►
From YouTube: Hyperledger Seattle Meetup - June 19, 2018
Description
Video from the June 19 Hyperledger Seattle Meetup hosted by Rich Bloch, "A Survey of Consensus Models in Hyperledger." The presentation is about the heart of all blockchain platforms: consensus algorithms. We covered the fundamentals of consensus algorithms, the different Hyperledger projects, and the consensus algorithms that support them. Hyperledger projects covered included Hyperledger Fabric, Indy, Iroha, and Sawtooth.
You can join the group here: https://www.meetup.com/Hyperledger-Seattle-Chapter/
----
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
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 #HyperledgerMeetups #Blockchain
A
All
right:
well
now,
we've
got
our
guest
speaker
here,
Mabel
OSA,
to
present
an
introduction
to
D
central.
No,
that's
not
right!
My
notes
are
wrong.
There,
you
go
hyper
ledger
consensus.
All
groups,
I,
don't
know
what
he
did
so
I'm
able
is
a
marketer
turned
engineer
who
is
in
space,
insatiable
drive
to
simplify
life's
complexities.
Her
love
for
blockchain
started
when
she
attended
a
Steve
Wozniak
event
and
the
attendee
next
to
her
gave
her
a
ten
dollar
coin
in
Bitcoin.
A
Foolishly,
she
lost
her
passcode,
who
this
is.
This
is
endemic
in
an
attempt
to
recover
the
passcode.
She
was
led
into
the
internet
hole
of
extensive
and
long-lasting
blockchain
research.
Ooh
haven't
we
all
gotten
sucked
into
things
that
are
shiny
since
then,
she's
been
obsessed
with
the
sub
subject
participated
in
health.
Pekka
Thon's
trained
in
solitude
has
now
deeply
involved
in
the
research
of
blockchain
consensus,
algorithms
and
Europe
Wells
Fargo
Mabel
has
been
an
active
member
and
the
vice
president
of
education
for
stage
coast
Toastmasters
and
founded
the
blockchain
special
interest
group.
A
She
hosts
virtual
education
sessions
nationally
and
in
India
and
a
variety
of
blockchain
concepts
and
is
continually
intrigued
by
the
discovery
of
new
and
different
aspects
of
the
technology.
Our
passion
lies
in
understanding
the
technical
aspects
and
how
the
technology
can
better
connect
the
world
so
and
and
by
the
way
Mabel
came
up
here
from
San
Francisco
just
to
talk
to
us.
So
keep
that
in
mind.
Mabel
so
I'm
gonna
hand
this
over
to
you
we're
gonna.
Do
a
trade
off.
B
B
Alright,
let's
get
started
so
today,
I'll
be
talking
about
hyper,
ledger,
consensus,
algorithms
and
my
agenda
will
include
consensus
fundamentals.
Then
the
hyper
ledger
consensus
algorithms,
the
moment
we're
waiting
for
and
if
we
have
extra
time,
I'll
talk
more
about
getting
involved
with
hyper
ledger
and
what's
involved
in
that,
you
all
took
the
first
step
in
getting
involved
with
hyper
ledger
by
joining
a
hyper
ledger
meetup.
So
congratulations
on
that
all
right,
you're,
probably
wondering
why
am
I
talking
about
consensus
at
a
blockchain
meetup
like
what
is
the
connection
between
blockchain
and
consensus?
B
B
The
consensus
comes
into
play
and
so
you're
probably
wondering
okay,
so
we
need
to
know
that
it's
correct,
but
how
do
we
know
what
if
what's
defined
us
correct,
and
so
that
kind
of
leads
us
to
that
million
dollar
question
of
how
do
we
find
a
grievance
and
you
can
probably
take
a
stab
at
this
question?
It
is
consensus.
B
So
what
is
consensus?
It
is
an
agreement
on
the
order
and
it's
used
to
validate
the
correctness
of
a
transaction.
So,
oh
and
it's
really
what
it's
kind
of
like
the
heart
and
soul
of
a
blockchain
system.
It's
really
what
makes
it
trustless,
and
so
you
probably
heard
of
a
popular
consensus
out
there
and
it's
proof
of
work.
Has
anyone?
Does
anyone
know
what
proof
of
work
is?
A
B
Yeah
that
makes
sense
using
the
word
in
the
definition
any
other
takers.
Okay,
so
sorry,
what's
your
name?
Matt's
Pat's,
Pat's,
sorry,
you're,
making
up
names,
okay,
so
kind
of
like
what
Pat
said
in
proof-of-work,
everyone's
kind
of
like
racing
to
solve
a
cryptographic
puzzle
and
whoever
solves
a
puzzle.
B
The
quickest
gets
in
mind
that
block,
so
it's
very
much
lottery
based
consensus
and
then
that's
kind
of
where
it
makes
it
kind
of
controversial
because
everyone's
trying
to
solve
this
puzzle
the
quickest,
and
that
involves
a
lot
of
lectricity
and
that's
what
makes
it
kind
of
inefficient.
And
so
that's
why
we've
heard
of
like
all
these
eight
million
different
types
of
consensus,
like
proof
of
work,
proof
of
this
proof
of
that.
It's
like
never-ending.
B
B
They
have
to
give
me
order,
and
this
is
a
crucial
because
of
the
double
spend
problem
like
if
I
give
told
Matt
Pat
I'm
going
to
give
you
$10
and
I
told
set
I'm
gonna,
give
him
10
players.
The
order
of
that
promise
means
everything,
because
that
determines
who
gets
my
$10.
So
order
is
everything
and
then
the
second
thing
is
we
need
to
find
agreement
because
we
are
a
consensus
right.
B
So
this
is
a
job
description
and
then,
if
we
were
to
look
for
it,
these
are
the
qualifications
for
that
job
and
the
basic
qualifications.
And
if
you're
gonna
like
dream
about
anything
tonight,
I
hope
you
dream
about,
like
liveness
and
safety
like
just
keep
thinking
about
that.
Just
keep
going
back
and
forth
on
that.
So
liveness
tells
us,
will
it
deliver
and
will
everyone
be
on
the
same
page?
Then
safety
tells
us.
Is
it
consistent?
B
So
these
are
the
basic
qualifications,
but
if
we're
gonna
take
it
a
step
further,
you
did
not
step
backwards,
then
you
would
have
the
nice-to-haves-
and
this
is
kind
of
actually
based
off
of
a
2016
KPMG
study
and
the
study.
The
two
things
that
kind
of
like
stood
out
to
me
from
this
study
was
governance
and
governance
was
interesting
because
it
this
is
going
to
be
completely
engineered
with
block
chain,
because
governance
used
to
be
handled
by
individuals
in
a
company
or
different
business
units,
and
now
much
of
that
is
going
to
be
automated.
B
Another
thing
that
kind
of
stood
out
to
me
was
implementation
approach,
so
this
is
created
in
this
survey
was
taken
in
2016.
It's
like
close
to
the
end
of
2008.
Well,
halfway
there
in
2018
and
I,
haven't
seen
a
solid
blockchain
implementation
yet
and
I
think
it's
not
because
of
the
technology
constraints,
but
it's
very
much
because
of
kind
of
like
a
cultural
shift,
so
we've
gotten
used
to
go
sorry.
B
We've
gone
used
to
kind
of
expecting
to
like
push
in
a
lot
of
data
and
getting
results
quickly,
and
that
is
important,
but
with
blockchain
we're
more
concerned
about
pushing
getting
in
the
right
results.
The
right
answer,
the
first
time
around
and
making
sure
it's
secure.
So
it's
really
about
shifting
priorities.
B
So
we
have
the
qualifications
for
the
right
consensus
so
that
probably
the
million
dollar
question
here
is
what
is
the
best
consensus
out
there?
And
then
you
know
we
can
just
be
done
with
this
presentation,
so
there
is
no
best
consensus
out
there.
Every
problem
has
its
own
personality
and
every
consensus
has
its
own
personality
so
like
if
you're
gonna
solve
for
something
that
you
don't
understand
the
participants
involved,
then
you'd
go
for
more
of
a
Nakamoto
style
of
consensus.
That's
a
little
more
creative,
like
proof
of
work.
B
Proof
of
steak
proof
elapsed
time,
but
if
you
do
understand
the
participants
involved,
which
is
actually
most
cases
most
for
most
businesses
and
you
can
by
process
of
you
should
figure
out
who
is
a
faulty
member,
then
I
would
say:
go
for
something
more
proven
in
the
computer
science
community.
Like
a
Byzantine,
fault-tolerant
algorithm,
so
you're
probably
wondering
what
is
Byzantine
fault,
tolerance
and
it
aims
to
solve
the
Byzantine
generals
problem.
So
these
two
people
shush
tank
and
Lamport.
They
were
like
troubled
by
all
these
problems.
B
They
deal
with
in
distributed
systems,
so
they
wrote
this
paper
to
illustrate
and
they
wrote
it
out.
The
story-
and
the
story
goes
like
this
so
like
there
are
these
Byzantine
generals
and
they're
surrounding
an
enemy
city-
and
there
is
strength,
lies
in
their
unity,
so
they
all
have
to
either
attack
together
or
retreat.
B
Now
you
can
see
in
this
example
they're
all
from
different
movies,
so
there's
no
way
to
communicate
with
each
other
directly,
so
they
need
to
rely
on
a
messenger.
Now,
there's
two
twists
to
this
story.
The
first
twist
is
that
the
messenger
is
a
traitor,
so
T'challa
tells
the
messenger
they're
going
to
attack,
and
then
the
messenger
can
lie
to
you
and
the
matrix
and
say
pachala
is
actually
retreating.
B
A
second
scenario
is
that
one
of
the
generals
can
be
a
traitor,
so
Frodo
wore
the
ring
now
he's
evil
as
part
of
the
city,
and
he
lies
to
everyone
and
says
that
they're
gonna
attack
when
they're,
really
not
so
after
this
paper
came
out.
There
were
like
several
brave
computer
scientists
that
kind
of
worked
to
solve
this
problem,
but
one
solution
that
kind
of
stood
the
test
of
time
and
that
has
been
used
in
several
blockchain
applications
till
this
day,
and
that
is
pbft,
so
Barbara
Liskov
and
miguel
castro.
B
They
came
up
with
this
solution
and
they
were
like
okay,
we
can
guarantee
you
liveness
and
safety
as
long
as
no
more
than
one-third
of
your
participants
are
faulty
and
really
cool.
You
can
deal
with
that.
Also
one
of
your
generals
is
gonna,
be
special
they're
gonna,
be
called
a
primary
and
they're
gonna
be
responsible
for
getting
the
request
from
the
client
and
assigning
order
number.
So
I'm
gonna
get
into
more
of
this
in
a
bit.
So
I
kind
of
really
revealed
this.
B
So
in
this
case,
I
chose
new
to
be
the
primary,
the
special
general,
and
he
has
a
very
important
job
of
assigning
sequence
number,
because
you
remember
order
is
everything,
so
you
find
the
sequence
number.
He
creates
a
little
proposal
and
sends
it
over
to
his
peers.
So
they
get
the
proposal
and
they
move
to
the
repair
phase,
and
now
they
all
discussed
with
each
other
they're
like
okay.
Does
this
make
sense?
Does
it
follow
our
guidelines
and
they're
like
yeah?
It
does
let's
go
ahead
and
move
on
to
the
commit
phase.
B
So
now
they're
in
the
commit
phase,
you
remember
safety
same
input
for
same
output,
so
they
all
individually
execute
the
requests
and
then
they
get
their
answer
and
they're
like
okay.
This
is
my
answer.
What
did
you
get
and
so
they
compare
each
other's
answers
and
they're
like
okay?
We
all
have
like
the
same
answer
or
more
than
one
third
of
us
have
the
same
answer.
B
So
let's
go
ahead
and
commit
it
so
go
ahead
and
commit
it,
and
then
they
tell
the
clients,
hey
your
response,
and
here
is
proof
that
we
came
up
with
the
consensus,
and
so
that
is
how
pbft
works
and
if
you're
gonna,
memorize
and
grill
down
to
one
of
the
consensus,
algorithms
I
would
definitely
recommend
this
one.
Now
before
I
get
into
moment,
we
were
waiting
for,
looks
hyper,
ledger
consensus.
Does
anyone
have
questions
on
what
I
went
through
so
far?
B
B
Yes,
yes,
that's
actually
an
amazing
segue
to
the
next
one.
I'll
go
through,
so
any
other
questions
before
I
move
on
or
okay,
so
hyper
ledger
consensus
today,
I'll
be
going
over
in
D,
so
we
have
our
India
expert
here
and
so
that
inde,
the
indie
project
uses
our
B
of
T
and
plenum.
Then
I'm
going
to
be
going
over
fabric
which
uses
Kafka
right
now,
IRL,
which
uses
a
consensus
called
yet
another
consensus,
confusing
name
and
then
the
next
one
is
socket
Lake,
which
uses
proof
of
elapsed.
B
B
It's
a
project
Indy,
it
is
an
identity,
management
solution
from
sovereign.
Thank
you
and
I.
Think
project
India
is
like
one
of
the
coolest
projects
out
there.
It's
so
there's
three
components
features
to
project.
Indeed,
so
there
is
something
called
a
decentralized
identifier
and
how
it
works.
Is
people
can
issue
different
parts
of
your
identity,
so,
like
your
employer
will
give
you
will
say:
hey
you
are
an
employee
of
a
hyper
ledger.
B
Then
you
would
get
another
D
ID
and
it
would
say,
you're
a
resident
of
Seattle
like
from
the
city,
and
so
these
different
D
IDs
kind
of
make
up
who
you
are
and
then
something
that's
really
cool
and
I
think
this
is
extremely
exciting.
After
the
post,
Facebook
world
breach
post
facebook
hack
world
is
that
you
control
your
identity,
so
you
have
visibility
of
who's
using
your
D
IDs,
you
issue,
you
allow
people
to
see
your
di
your
identity
and
if
there's
something
wrong,
you
there's
a
model.
You
can
follow
to
correct
it.
B
So
you're
not
calling
to
dozens
of
people
for
that
next.
Is
it
supported
zero
knowledge
proof,
so
you
don't
have
to
like
an
employer.
If
they
want
to
know
that
you
came
from
a
certain
University,
the
University,
you
can
say
yes,
this
is
a
student
from
this
university
and
has
this
degree
they
don't
need
to
know
about
all
the
shenanigans
that
went
through
what
happened
in
during
your
university
stay.
They
just
have
to
tell
you
they
have
their.
B
They
have
the
ability
to
tell
you
the
answer,
give
the
answer
that
is
necessary
and
nothing
else.
So.
Project
Indy
is
an
identity
platform,
so
they
need
something
that
is
secure,
so
they
went
for
something
called.
They
looked
at
redundant,
Byzantine,
fault,
tolerance
and
so
resilient
Byzantine
fault.
Tolerance
is
like
PBF,
t's,
overly
cautious
sister.
B
So
if
the
master
copy,
so
the
master
copy
has
like
primary
the
primaries
like
node
0
and
then
the
backup
copy
would
be
like
the
primary
we
know,
and
so
for
some
reason,
like
the
master,
copies
acting
veered
and
we
can
quickly
switch
it
out
with
the
backup
copy
and
just
continue
on
with
our
work
so
project
and
he
was
like
this
is
cool,
but
we're
also
blockchain
solutions.
So
we
need
to
scale
up
right.
B
So
there's
two
major
differences
first
difference
is
that,
because
this
is
a
blockchain
solution,
not
everyone
can
receive
the
request
from
the
client.
So
there's
a
certain
formula
that
determines
that
and
then
another
thing
is
that
you
know
these
woods
can
communicate
with
each
other
directly
like
on
a
point-to-point
fashion.
B
They
need
to
gossip
the
message
through
to
get
through
in
a
decent
amount
of
time,
and
so
they
created
something
called
plenum
which
is
very
much
off
of
our
B
of
T,
and
so
that
is
the
consensus
for
project
indie,
all
right,
moving
on
to
fabric,
so
just
I
think
one
of
the
most
popular
ones
I've
heard
of
so.
This
is
very
much
like
the
Legos
of
permission,
blockchain
solutions,
it's
very
modifiable
and
I
think
that's
what
makes
it
so
popular
is
that
it's
easy
to
kind
of
work
with
pre-existing
systems.
B
B
B
Oh
it's
gone
any
going
back
all
right.
So,
with
Kafka
with
fabric
it
uses
it
uses
Kafka,
which
is
not
Byzantine
fault
tolerance.
So
you
can't
just
you
have
to
know
who
your
who's
in
your
network.
It
is
crash,
fall
torrent
though,
and
Kafka
you
probably
heard
from
it's
like
popular
with
distributed
systems
and
there's
a
lot
of
expertise
around
Kafka.
So
that's
pretty
nice.
So
how
fabrics
consensus
works?
Is
that
there's
an
ordering
service
and
the
name
says
it
all?
It
orders
the
transactions
and
there
are
committers
and
endorsers.
B
All
endorsers
are
committers.
Not
all
committers
are
endorsers,
because
not
everyone
needs
to
do
the
sign-off
they
check
off
on
the
transaction.
So
how
it
works
is
like
the
client
sends
the
request
and
then
the
endorsers
do
an
execution
right
off
the
bat
and
notice
that
the
execution
happens
at
the
very
beginning
versus
and
the
other
ones
execution
happened
at
the
end.
So
this
makes
it
actually
more
scalable,
so
they
do
the
execution.
Then
they
send
a
request
back
to
the
client
right
away.
B
Then
the
clients
like
cool
now
we
need
to
order
these
transactions,
so
the
client
goes
ahead
and
sends
it
to
the
ordering
service
ordering
service
creates
a
block
with
the
order
transactions
and
then
sends
it
over
to
the
committers.
Committers
then
check
it
against
endorsement
policy
and
they're,
like
everything,
seems
a
ok,
let's
go
ahead
and
commit
this,
and
so
that's
how
the
fabric
consensus
works.
Next
up
is
IRA.
B
So
IRA
is
a
mobile,
friendly,
C++
solution,
so
any
mobile
developers
stuff.
We
check
it
out.
They
have
the
libraries
out
there
right
now,
so
how
IRA
works
it
uses
yet
another
consensus,
so
the
client
sends
little
cross
over
oh
by
the
way.
I
didn't
mention
this,
but
IRA
is
also
like
a
project
from
Japan.
So
if
you
look
at
the
documentation
and
the
code
base,
they
use
a
lot
of
like
terminology
from
like
Japanese
terminology,
so
how
it
works
is
like
the
client
sends
over
the
trends.
B
The
transactions
towards
something
called
a
torii
gate,
so
in
a
torii
gate
is
like
in
a
Japanese
temple.
It's
everything
that
goes
through
the
torii
gate
becomes
more
purified,
so
things
go
through
the
torii
gate
and
the
torii
gates
like
okay.
We
need
to
cleanse
this
data
so
we're
not
just
getting
gobbly
grouping,
so
it
finds
one
of
the
members
and
this
in
this
situation
it
picked
11
and
it
says
11,
can
you
do
a
stateless
validation
and
so
11?
Does
that?
B
And
then
it
sends
it
over
to
the
ordering
service
when
the
ordering
service
and
yak
basically
sits
around
it's
like
okay,
let
me
wait
for
so
many
transactions
to
come
in
or
let
me
wait
for
a
certain
amount
of
period
until
I
get
all
these
transactions.
So
the
ordering
service
orders
of
transactions
creates
a
first
version
of
the
block.
Then
it
sends
it
over
to
the
individual
peers.
Then
they
do
a
stateful
validation,
so
they
check
it
against
the
history
and
then
they
make
kind
of
like
a
version.
2
of
the
block.
B
Now
yak
is
a
vote
voting
based
consensus.
So
this
is
when
what
happens
when
it
gets
into
the
consensus
gates
or
consensus
phase.
The
there's
a
leader
and
the
leader
is
in
this
case,
I
just
randomly
chose
neo
again,
and
the
leaders
and
job
is
to
collect
the
boats
and
say
what
order
they
want
these
votes
in.
So
in
this
case,
neo
is
like
okay.
I
want,
obviously
what's
gonna
be.
B
First,
then
second
is
gonna,
be
touch
Allah,
11
and
then
Frodo,
and
so
they
go
ahead
and
they
send
the
votes
in
that
order,
and
now
there's
achieved
a
supermajority.
So
even
though
Frodo
is
number
4,
they're
really
got
to
their
supermajority,
so
they
need
to
continue
on
so
they're
good
to
go
so
they
go
ahead
and
they
commit
in
the
same
order
and
then
so
now
everyone
has
achieved.
B
So
they
have
enough
people
that
have
come
to
an
agreement,
but
remember
liveness:
all
the
participants
have
to
be
on
the
same
page
so
round.
2
Frodo
needs
to
know
what
happened
to
be
to
come
up
with
the
consent
of
the
other
guys.
So
Frodo
was
offline.
This
whole
time,
that's
why
he
was
but
grayed
out,
and
so
he
wakes
up
and
he's
like,
hey
I
was
offline.
B
B
Now,
for
the
last
one
for
the
day,
sawtooth
lake
now
I
have
to
admit
that
I
was
kind
of
judgy
about
sawtooth
late,
because
I
was
like
it's
a
Intel
project
like
mm-hmm.
Is
that
centralized,
but
I
think
you
have
to
look
at
Saatchi
lake
and
there's
actually
a
lot
of
cool
features
and
I
think
it's.
This
was
a
good
point
that
someone
brought
up
in
my
last
presentation
and
they
said
the
fact
that
it's
backed
by
until
it's
makes
it
more.
B
You
know
nothing
is
100%,
centralized
and
I
think
that's
a
hard
thing
to
grasp
in
this
blockchain
space
because
we
are
so
much
for,
like
you
know,
decentralization
being
independent,
but
you
know
the
reality
is
like
we're
not
going
to
be
a
hundred
percent
like
that.
So
just
learning
to
accept
that
so,
but
sorted
lay.
B
Another
thing
that's
pretty
cool
is
that
as
parallel
transaction
execution,
so
it
makes
it
very
scalable,
and
so,
if
there's
a
transaction,
that's
not
related
to
another
one,
it
will
just
fire
through
at
the
same
time.
Another
thing
is
that
it
has
on
chain
governance,
so
you
can
write
a
smart
smart
contract
to
handle
the
configurations,
and
another
thing
is-
and
this
is
related
to
another
hyper
ledger-
project
called
Burroughs,
but
you
can
write
theory,
I'm
smart
contracts
and
run
it
on
sawtooth
link.
So
that's
a
very
neat
marriage
there.
B
B
So
they
all
like
kind
of
like
in
proof
of
work.
Everyone
has
a
specialized
hardware
to
solve
these
puzzles
in
proof
of
elapsed
time.
Everyone
owns
this
like
specialized
hardware
provided
by
Intel
right
now,
and
it's
called
an
SG
x
and
this
chip
has
it's
almost
impossible
to
hack
into
and
manipulate
the
code.
B
B
Now
everyone
wants
to
mind
this
block
this
transaction,
so
what
they
do
is
they
go
to
their
SJS
and
they're
like
hey,
give
me
that
wait
time,
and
so
the
sjx
is
like.
Okay,
here's
your
wait.
Time
go
to
sleep
for
this
amount
of
time,
they're
like
okay,
so
they
go
to
sleep
for
that
certain
amount
of
time,
then
they
wake
up.
They're
real
time
has
expired
and
everyone
gets
a
different
wait
time
and
it's
all
random
and
so
their
rate
time
expires
and
then
they
wake
up
and
they're
like
hey.
B
Can
you
verify
to
everyone
that
I
raided
the
time
you
told
me
to
me
they're
like
okay,
you
did
wait.
The
time
I
told
you
to
wait,
and
so
in
this
case,
11
had
the
shortest
wait
time.
So
11
gets
in
mind
that
block,
so
she
executes
sin
and
then
sends
it
over
to
the
peers
and
they
all
committed,
and
so
this
is
actually
a
lottery
based
system.
Someone
at
random
can
mine
the
block,
and
that
is
how
proof
of
elapsed.
Time
works
all
right.
Takeaways
consensus
is
the
heart
and
soul
of
a
block.
B
B
Personally,
I
was
working
on
the
IRS
light
and
I
didn't
realize
that
they
actually
changed
the
consensus
to
sumeragi
I
mean
they
change
it
from
sumeragi
to
yeah,
and
so
you
definitely
don't
memorize
and
don't
fall
in
love
with
the
details,
but
understand
the
concepts
and
think
of
learn
how
to
think
about
this
all
in
a
critical
manner,
and
another
thing
is
no
solution
is
perfect
and
I.
Think
that's
the
problem.
A
lot
of
people
believe
that
blockchain
is
secure
and
then
they're
like
forget
all
the
security
measures.