►
Description
This is the 6th Episode of our 'Whiteboard Series with NEAR' where we had Rongjian Lan (https://twitter.com/RongjianLan) from Harmony (https://twitter.com/harmonyprotocol) speaking with our Co-Founder Alex Skidanov (https://twitter.com/AlexSkidanov)
Learn more about Harmony here: https://harmony.one/
Download the video here: https://near.ai/0e871
------- About Whiteboard Series ---------
The Whiteboard Series with NEAR is a set of video interviews with Founders who are building scalable solutions for Blockchain. We deep dive into their story, what they're developing and how it is helping the ecosystem.
Follow the latest from NEAR Protocol on,
Discord: https://near.ai/discord
Medium: https://near.ai/medium
Twitter: https://near.ai/twitter
GitHub: https://near.ai/github
A
Hi
everyone-
this
is
alex
from
near
protocol,
we're
in
Cupertino
at
Harmony
office
with
me
today
is
r.j.
one
of
the
developers
of
harmony
and
we're
going
to
go
into
very
deep
technical
details
of
harmony
protocol
today,
RJ.
Would
you
like
to
quickly
introduce
yourself
and
give
us
an
overview
of
how
harmony
works?
Okay,
hi.
B
Everyone
I'm
RJ
from
harmony,
I'm,
the
core
developer
and
co-founder
of
harmony.
How
many
is
a
high-performance
blockchain
that
features
sharding
and
secure
proof
of
stake,
and
our
consensus
is
a
fast
pbft
consensus
I
also
like
improve
on
the
network
infrastructure,
so
that
the
Chardon
network
can
operate
in
a
special
way.
You.
B
B
So
the
shark
chain
will
process
transactions
separately,
so
each
chart
has
its
own
stage
right.
So
for
the
for
the
head
of
the
block,
they
contain
the
states
of
the
shark,
so
harmonies
stay
sharding,
which
means
the
state
of
the
parties.
They
are
separated
and
stored
separately
in
shark,
that
those
states
are
different,
contain
different
data
and
the
for
each
chart
is
separately
process
transactions
in
parallel.
So
let's
say
you
have
a
transaction
here,
and
this
transaction
is
specifically
for
this
chart
one.
B
C
B
Another
is
storing
the
cross
link
from
the
other
shark
howling
from
the
other
shark.
So
for
the
randomness,
the
begin
chain
need
to
use
is
to
run
distributed.
Randomness
a
generation
protocol
to
generate
this
secure,
randomness,
that's
unpredictable
impossible
and
like
verifiable,
so
that
it's
hard
for
people
to
like
bias.
This
randomness
or,
like
many
of
you,
know,
randomness,
because
the
randomness
is
important
in
the
sharding
process.
B
Why
is
it
is
important
because
we
wanna
randomly
assign
the
validators
to
each
shark
so
that
the
attack
the
attacker
won't
concentrate
there
like
voting
power
inside
a
single
shard,
so
that
required
this
secure
randomness
another
function
for
beacon
chain
is
the
cross
link
to
the
other
shark.
So
for
each
of
the
Block
in
the
char
that's
generated,
you
will
sent
the
header
to
some
of
the
blocks
in
the
in
the
in
the
shark
chain
in
the
beacon
change,
sir.
B
So
with
this,
we
can
have
a
global
kind
of
global
ground
truth
for
which
chain
in
the
shark-
that's
that's
canonical
and
also
for
the
beacon
chain
to
contain
all
of
the
headers
of
the
shark
chain.
You
can,
you
can
directly
broadcast
or
sync
those
headers
to
the
other
shark,
so
the
other
shark,
either
like
a
header
chain
of
or
the
other
shark,
so
that
they
can
act
as
like
a
light
client
for
the
other
shark
so
that
they
can
verify
some
some
of
the
proofs
from
other
shark.
B
B
A
A
B
The
cross
link
will
make
sure,
there's
a
one
canonical
like
truth
about
which
shark
should
be,
which
chain
right,
because
there's
a
cases
where
one
chart
like
half
works.
You
you
it's
hard
to
like
figure
out
which
shark
is
which
which
change
the
canonical,
because
we're
now
using
a
Perl
work.
Where
is
in
pbft,
so
and
also
we're
using
staking
to
prevent
a
civil
attack.
B
So
it
will
be
a
little
bit
easier
than
pro
work
to
have
to
have
to
create
Forks
and
that's
kind
of
hard
to
distinguish
from
the
canonical
one
with
the
cross
link,
because
the
you
can
change
like
a
century
is
like
the
globo
ground
truth
and
that
also
beacon
chain
has
more
security.
So
it's
more
trustful.
So
if
you
put
the
hash
link
from
char
chain
to
the
beacon
chain,
we
have
a
better
security,
you're,
more
kind
of
proof
that
a
single
change,
the
canonical
one
yeah,
but.
B
A
For
as
long
as
one-third
of
the
stake
is
for
as
long
as
less
than
one-third
of
the
stake
belongs
to
people
who
are
intentionally
trying
to
behave
maliciously,
the
fork
is
impossible
right.
Yes,
so
so,
if
actually,
the
design
of
the
system
assumes
that
it
is
possible
to
have
more
than
one-third
of
malicious
actors
in
the
short
chain.
So
the
question
is.
A
A
C
B
The
global
pool
validator
so
when
they're
doing
staking,
we
have
this
adaptive
to
actually
POS
staking,
which
is
working
like
this
I'll
join
here
so
like.
So
simply,
we
have
three
meditators
that
has
different
amount
of
stake,
so
this
day
and
I
wondered
one
road,
token
stick
and
this
have
like
50
tokens
nicked,
and
this
one
have
like
20
tokens
staked
and
after
this
take
this
amount
of
token
we'll
use
the
formula
two
formulas
like
this.
This
formula
is
for
the
price
for
a
single
like
ticket.
We
call
them
voting
share.
B
B
Right
here,
if
we
want
to
make
the
shark
secure
after
the
random
random
charting,
we
need
to
make
the
security
parameter
largely
enough,
so
we
calculated
it
has
to
be
600
so
that
when
the
process
is
like
this
after
they
do
staking
they
based
on
these
pranks,
the
game
voting
shares.
Let's
say
we
have
600.
Let's
say
this:
lambda
is
600
and
the
each
is
voting.
Shares
surprises
like
let's
see
600.
C
C
B
A
B
So
we'll
randomly
distribute
these
voting
shares
into
the
number
of
shirts.
So
if
we
have
like
10
yards,
this
water
shares
will
be
randomly
distributed
or
to
these
sharks
so
and
the
end
result
is
for
each
chart.
This
first
validator
will
have
some
amount
of
water
insurance
there,
because
it's
randomly,
you
will
be
in
expectation.
It
will
be
proportional
to
their
original
staking
right.
So
here,
let's
say
here:
this
one
I
have
like
400
what
each
are
here
for
the
linear
one
and
here
is
like
380,
but
in
follow
well
either
one
something
like
this.
A
If
you're
making
so
with
your
particular
constants
right,
let's
say
that
the
assumptions
about
malicious
actors
in
the
global
pool
is
a
25%
and
I
say
the
security
parameter
is
actually
600.
Then
the
probability
of
having
33%
of
malicious
actors
is
practically
zero
right.
It's
it's
like
1,
minus
18
or
something
so
why
do
we
need
to
cross
link
if
it's
like
it
seems
like
working
is
impossible?
A
B
A
C
A
B
Okay
yeah,
so,
as
I
said,
the
shardene
need
to
first
distribute
at
the
distribution
of
the
validator
need
to
be
done
securely,
but
also
we
need
to
take
care
of
the
corrupt
corruption,
of
a
single
char
right,
where
we
have
this
restarting
mechanism,
which
means
pure
article
e,
we're
going
to
reshuffle
the
validators
in
the
shark
or
their
voting
power
in
the
charts
across
different
shards
right.
So
when
attacker
corrupt,
a
single
shark,
you
will
not
like
be
able
to
get
the
whole
shards
voting
power.
B
How
to
say
like
for
a
long
time,
because
we're
gonna
reshuffle
the
voting
power
again
and
again.
So
that
is
it's
always
they
had
to
keep
catching
up
with
the
reshuffle.
So
we're
gonna
keep
the
reshuffle
frequency
high
enough,
so
that
we're
a
hyper
with
high
probability
that
attackers
can
knock
cannot
be
easily
overtaking
a
single
shark
yeah.
A
But
we
do
believe
that
they
can
take
over
the
single
shark
for
a
very
brief
period
of
time,
all
right.
So
let's
go
to
the
standard
attacks
on
the
shore,
so
the
easiest
one
is
forking
right
and
so
against
working
we
protect
by
cross-linking
now
the
the
bigger
chain
when
it
snapshots
the
short
chains,
effectively
beacon
chain
acts
as
a
light.
Client
right,
so
they
can
chain
does.
Is
it
gets
the
header
as
Jim
began
chain,
doesn't
unload
the
entire
block
right?
That
would
be
lots
of
information
to
them
load
right.
A
So
let's
say
that
two-thirds
of
people
were
corrupted
in
a
single
shard
right
and
let's
say
that
what
they
did
is
they
created
the
block
and
in
this
block
the
state-transition
function
is
a
plate
in
a
completely
wrong
way.
Right
so
like
out
of
nowhere.
One
of
the
malicious
actors
gets
1,000,
for
example,
and
on
top
of
that,
not
necessarily-
but
let's
say
they
also
built
another
block
which
otherwise
is
valid
so
like
from
this
from
the
state
that
was
passed
from
this
block
to
the
state.
A
That
was
final,
that
the
state
transition
was
applied
properly
and
now
this
block
is
being
snapchatted
or
like
I
guess
both
of
them
get
snapchatted
to
the
beacon
chain.
The
beacon
chain
has
no
way
to
detect
right
that
the
block
was
wrong.
So
so
what
is
the
like?
I
was
assuming
that
that
cannot
happen
or
how
to?
How
do
we
defend
against
this?
So.
C
B
A
Right,
but
that
is
from
perspective
of
something
right
so
simply
if
sampling
1/3
is
very
close
to
zero
sampling,
2/3
will
be
practically
zero,
but
if
we
think
that
is
an
adduct
adaptive
adversary,
then
it
seems
like
if
we
believe
that
adaptive
adversary
can
corrupt
1/3.
It
seems
to
be
reasonable
to
assume
that
they
can
also
occur
up
2/3
like
then,
there
is
no
exponential
decay
and
probabilities.
That
does
make
sense.
B
Yeah
viewpoint
so
like
we
try
to
make
the
restarting
process
frequent
so
that
we're
gonna
make
sure
that
it's
almost
impossible
to
create
works
that
create
to
create
wrong
state
because
also
we're
using
the
we
have
pbft
or
be
empty.
Consensus,
which
is
by
nature,
is,
is
hard
to
create
works
and
they
also
provide
finality
faster.
C
A
B
Just
as
I
said,
all
the
picking
chain
or
chargee
are
just
like
a
shark.
It's
the
sharding
process
or
restarting
process
apply
to
all
of
them.
So
it's
just
a
matter
of
how
much
like
steak
or
voting
power
you're
going
to
assign
to
them
right.
So
as
I
already
analyzed,
the
security
of
a
single
char
is
already
kind
of
proved
secure
right.
So
for
the
search
for
the
we
can
change
this.
It
has
the
same
security
as
the
char
chain
if
we
treat
them
as
the
same
shard
as
the
other
shark.
B
That
basically
means
putting
the
same
amount
of
voting
power
or
staking
into
them,
but
we're
gonna.
Since
the
you
can
change
the
like
the
global,
it
can
be
the
single
point
of
failure,
so
we're
gonna
put
a
sign
more
staking
effectively
lambda
Square
so
say:
let's
say
each
char
has
the
equal
amount
of
voting
show
or
taking
that's
assigned
to
them.
We're
gonna
assign
like
two
times
of
the
staking
to
to
the
beacon
beacon
chain.
So
that
is
like
a
lot
more
secure.
C
A
A
B
This
is
actually
a
very
simple,
so
if
I
want
to
send
some
money
from
the
shark,
a
shark
shark,
one
to
Sharpie
I
just
create
a
transaction
specifying
the
source
money
source
account
is
share,
one
some
some
account
of
yours
and
then
destination
account
in
char
to
some
other
account
other
person's
account,
and
then
the
transaction
will
be.
They
say
this.
The
crosswalk
reflection
will
be
sent
to
the
source
shark
right
and
the
source
chart
will
first
like
kind
of
debit.
B
The
term
money,
you're
gonna,
spend
right
so
you're,
gonna,
first
cut
like
deduce
your
balance
first
and
then
generate
proof
in
the
form
of
like
a
receipt
like
a
serum
receipt,
the
sender's
proof
to
the
destination
shark.
So
there's
an
initial
shark
as
I
said
destination
chart
will
act
as
a
light
client
of
the
other
chart
right.
So
you
can
check
that
proof
is
valid
and
also
based
on
the
cross
link.
All
those
stuff.
You
can
make
sure
that
that
money
early
data
is
detected
and
then
the
char
two
is
safe
too.
A
I
presume
that
Carmen
is
also
executing
smart
contracts
right
when
I'm
sending
a
so
let's
say,
I
have
a
crypto
zombies
account
on
this
short
kazoos
on
this
contract
and
here's
a
cryptic
Aegis
contract
on
this
chart
and
I
have
a
I
want
to
have
a
method
encrypted
zombies
which
would
consume
a
cryptic
e
key
to
do
something
right.
So
how
would
that,
as
a
developer,
how
do
we
express
the
the
cross
chart
in
vacations?
Is
it
some
sort
of
like
promises
or
like
how
does
that
work?
So.
B
B
We
had
this
mechanism
of
kind
of
like
code,
it's
not
it's
more
like
subscribe
and
listen
right.
So
let's
say
your
smart
contract
won't
we'll
be
reading
some
fields
in
the
other
shards
of
our
contract,
and
you
are
gonna
like
specify
that
in
the
smart
contract
and
then
be
the
data
that
you're
gonna.
Listen
in
the
in
the
in
this
chart.
Those
validator
in
that
shirt
whoa
like
publish
that
part
of
the
data
you're
interested
to
your
shark
right
in
the
keep
publishing
that
it's.
B
A
But
I
I
can
do
right
operations
for
the
contracts
which,
on
the
same
charges,
I
write
you
can
you
can
write,
then
the
question
is,
you
said
it
at
the
beginning
is
going
to
be,
let's
say,
10
charts,
but
then
over
time,
I
assume
you
want
to
go
that
to
thousands
of
shirts.
When
you
increase
number
of
thirds
the
new
charts
are
the
empty
or
you
rebalance
it
will
be
created.
A
new
are
they're
going
to
completely
empty,
so
the
people
I
guess
that
would
work,
I,
guess,
cool
okay.
So
let's
move
to
the
consensus.
C
B
There
is
a
face
or
prepare
right
and
another
face
go
commit
and
before
that
the
leader
will
announce
the
like
a
block
first
to
all
the
validator.
This
we
call
the
announce
face
so
once
the
leader
announce
the
new
block
to
the
validator,
the
very
very
first
check,
whether
is
valid
or
not
right,
and
then
they
will
sign
the
POS
signature
on
the
on
the
header
and
return
back
to
sorry.
B
And
then
the
same
thing
kind
of
same
thing
happened:
all
the
validator
need
to
check
this
month,
whether
they're
more
than
like
two
to
at
plus
one
where
F
is
the.
What
above
is
a
one
third
of
the
committee,
whether
there
are
more
than
2/3,
plus
one
or
equal
to
2/3,
plus
one
signing
on
that
motor
signature.
A
It
synchronous
or
is
it
weekly
synchronous,
it's
partially
synchronous,
partial
synchronous.
So
well,
when
does
part
so
there's
some
sort
of
a
timeout
here
right.
So
at
some
point
like
clearly,
there's
not
never
going
to
be
the
case
that
the
leader
will
accumulate
all
the
signatures
or,
like
it's
gonna,
be
very
rare.
Someone
will
be
applying
right.
You
have
600
validators.
Presumably
someone
is
offline,
so
at
which
point
leader
stops
waiting
for
more
signatures
and
and
start
distributing
the
block
once
they
have
to.
B
A
A
You're
right
but
that,
but
then
the
leader
only
wait
for
2/3
plus
1.
Let's
say
100%
people
are
online,
that's
everybody's
online,
but
the
moment
the
leader
gets
two
thirds
plus
one.
They
already
descend
the
block
right.
So
two
thirds
like
F
people.
If
people
did
not
get
their
signatures
into
the
block,
so
the
block
is
recorded
only
having
two
thirds
plus
one
signatures,
so
f
people
who
were
online
and
participated.
You
know
it
will
not
get
to
avoid
right.
Yes,
isn't
that
unfortunate.
B
No,
no
because
you
have
to
wait
for
exact
this
amount
to
like
proceed.
You
can
not
wait
more
because
the
security
assumption
is
we
we
can
have
at
most
or
or
it's
possible
to
have
F
malicious
nodes
right.
So
if
you
wait
more
there,
you
are
busy
waiting
for
at
least
one
malicious
guide,
then
tacca,
if
that
guy
is
stalling,
you'll
never
get
yes,.
A
Not
that,
but
my
question
is
more
about
the
fact
that,
like
let's
say
that
v1
and
v2
signed-
and
so
the
leader
progressed
but
v3
now
we
T
will
not
get
any
word
right.
I
said
every
every
everyone
will
give
even
people
who
wore
a
fine
yeah,
but
then
we
get
back
to
the
question.
Why
would
I?
Why
would
be
three
even
be
online
yeah.
A
A
B
A
good
question,
then
this
will
come
to
the
like
filtering
problem
right.
The
leader
have
the
power
to
filter
anything
they
don't
like.
So
in
that
case,
the
the
nodes
were
really
deter.
Who
got
filtered
can
show
that
some
of
some
proof
that
he
already
signed
that
for
a
long
time
for
many
realms,
but.
A
A
B
B
A
B
C
B
A
Tradition
pbft,
the
the
person
who
is
proposing
a
new
leader
at
some
point
needs
to
communicate
and
cubed
amount
of
information
for
600.
That's
almost
a
gigabyte
of
information
right.
It
needs
to
be
communicated
like
effectively
in
traditional
pbft,
the
the
leader
change.
The
view
change
is
accumulating,
like
every
person
will
send
some
proof
that
the
consensus
wasn't
reached
to
their
to
the
new
to
the
candidate
can
get
the
candidate
leader
and
the
candidate
leader
needs
to
send
all
those
proofs
to
all
the
validators
right.
A
B
C
A
That
doesn't
work,
because
what
will
happen
is
what
will
happen
is
that
these
are
reason
when
TB
of
GD
is
a
quadratic
proof.
The
quadratic
proof
that
that
you
need
to
send
is
you
need
to.
You
need
to
confirm
that
everybody
is
on
the
same
page
that
we're
doing
a
leader
change,
because
otherwise,
what
will
happen
is
that
every
validator
will
send
like
the
leader
will
be
acting
normally
up
until
this
point.
At
this
point,
everybody
will
send
to
the
leader
their
signature
parts.
A
At
this
point,
the
leader
has
the
block,
and
this
block
has
the
has
the
has
a
consensus
on
it
like
this
block
is
the
reversible,
but
the
leader
doesn't
broadcast
the
block,
so
the
leader
knows
the
block.
Nobody
else
does,
and
so
by
this
time
by
the
time
when
the
commit
is
supposed
to
happen,
every
validator
says:
well,
consensus
isn't
reached
the
block,
wasn't
broadcasted,
and
so
it
could
happen
that
2/3
of
them
will
message
the
candidate
leader
saying.
A
We
think
that
the
consensus
has
told
has
told
the
candidate
leader
will
say:
I
see
2/3
of
people
thinking
consensus
told
they
will
do
their
own
consensus.
Come
up
with
some
other
block
at
which
point
old
leader
will
broadcast
their
now.
You
have
two
blocks,
each
of
them
having
two-thirds
plus
one
signatures.
That's
a
it's
a
it's
a
fault
right!
So
that's
not
to
pbft
consensus.
I
mean
that's
not
to
BFD
consensus.
Then
the
BFG
consensus
guarantees
that
you
will
never
have
two
blocks
with
two-thirds
plus
one
signatures.
That's
make
sense,
so
I,
don't.
A
Once
again,
so
this
is
the
current
winner
he's
malicious
he's,
acting
normally
up
until
this
moment,
so
they
do
broadcast
the
block.
They
accumulate
the
first
set
of
signatures
they
broadcast
the
science.
Signature
accumulate
two
thirds
of
signatures
here.
At
this
point
they
have
a
block
with
two
thirds
of
signatures.
That
block
is
final,
but
they
do
not
broadcast
the
block.
C
A
What
you
described
so
this
is
the
first
block.
This
is
the
first
finalized
book,
but
they
do
not
broadcast
it.
So
if
I
understand
correctly
how
you
do
view
change,
then
at
some
point
of
time
the
timeout
will
be
hit,
at
which
point
all
the
validators
will
think
that
the
consensus
stopped
and
so
all
the
validators
ten
minus
one
will
reach
out
to
some
other
candidate
leader
and
say
we
want
to
kick
out
the
existing
leader.
They
act
him
slowly
and
start
a
new
consensus.
All.
B
A
B
A
C
A
C
A
C
A
Do
we
even
need
any
any
sort
of
DFT
consensus?
Can
we
just
say
that
the
crosslink
always
has
a
like?
Why
not
send
block
at
this
point
right
it
we
got
to
this
point.
We
send
the
block
to
the
beacon
chain,
if
beacon
chain
confirm
that
we
say
yeah,
that's
final,
and
then
we
saving
a
full
round
of
communication
right.
B
A
B
A
Point
of
temperament
is
that
is,
yes,
is
that
the
leader
is
proposing.
It's
super.
Similar
I
did
leaders
proposing
the
block
accumulating
signatures
accumulating
signatures,
but
there
are
timeout
after
every
step
and
I've
acted
this
step.
The
consensus
isn't
reached.
The
the
next
leader
starts
starts
the
castell
the
next,
that
there
is
proposing
the
block
and
they
have
certain
guarantees
that
will
not
allow
two
blocks
being
produced,
but
the
view
change
is
gone
right
and
without
the
view,
change
it's.
It's
super
cheap,
alright,
yeah,
okay,
I
guess,
consensus
makes
sense
the
with
the
consensus.
A
B
That's
the
test,
the
filtering
question
right
so
for
the
transaction
insurer
you
should
be
able
to
like,
because
it's
broadcasted
to
the
network,
every
other
validator
will
see
that
whether
there
is
a
transaction
or
not
and
if
issuer
found
that
each
transaction
did
not
get
included
for
a
long
time
were
people
see
that
the
leader
is
producing
and
people
out
for
a
long
time,
then
the
movie
will
have
some
criterias
to
say
at
this
point,
everybody
everybody
should
change.
The
leader
is.
B
A
But
what
if?
Let's
say
that
the
system
is
at
capacity
like
the
shard
is
at
capacity?
It
cannot
include
all
the
transactions.
Isn't
that
the
problem
that
the
leader
has
the
sole
power
to
choose
which
transactions
get
in
and
which
transactions
do
not
like?
Okay,
you
can
prove
that
your
transaction
was
not
included,
but
the
leader
has
an
excuse.
The
leader
says
the
block
was
full
right,
and
so
now
the
wither
can
censor
out
any
transactions
without
any
penalty
right,
yeah.
C
B
A
Another
question
is:
how
is
this
timeout
chosen
right?
So
let's
say
that
the
for
some
reason,
network
conditioning
became
worse
and-
and
we
just
like-
let's
say
timeout
was
five
seconds
and
let's
say
that
the
network
condition
conditions
became
worse
like,
for
example,
the
validators
were
chosen
in
such
a
way
that
a
large
portion
of
them
like
distributed
in
the
world
or
like
let's
say
that,
like
the
cross
option,
link
had
broken
or
sampling
that
look
nuclear
winter.
B
B
A
But
the
question
so
let's
say
there
was
a
leader
who
who
had
a
ridiculously
good
network
or
even
better
here's
an
example.
Let's
say
that
yeah.
So
let's
say
there
is
a
leader
who
has
very
good
network
and
very
good
processing
power,
and
so
that
can
execute
consensus
very
quickly,
mm-hmm
to
an
extent
it
like
they
finalized.
The
full
consensus
is,
let's
say,
0.3
seconds,
but
let's
say
that
the
majority
of
people
have
worse
hardware,
and
so
let's
say
for
them.
It
takes
like
a
second
and.
C
A
Leader
so
let's
say
this
leader
produce
multiple
epochs
in
every
epoch.
Consensus
was
reached
in
like
0.3
seconds
and
then
they
stood.
There
goes
the
flame,
and
so
my
understanding
is
that
the
timeout
will
be
let's
say,
0.5
seconds
right,
but
then
no
leader
will
be
able
to
produce
a
block
in
0.5
seconds.
So.
B
A
A
Actually,
one
thing
about
pbft
is
that
they
prove
like
why
the
proof
is
expensive.
Is
that
I
think
every
unless
I?
Remember
it
wrong?
I
think
it's
because
every
validator
needs
to
prove
to
the
candidate
that
they
saw
majority
of
validators
wanting
to
switch
and
I
think
that
can
be
optimized
with
their
less
signatures.
Yes
and
then,
and
then
it
will
be
quadratic,
which
is
like
way
more
doable.
Okay,
so
randomness
you
guys
using
the
run
dial
with
videos
right.
It's.
B
Not
render
yeah,
it's
not
exactly
a
render,
you
can,
can
you
walk
us
through?
They
are
yeah
and
say
this
is
the
start
of
the
new
year
POC
and
at
the
start
of
the
new
year
Park
the
leader
will
like
pull
from
all
the
validators.
They
say
this
all
the
validators
and
tell
them
hey
that
were
starting
the
randomness
protocol
and
it
was
saying
it
will
send,
send
the
like
previous
block
hash.
They
say
this
wonders
and
yes,
the
leader
will
send.
Let
us
say
this:
is
the
leader
either
announced?
B
B
We
call
preimage
of
randomness
and
then
run
consensus.
That's
a
kind
of
same
pbft
consensus
just
just
include
that
in
the
next
walk
right
and
with
all
the
proofs
of
the
VRI
proofs,
so
that
this
get
committed
to
this
block
and
then
the
because
it's
in
the
block,
everybody
is
free
or
the
leader
can
just
compute
using
video
I'll
verify
about
delay
function
right
is
probably
I
can
show
that
you
spend
some
time
to
compute.
B
A
C
B
Doesn't
have
to
be
that
large
say
this
is
in
K
block
something
somewhere
around
the
n
plus
K
block
you,
you
get
the
true
randomness
and
then
you
commit
that
you
run
consensus
again
with
all
the
proofs,
and
people
will
verify
that
right
and
will
confirm
over
sign
and
you
can
commit
it
to
the
block.
So
right
here
you
get
the
randomness
or
all
the
way,
all
the
sharding
or
anything.
The.
A
Question
is:
did
you
guys
think
which
particularly
do
you
have
to
use,
will
probably
go
with
the
assumed
one
yeah
right,
so
so,
with
the
theorems
PVDF,
they
build
an
a
secret
which
is
going
to
be
give
or
take
hundred
times
faster
than
than
anything.
You
could
have
like
traditional
hardware.
So
if
the
expectation
that
the
leader
has
to
have
the
ASIC,
no,
no,
we.
B
A
That
means
that
the
key
needs
to
be
well
at
the
very
least
more
than
100
trade
yeah
because
of
the
ASIC
is
hundred
times
faster
than
traditional
hardware,
but
also
ASIC
basic
is
hundred
times
faster
than
very
good
hardware
right.
So,
if
you're
running
on
regular-
like
that,
you
don't
have
you
don't
have
a
super
strong
hardware,
it's
going
to
do,
but
the
bigger
problem
is
in
the
theorems
case,
because
that's
a
they
use
exactly
the
same
approach
right.
They
have
I'm,
not
sure
about
like
the
signature,
but
they
have
pre
commits
from
multiple
people.
A
Then
they
compute,
the
vdf
and
the
output
of
the
vdf
is
Vidya
from
the
aggregate
of
the
pre
commits
and
the
output
of
the
VD
occurs
randomness
in
the
theorems
case.
It
is
the
expectation
that
the
vdf
is
going
to
be
run
by
a
person
with
a
magic
right,
so
it
is
not
expected
that
anyone
will
run
ggf
Isaac
as
a
result.
A
For
someone
to,
and
let's
say,
K
is
a
hundred
right
as
a
result
for
someone
to
build
faster,
they
will
need
to
have
an
even
faster
Isaac
right
and
the
ASIC
that
the
theorem
is
building
cost
fifteen
million
dollars
to
build
so
from
to
build
even
faster
Isaac.
It
will
cost
like,
given
more
and
and
like
how
much
how
much
faster
is
going
to
be
like
you
need
two
hundred
times
faster,
which
is
barely
impossible
in
this
case.
A
The
problem
is
that
lets
say
the
harmony
becomes
d
protocol
right,
so
someone
actually
has
a
very
strong
incentive
to
break
it.
So
if
K
is
configured
to
be,
let's
say
two
hundred
right,
you're
saying
you
know,
look
at
the
video
music
is
kind
of
times
faster,
we're
going
to
configure
K
to
be
two
hundred.
A
No
there's
no
way
that,
if
they
do
magic
is
going
to
be
this
now
for
someone
who
wants
to
break
the
randomness
for
them,
the
cost
is
going
to
be
building
an
ASIC,
which
is
three
hundred
times
faster,
which
is
that's
expensive,
but
you
know
like
we're
talking
about,
like
whichever
protocol
is
going
to
be
the
protocol,
we're
talking
about
like
hundred
billion
dollars,
protocols
right.
So
what
what
is
fifty
million
invested
right?
A
B
Haven't
decided
that
yet
because
you
don't
have
like
a
like
a
defined
like
a
period
for
the
for
when
you're
gonna
get
the
redness
right,
so
you
may
not
get
randomness
for
each
block.
So
there's
a
question
we're
still
researching,
but
this
is
definitely
used
for
the
other
network
charting
yeah,
because
this
is
only
happening.
Every
epoch,
mm-hmm.
A
A
B
A
1/4
has
a
theoretical
chance
to
creative
work,
because
what
you
can
do
is
you
can
all
it's
not
it
I
will
provide
the
theoretical
what
you
can
do
in
theory
in
practice,
it's
hard
but
like
it
gives
you
the
theoretical
ability
effectively.
What
you
can
do
is
you
can.
This
is
like
slightly
less
than
one
third
of
one
as
validators.
This
is
slightly
less
than
one
third
of
one
is
validators,
and
this
is
your
slightly
more
than
one
third
of
malicious
validators.
You
can.
A
Yeah
and
then
you
know
yeah,
this
is
not
practical,
because
you
cannot
really
split
the
network,
but
it
gives
you,
like.
You
know
like
a
2/3,
you
can
definitely
spork
at
one-third
below
one
heard.
You
definitely
cannot
fork
but
exactly
how
it
grows
from
zero
to
one
in
between.
We
don't
know
right,
but
let's
say
we
believe
that
four
can
happen
all
right,
because
I
mean
we
cross
link.
They
share
fight
that
we
cross
link
effectively
means
that
we
delete
the
four
can
happen
right
then.
A
That
means
that
the
big
and
chain
can
fork
right,
because
the
big
can
chain
has
only
twice
as
many
validators,
so
it
is
also
feasible
to
corrupt
them.
Adaptively
so
put
the
following
happen:
could
it
be
that
I
have
I
mean
one
Charlotte?
This
is
hard
one
and
it's
building
in
the
blockchain,
and
this
is
short,
can
I.
Do
this
like,
let's
say
my
adaptive
adversary
that
is
capable
of
working
mm-hm,
then
what
I
can
do
is
I
can
create
a
block
here.
C
A
Which
I
send
money
to
the
merchants,
I
create
a
block
on
the
beacon
chain
or
it
get
cross-linked
and
and
some
merchants
lease
use
mine
over
here
right
and
the
merchants
receiving
money
here
provides
me
the
service,
but
after
that
I'm
working
here-
and
this
happens
to
be
the
canonical
channel.
I
am
14
here,
and
this
happens
to
be
a
canonical.
What
happens?
Is
we
have
a
double
spent
rate
because
this
like
in
this
chart?
There
is
no
reason
for
this,
not
to
state
the
canonical
chain.
B
A
Right,
the
only
concern
is
that
so
the
question
is
how
much
more
stake
you
put
on
the
big
engine.
If
it's
twice
as
much
and
we
talking
about
gonna,
die
to
adaptive
adversary,
then
the
attack
is
only
three
times
more
expensive,
because
if
it,
if
it
costs
X
to
corrupt
this
short
that
goes
to
X
to
crop
discharge,
I'd
like
that,
has
to
be
exactly.
B
A
C
B
C
B
Of
the
neighbor
will
gossip
again
to
the
other
neighbor,
so
this
will
incur
like
so
you
have
D
neighbor
people
have
like
M,
plus
D
Network
consumption
on
the
standard
right.
So
when
the
block
is
large,
say
like
a
megabyte
of
the
part
of
the
block
so
Doby
have
you
be
a
bottleneck
for
the
sender,
so
what
we
did
is
we
are
using
the
user
coding.
B
B
It's
missing
some
of
them
right,
it's
the
same
because
right
here
is
sending
the
hop
lock,
so
this
guy
already
have
the
block
he
doesn't
need
to
sign,
but
here
is,
is
sending
the
chunks
right
each
each
others
are
different.
So
this
is
the
first
and
they
also
need
to
like
communicate
to
get
like
a
full
picture.
Yeah.
B
A
B
Code
is
a
jerk.
The
traditional
user
code
is
based
on
the
resettlement
encoding,
which
is
a
fixed
encoding
say
you
can
only
add,
like
the
sale
is
a
fixed
point
or
say
30%
of,
and
if
is
in
the
rare
case,
that's
not
like
kind
of
enough.
Then
some
node
won't
get
the
reconstructed
block.
So
instead
we're
using
the
fountain
Raptor
cue
fountain
code
code,
which
is
more
like
a
continuous
adaptive
encoding.