►
From YouTube: TokenScript Weekly Meeting 20200507
Description
00:46:32 weiwu: https://github.com/AlphaWallet/blockchain-attestation/blob/master/use-cases/email-address-attestation.md
00:58:19 Tore Frederiksen: We can’t hear you Weiwu
00:59:00 JamesB: no audio
01:20:37 weiwu: Helolo\
01:20:59 weiwu: https://github.com/AlphaWallet/blockchain-attestation/blob/master/use-cases/email-address-attestation.md
01:21:27 weiwu: Alice signs msgData to transfer ETH. (msgData specifies expiry, ETH amount)
Alice securely sends signed msgData to Bob (email, telegram, ...).
Bob calls Alice's smart contract wallet with h(msg + BobAddress) (aka msgHash)
- smart contract checks: msgMap[msgHash] == 0 (not used)
- smart contract stores: map[msg.sender] = msgHash
Bob calls Alice's smart contract with signed msgData
- smart contract checks msg signature of Alice
- smart contract checks: msgMap[msgHash] = 1 (used)
- smart contract checks map[msg.sender] == h(msgData + msg.sender)
- executes transaction with msg data (check expiry, send ETH)
01:27:51 Victor Zhang: https://community.tokenscript.org/t/send-with-attestation-and-send-to-attestation-mvp-use-case-of-attestation/309
B
Strange
every
time
when
I
join
a
meeting
room,
it
automatically
defaults
to
my
computer's
built-in
built-in
microphone,
which
is
no
existing
and
not
microphone
at
the
speaker
and
the
speaker.
The
correct
speakers,
HDMI
speaker,
but
I
still
have
to
have
to
select
it
every
time
so
toys
there
and
the
food
is
there
we're
waiting
for
James,
Brown
right.
C
B
B
B
B
B
B
B
So
the
poor,
you
are
happy,
sorry
and
thought
you
are
and
you
can
turn
off
microphone.
Sorry,
speaker
anytime,
you
like,
because
I'm
going
to
walk,
you
walk
your
Apple
and
brown
through
this
protocol
right.
You
already
know,
and
you
can
just
spend
the
time
to
check
the
formulas
being
correct:
okay,
yeah!
You
can
just
ignore
us,
okay,
so
so
Jamison
Boone
do
I
get
attention
to
start
from
the
first
line
of
protocol.
B
B
B
B
B
B
Bob
guess
why
by
calculate
this,
of
course,
Bob
can
do
this.
So
why
would
a
thority
give
Bob
such
authorization
that
attests
Bob
have
an
email
address
represented
by
Y?
That's
because
the
authority
knows
Bob's
email
address
which
can
be
written
as
X,
and
the
additional
salt
does
not
have
any
impact
the
therapy's
capacity
to
a
test,
because,
if
I
test
it
you
have
an
email
address,
X
I
can
test
that.
If
I
test
it,
you
have
email
address
s,
and
you
know
a
random
number.
Why
I
rent
them
number
like
three?
B
B
B
B
B
B
B
B
B
C
B
B
F
B
Okay,
so
yeah,
because
somebody
just
want
to
say
something
professional
in
the
game
and
it
doesn't
matter
if
nobody
wants
really
argue
with
him.
It's
just
like
it.
It
makes
makes
the
discussion
look
professional
from
that
point
on
yeah
all
right,
so
so
the
next
one,
the
improve
improve
the
version.
Sorry
apone
I
had
to
have
any
other
questions.
Shall
we
go
over
the
improvement
right.
C
B
A
A
D
D
B
B
B
Okay,
so
this
is
how
it
works
right,
yeah,
okay,
okay,
so
so
today's
goal
is
to
build
the
station
data
objects.
Okay,
the
build
all
the
data
objects
need
before
this
protocol
so
that
we
can
start
encoding
them
as
a
pilot
project
of
proving
how
the
destination
data
objects
in
in
in
in
focus,
script,
work.
So
I'm
going
to
stop,
sharing
and
I'm
going
to
show
you
the
link
of
this
document
and
I'm
going
to
start
working
on
the
message
with
a
new
new
new
window.
Okay,.
B
B
B
B
B
H
B
G
B
B
H
B
A
If
that's
by
the
egg,
then
again
it
depends
a
bit
on
the
policy
of
what
we
want,
because
I
mean
you
might
want
to
change
your
key
at
some
at
some
point,
yeah
I,
don't
know
I
mean
like
like
the
issue
is,
if
you
compromise
to
email
and
get
an
attestation
showing
that
you
own
that
email
that
you
can
put
in
your
home,
the
new
thing
you
can
can
put
in
your
public
key
and
reclaim
the
fonts
quest
boom
yell.
If
we
only
allow.
B
So
this
is
so
that,
like
it
in
the
protocol,
where
you
send
it
to
someone
by
email
address,
it's
implied
that
email.
This
person
owns
the
email
address
you
can.
You
can
make
this
more
difficult
by
having
a
short
expiry.
So
the
third
message
check
sound
about
Ellis
is
the
time
where
you
can
examine
the
expire
of
that
check.
H
B
A
B
A
Yeah
I
mean
like
what
we
could
do
if
we
were.
If
we
wanted
to
assume
I
trusted
a
trusted
channel,
it
would
basically
just
be
that
Ellis
makes
a
new
key
pairs
and
transfers
the
fonts.
Let's
do
that
and
since
since
the
key
I
mean
then
she
still
s,
then
it's
not
really
locked
in
a
second.
You
know
take
it
back
since
she
also.
B
H
B
H
B
B
B
B
D
B
B
It's
the
same
reason
James
a
key
that
we
don't
include
how
to
when
we
do
secret
cherish
and
maybe
secret
sharing
protocol.
We
don't
writing
the
protocol.
How
frequently
a
adversary
is
able
to
crack
the
system
by
repeatedly
trying
different
passwords,
because
that
can
always
be
added
on
top
of
the
protocol.
Okay,.
H
B
A
it
can
be
recovered
from
the
signature
and
I
think
we
discussed
that
in
there
yeah
in
the
in
the
last
session,
whether
or
not
we
included
the
game
for
extra
safety
and
I
think
at
that
time
we
didn't
include
it
because
it
would
make
the
magic
link
format
too
long.
But
if
you
argue
that's
it,
the
CSR
is
never
a
magic
link,
so
you
can
put
it
back
so
I
don't
really
mind.
Put
it
there
or
not.
There.
B
B
B
B
E
B
B
C
F
C
B
B
G
A
B
B
B
B
A
H
A
A
A
H
H
H
H
H
H
H
H
H
H
B
A
So
so
I
think
basically
was
an
important
thing,
Saki
mentioned
like
which
one
we
actually
considering
here,
because
I
mean
we
do
assume.
The
email
is
somewhat
of
a
secure
channel
right
in
in
this
I
mean
it
like
like
using.
This
flow,
allows
us
to
basically
ensure
that
Alice
cannot
basically
claim
the
money
back
after
trying
trying
to
transfer
it
or
like
give
the
key
and
parallel
to
other
people.
A
I
mean
just
knowing
and
so
I
think
the
other
thing
is
just
knowing
the
seed
itself.
It's
not
you
know
enough,
you
need
you
need
to
have
this
access
station
that
you
control
that
the
mail
account,
so,
even
even
if
it's
intercepted,
because
one
of
the
clients
meaning
service,
does
not
use
TLS
or
something
like
that.
That
still
wouldn't
be
enough.
You
would
still
have
to
compromise.
The
users
may
not
come
and
get
this
get
another
station.
B
D
A
H
F
B
It's
just
like
an
this
thing.
This
is
the
thing
we
have
to
divide
developing
for
software,
it's
not
secured
by
protocol
and
the
the
third
thing
being
that
Alice
and
Bob
can
use
some
advanced
technology
like
a
nice
mic.
Sorry,
two
bands
Ellie's
concerned
the
link
to
Bob
through
and
Carrie
grandma
SMS
and
then
Bob
is
able
for
dealing
with
his.
B
You
know
address,
and
this
is
difficult
to
do
if,
if
the
scene
is
just
sent
directly
because
then
you
have
to
rely
on
security
of
one
channel
and
last,
is
that
some
security
environments
can
be
implemented
on
the
authority
side.
So
Authority
can
have
a
policy
not
to
issue
email
address
station
too
frequently,
for
example,
yeah.
A
B
B
B
B
H
H
B
B
H
So
the
way
to
protect
it
here
again,
the
way
I've,
maybe
looked
at
her
with
other
things-
is
pre
committing
a
hash
of
what's
being
sent.
Something
like
maybe
the
message,
data
and
the
address
is
hashed
pre-committed,
and
then
you
follow
up
with
your
message
signed
message
and
you
can't
fund
run
that,
because
you
don't
have
the
address
and
a
hash
won't
add
up.
That's
just
another
way:
I've
known
it
to
work.
B
G
B
Okay,
this
is
a
simplified
version
that
doesn't
touch
email
at
all
and
it
would
it
would
still
work.
Actually
it
would.
Work
is
not
as
secure
as
email
one
because
it's
security,
male
1,
okay,
compare
this
one
with
Justin
being
deceived
football
one
of
the
month
advantages
Ellis
doesn't
have
to
protect
her
side
barbers,
you
have
to
protect
his
interest,
and
the
second
advantage
is
that
this
protocol
ensures
Bob
takes
money
out
immediately.
So
this
wouldn't
work
and.
B
G
A
H
A
H
I
guess
that's
where
I'm
trying
to
scope
the
original
problem
that
we're
we're
not
we're
so
way
we
were
assuming.
We
don't
have
multiple
ways
to
connect.
We
just
have
the
email
and
for
that
to
be
successful,
not
only
must
we
have
the
email,
but
the
person
must
be
able
to
have
another
service
that
uses
the
email
to
a
test.
Yeah.
B
B
If
you
want
to
accept
attestation,
I
can
give
me
an
email
chat
station,
but
if
you
want
in
the
game
the
next
day,
there
might
be
something
because
the
the
test
issue
is
issued
to
Bob
in
a
secure
Channel,
because
the
tester
already
know
Bob's
public
key.
It
can
encrypt
the
data
station,
so
Bob
shouldn't
have
the
reason
to
you
know:
I
receive
a
magic
link
and
they
immediately
ask
for
new
attestation.
H
Okay,
sir
yeah,
so
a
central
attestation
entity
exists
and
is
trusted
and
is
used
by
person,
the
recipient
and
the
sender
then
only
needs
to
send
one
thing
via
email
to
be
successful.
The
alternative
is
if
they
had
to
send
two
things,
then
that's
that's
yeah.
Either
they
send
it
separated
by
time
or
they
send
it
separated
by
channels
if
they
have
multiple
channels.
So
I'm,
just
trying
to
think
of
the
practicality
of
which
of
what
we're
designing.
H
B
H
B
H
Yeah
thanks
I
just
did
yeah
in
the
strong
bird
but
I
and
it's
just
the
way.
I
did
you
know
the
faux
random
is
sort
of
like
a
commit
and
a
reveal
type
scenario,
and
it
can
probably
be
made
a
bit
better
with
seed.
But
the
assumption
here
is
that
you
have
one
secure
channel
and
it's
a
signed
message.
Maybe
it's
no
different
to
sending
a
seed
so.
B
H
G
H
A
B
H
H
B
H
B
A
B
A
H
H
H
B
H
B
B
H
B
B
H
E
E
B
B
And
the
investor
is
not
supposed
to
invest
without
one
of
the
security
advice
should
being
able
to
provide
such
a
device.
That
will
be
one
example,
and
the
other
example
is
a
line
of
credit
issue
year
is
able
to
attest
that
the
the
person
who
is
Dumas
shipping
has
a
limited,
a
responsibility
of
the
products.
They
are
shipping.
B
B
B
H
So,
on
the
first
point
around,
what
was
he
saying,
yeah
about
email
being
compromised?
Part
of
that
I
guess
is
slightly
mitigated
against
with
expiry
on
those
things.
So,
if
they're
very
short-lived,
then
at
least
that
protects
the
future
of
a
past
thing
and
the
other
one.
You
said
yet
attestation
generally
in
business,
yeah
I,
can
understand
that
and
that's
I
guess
more
than
just
signed
messages,
it's
more
than
just
claims
like.
H
H
B
The
case
that
we
often
come
across
but
doesn't
have
a
100%,
so,
for
example,
in
many
cases
you
can
put
attestation
on
the
transaction
issue
here
instead
of
in
the
transaction.
So
what
you
typically
do,
is
you
log
in
to
a
website,
and
the
website
is
called
a
certified
investment
bottom
and,
alternatively,
instead
of
attesting
to
the
transaction?
B
H
Mean
I
agree
that
in
there
will
be
circumstances
that
need
attestations
or
yeah
I,
understand
that,
but
in
terms
of
existing
work
into
like
a
zero
knowledge
proof
and
that's
a
form
of
non
revealing
area
like
proving
something
without
revealing
the
knowledge
of
the
thing.
That's
useful
in
those
scenarios
right
verify.
B
B
So
you
know
if
you,
if
you,
if
you
only
need
to
be
a
tested
for
let's
say
your
hotel
is
certified
to
run,
provide
a
business
service.
You
can
probably
use
sir.
Not
proof,
although
attributed
attribute
based
proof
is
easier
and
cheaper.
You
can
probably
use
that,
but
in
the
case
of
a
specific
case,
where
traceable
case
like
this
one,
you
Ellis
can
write,
a
check
requires
Bob
to
provide
zero
to
prove
that
he
owns
Bob
at
example.com
email
address
and
then.
G
H
B
H
It
could
be,
could
maybe
just
I
mean-
maybe
not
obviously
not
for
now,
but
just
a
couple
of
those
distinct
examples
that
that
pushed
one
boundary
and
another
like
one
saying
with
these
assumptions.
This
is
where
this
solution
applies.
With
these
other
assumptions
or
these
relaxed
constraints,
this
is
where
this
other
solution
applies.
So
we
just
have
that
coverage
because
I
know
we
started
with
the
email
attestation,
but
then
I
was
wondering
well,
what
is
the
specific
requirements
for
us
to
need
this
solution
and
it
obviously
applies.
F
F
I
basically
went
on
when
the
design
Corder
they
designed
it
with
very
much
and
for
you
to
be
easily
making
after
stations
like
the
way
that
the
whole,
and
even
that,
the
way
that
the
money
on
it
works
is
basically
in
a
at
a
station
chain.
It's
quite
clever.
It's
like
oh,
like
we,
we
kind
of
didn't
want
to
like
it,
but
it
we
became
fans
of
it
how
how
it
works.
It's
basically
works
through
chain
devastations
and
yeah,
like
we
were
saying
the
things
that
people
came
up
with.
F
B
H
B
B
F
F
H
B
Even
a
station
will
reuse
it.
So
I
can
give
you
example.
You
are
able
to
sign
up
a
newsletter
on
the
website.
If
it's
worth
three
that
except
attestations,
then
you
can
sign
up
for
a
newsletter
proving
that
your
own
direct
address
email
address
without
having
to
check
the
code
or
that
if
you
do
share
secret
sharing
and
as
a
second
adapter,
you
need
to
provide
your
email
address.
B
Instead
of
the
partnership
with
Sharon
parties,
send
you
in
a
very
email
verification
code,
as
you
provide
password,
which
is
then
distributed
impasto
protocol
to
them,
you
might
as
well
just
do
the
sharing
of
password
and
the
email
can
be
solved
by
providing
the
emulator
station
and
an
alternate
challenge.
Okay,.
H
H
H
H
Sorry,
just
the
last
bit
just
comparing
them
in
to
what
James
Brown
said
in
a
way
that's
similar
or
in
competition
with
how
quarter
is
doing
it
like
they're,
showing
ways
to
do
it
all
applications
of
that
and
we
want
to
do.
We
want
to
serve
the
same
market,
and
so
will
we're
designing
this
to
do
the
similar
things
you.
B
Can
describe
because
such
but
I'm
a
member
of
called
a
global
occupied
working
group
and
the
person
involved
in
creating
an
altar
like
coda
in
the
first
place,
so
you
can
also
say
that
I
took
what
I
did
the
design
principles
are
applied
in
this
example
and
reapplied
in
business
or
setback.
It
doesn't
have
to
be
that,
because
code
I
decide
is
designed
it
like
this.
We
have
to
do
that.
Part
of
it
is
designed
by
me
too
yeah.
H
B
Level
we
wish
developers
to
look
at
how
attestation
is
used
to
to
have
a
process
and
then
come
up
with
their
own
attestation
and
on
a
higher
level.
We
are
solving
the
tokenization
business.
We
provide
we're
talking
addition
happen
and
the
test
station
is
needed
for
tokenization
is
something
already
learned:
I
don't
have
to
go,
go
back
and
prove
it
a
game.
Then
yeah
doesn't
exist.
This
I
understand
toka
script
has
competition,
but
attestation
has
no
competition.
Their
idea
is
tokenization
doesn't
have
to
be
done.
Bite
of
the
script.
B
B
D
B
H
That's
not
what
I'm
trying
to
do
now,
but
I
I
understand
that
yeah.
We
tokens
group
who
need
attestations,
and
this
contrived
example
is
just
to
implement
attestations
with
an
with
yet
contrived
example
with
that
his
email,
even
though
it
might
not
be
the
most
practical
example.
My
understanding
is
that
it's
just
a
example
to
show
it
to
stations.
B
H
C
C
C
C
H
So
attesting
to
having
possession
of
oh
yeah,
so
some
authority-
that's
it
that's
actually
good
distinction,
boon
to
say
it's
not
comms
channel
but
yeah.
So
if
it's
social
security
number
I
go
to
my
centralized
authority
that
will
provide
an
attestation
that
I
can
use
and
not
reveal
it
in
transactions.
Yes,.
B
G
G
G
D
B
H
Now
I
think
yeah
that
that's
a
again
good
distinction,
boon
and
yeah.
It's
I
guess
going
back
to
the
initial
assumptions
we're
saying
yet
there
is
a
SATA
station
Authority
for
data
X,
whatever
it
may
be,
but
the
practical
use
cases
that
exists,
as
you
know,
as
like
your
experience
way,
which
says
it
makes
business
sense
that
there
are
you
know
whatever
business
it
is,
will
provide
an
attestation
for
a
fact
and
then
tokenization
says
other
people
want
to
use
those
data
stations
to
do
things.
That's
I
mean
just
to
give
the
abstract.
B
H
B
It
just
occurs
yeah,
so
so
we
do.
We
do
use
blockchain
to
change
our
business,
but
are
we
going
to
change
into
the
core
part?
How
business
recognize
things
I'm,
not
sure
if
that
is
that
people
change
we're
just
adapting
better
part
of
business
and
the
hesitation
model
is
not
a
case
decentralization
either
and
it
actually
centrality
centralizes
the
tester
as
well
yeah.
That's.
E
Go
for
this
bar
is
not
thermal,
create
a
station
to
developers
or
others.
They'll
go
for
to
you,
email
messages
to
push
ourselves
to
normalization
little
bit
further,
because
otherwise
the
disease
was
just
something
we
have
been
talking
for
years
and
never
been
implemented,
and
at
least
is
the
email.
High
station
say
is
a
little
feet.
If
it's,
if
it
works,
then
it
is
a
feature
which
all
the
business
everyone
knows
who
all
the
only
normal
users
can
be
benefit
from.
E
E
F
E
But
why
we
choose
to
go
through
like
a
more
difficult
way,
as
I
mentioned,
because
this
attestation
thing
is
useful
and
we
already
know
it,
so
we
need
to
start
implement
head.
So
everyone,
since
there's
a
very
useful
feature,
can
use
this
technology.
Then
we
we
use
it
to
the
implementation
of
this
technology.