and
it
is
created
in
Bob's
Network
and
that
this
destruction
and
creation
of
asset
is
atomic.
It
also
preserves
value.
E
So
again
when
we
go
back
to
the
Token
SDK
and
what
Angelo
presented
the
token
SDK
has
tokens
that
are
defined
just
as
owner
typing,
on
just
as
owner
typing
value.
So
we
do
not
have
anything
that
is
sort
of
dedicated
for
cross
Network
transfers,
and
we
do
not
really
want
to
extend
the
token
definition
just
to
support
this.
E
But
what
we
do
is
that
we
say:
okay,
the
owner
and
the
token
SDK
is
quite
flexible
because
it's
just
a
stream
of
bytes-
and
we
said
okay,
now
we
would
specify
an
owner
which
is
a
script
like
what
we
did
with
the
HTT
and
the
script.
We
call
it
like
a
pledge
and
the
split
script
sort
of
specify
under
which
condition.
E
E
E
Let's
say
this
cross
network
transfer
and
then
Alice
would
notify
Bob,
because
Bob
does
not
have
a
way
to
know
if
the
token
was
pledged
for
them,
because
he's
not
part
of
that
Network,
so
Alice
would
notify
Bob
and
say:
okay,
I
locked
a
token
for
you,
and
it
will
give
him
identifier
of
this
token
again,
because
Bob
is
not
part
of
that
Network.
He
cannot
just
like
take
Alice's
word
for
Alice's
word
like
for
granted,
because
Alice
could
just
be
lying.
E
So
what
Bob
does
is
that
he
uses
a
relay
service
which
is
kind
of
provided
by
the
hyper
Ledger
we
were,
and
this
is
a
relay
service
that
is
trusted.
Let's
put
it
this
way
by
his
Network,
so
Bob
leverages
this
realized
service
to
get
to
proof
that
actually
this
there
is
a
token
and
Alice's
Network
that
is
pledged
for
him,
so
he
would
sort
of
contact
the
relay
service.
E
He
will
get
this
proof
and
he
would
inspect
that
this
token
and
the
proof
are
valid
and
that
the
token
actually
corresponds
to
whatever
he's
expecting
and
then
Bob
would
contact
the
issuer
in
his
Network.
So
whoever
is
responsible
for
the
introduction
of
tokens
in
the
system,
his
Network,
they
will
contact
them
and
they
will
contact
them
with
the
proof
they
have
received
from
the
relay
service.
E
Now
the
issuer
would
check
that
the
proof
is
valid
and
then
they
will
check
that.
Actually,
the
time
out
has
not
allowed
because,
as
I
mentioned
at
the
beginning,
Alice
would
specify
a
time
out
before
which
a
bob
can
claim
the
token.
So
if
either
the
proof
is
invalid
or
that
out
has
elapsed,
the
issue
will
just
reject,
so
he
would
just
decide.
Okay,
I'm
not
going
to
create
the
token.
However,
if
these
two
conditions,
if
the
conditions
that
is
like
the
time
of
does
not
elapsing,
the
proof
is
valid,
are
met.
E
E
We
will,
we
will
kind
of
yeah.
This
is
what
will
be
actually
addressing
now
so
again,
as
I
said
the
scripts.
The
script
specifies,
as
I
said,
that
this
is
a
token
for
Bob.
Bob
is
in
a
certain
Network
and
that
this
is
the
time
out.
They
also
specify
another
information,
which
is
the
identity
of
the
issuer
and
the
origin
Network,
which
would
help
the
sender
to
reclaim.
E
We
just
talked
about
claim
because
in
this
slide,
we'll
talk
about
Clement
decline.
So
again,
at
this
token,
would
rely
on
invoking
this
relay
service
to
get
a
proof
that
says.
Okay,
there
was
a
pledge
token
pledged
for
Bob
in
network
in
Alice's
network
Bob.
Then
they
will
invoke
the
issuer
with
the
proof
and
then
the
issue
will
check
yeah.
E
So,
basically,
it's
very
important
to
have
the
this
proof
that
it
does
not
exist
attached
to
like
proof
that
the
time
of
this
query,
whether
the
token
existed
or
not,
is
larger
than
a
certain.
As
for
the
ownership
of
a
token
to
a
pledge
script.
The
way
we
do
it
is
by
calling
this
pledge
function
which
take
the
standard
wallets,
the
destination
of
the
destination
network
of
the
recipients,
the
deadline,
the
identity
of
the
recipients,
the
issuer,
as
I
said.
E
This
is
mostly
to
help
the
sender
reclaim
in
case
some
issues
happen
with
the
claim,
and
then
there
is
a
unique
pledge
ID.
Then
there
is
Type
in
value,
and
this
pledge
will
create
a
log
token
that
has
as
an
owner
pledge
script.
Then
we
have
the
claim
method
and
this
is
invoked
by
the
recipient
and
it's
sort
of
has
a
very
simple
again
interface.
So
we
have
the
issuer.
E
We
have
the
type,
the
value,
the
recipients,
the
I,
the
identifier
of
the
token
that
has
been
pledged
and
the
origin
Network
and
then
the
proof-
and
here
the
proof
is
the
proof
from
the
relay
Network.
That
says
that
the
token
has
been
pledged
and
the
reason
we
have.
The
proof
here
include
included
in
the
claim
is
more
for,
let's
say
auditability
purposes
and
sorry
I
mean
I
mentioned
that
the
claim
is
submitted
by
the
by
the
sen
by
the
recipient,
it's
not
submitted
by
the
recipients
or
it's
submitted
by
the
issuer.
E
So
the
claim
is
the
one
source
of
submits
in
this
transaction
and
again,
the
claim
will
just
create
a
token
for
the
for
the,
for
the
second
reclaim
will
transfer
again.
As
we
said,
the
ownership
from
the
script
to
the
sender
and
the
way
this
is
performed
is
by
Conan
the
method
reclaim
which
has
its
arguments.
The
sender
The
Pledge
token,
the
issuer
signature
that
was
received
by
the
sender
and
sorry
and
the
proof-
and
this
reclaim
would
just
create
a
token
for
the
sender
again.
E
These
are
sort
of
a
bit
of
a
low
level
methods
in
the
sense
and
token
SDK
repo.
We
have
applications
that
sort
of
handle
everything
you
see
here,
so
basically
it
they
had
it
had
like
you,
you
see
a
method
that
sort
of
orchestrates
the
interaction
between
the
sender,
the
recipient,
the
relay
service.
So
this
is
something
that
whoever
is
developing
applications
for
this
cross-network
transfer
do
not
have
really
to
worry
about,
because
it's
taken
care
of
by
the
by
the
token
SDK.
E
C
C
C
D
C
So
I'm,
so
the
if
you're,
referring
to
the
architecture
of
a
two-tier
like
a
two-tier
architecture,
I,
don't
think
I
can
answer
this
question.
I
know
that
it
has
been
the
recommended
one
by
pretty
much
all
of
the
Central
Bank
digital
currency
reports
of
central
banks,
and
there
have
been
more
than
60
at
this
point.
That
I,
as
I
mentioned
dlt-based
architectures
for
the
wholesale
cbdc
is
there
is
consensus
that
there
is
a
alignment.
I
Sdk
I
meant
yeah.
This
is
sitaram
yeah.
Whatever
you
presented
right
in
the
last
slides
the
term
yeah
I'm
wondering
if
that
architecture
or
similar
architecture
being
used
by
any
you
know
Federal
governments
in
the
world.
You
know
because
I
know
of
China
they
they
have
implemented
cbdc
one
year
more
than
a
year
and
India
is
its
in
the
initial
stage
of
implementation.
So
I'm
just
wondering
if
any
of
them
are
Japan
is
in
plan.
I
C
Okay,
I
will
respect
to
say
that
there
is
definitely
a
very
Advanced
interest
on
the
token
SDK,
but
unfortunately
not
able
to
say
more
than
that
yeah,
so
wholesale
and
and
Retail
essential
language
or
currencies.
Much
stakeholders
are
multi
seen
with
interest
token
ski
capabilities
I
mentioned
because
of
the
combination
of
privacy
and
and
regulation
compliance
particular
audit
support.
C
So
token,
SDK,
but
also
hyperledger
fabric,
comes
for
wholesale
essential
boundaries,
so
currency
quite
relevant,
as
I
mentioned
before
the
same
holds
from
I
mean
I
mean
I,
don't
know
if
if
David
has
something
more
to
others
as
a
hyperledger
but
from
I
I
know
for
sure.
If
you
use
the
Central
Bank
digital
currency
tracker
the
web
page,
you
would
be
able
to
see
quite
a
few
experimentation
until
it's
looking
at
hyperledger
fabric.
But
there
are
also
some
Advanced
versions
of
those
but
I'm
I'm.
A
I'll
just
add
one
thing
and
I'll
drop
a
link,
I
mean
in
terms
of
case
studies
that
we
can
talk
about
publicly.
There
are
a
number
of
published
case
studies
on
the
hyperledger
website,
not
all
of
them
necessarily
related
to
cbcs.
It
kind
of
covers
a
range
of
different
use
cases,
but
there
are,
you
know
there
are
some
deep
dive
case
studies
there
and
some
of
them
do
touch
on
this
topic.
So
you
feel
free
to
check
out
that
link.
J
And
for
the
attendees,
we
are
going
to
send
out
a
thank
you
email
with
links
to
the
video
relevant
links.
If
we
can
get
the
decks
from
the
presenters,
all
that
will
be
up
there
and
you
can
also
find
them
if
you,
if
you're,
not.
If
you
don't
get
that
we
have
a
link
to
the
Wiki
page.
For
this
event,
at
the
top
of
what
I
just
put
in
the
chat.