<s>
The	O
Lightning	B-Protocol
Network	I-Protocol
(	O
LN	O
)	O
is	O
a	O
"	O
layer	O
2	O
"	O
payment	O
protocol	O
layered	O
on	O
top	O
of	O
Bitcoin	B-Protocol
(	O
and	O
other	O
blockchains	B-Application
and	O
cryptocurrencies	O
)	O
.	O
</s>
<s>
It	O
is	O
intended	O
to	O
enable	O
fast	O
transactions	O
among	O
participating	O
nodes	O
and	O
has	O
been	O
proposed	O
as	O
a	O
solution	O
to	O
the	O
bitcoin	B-Protocol
scalability	I-Protocol
problem	I-Protocol
.	O
</s>
<s>
Normal	O
use	O
of	O
the	O
Lightning	B-Protocol
Network	I-Protocol
consists	O
of	O
opening	O
a	O
payment	O
channel	O
by	O
committing	O
a	O
funding	O
transaction	O
to	O
the	O
relevant	O
base	O
blockchain	B-Application
(	O
layer	O
1	O
)	O
,	O
followed	O
by	O
making	O
any	O
number	O
of	O
Lightning	B-Protocol
Network	I-Protocol
transactions	O
that	O
update	O
the	O
tentative	O
distribution	O
of	O
the	O
channel	O
's	O
funds	O
without	O
broadcasting	O
those	O
to	O
the	O
blockchain	B-Application
,	O
optionally	O
followed	O
by	O
closing	O
the	O
payment	O
channel	O
by	O
broadcasting	O
the	O
final	O
version	O
of	O
the	O
settlement	O
transaction	O
to	O
distribute	O
the	O
channel	O
's	O
funds	O
.	O
</s>
<s>
Joseph	O
Poon	O
and	O
Thaddeus	O
Dryja	O
published	O
a	O
draft	O
of	O
the	O
Lightning	B-Protocol
Network	I-Protocol
white	O
paper	O
in	O
February	O
2015	O
.	O
</s>
<s>
On	O
January	O
19	O
,	O
2019	O
,	O
pseudonymous	O
Twitter	B-Application
user	O
hodlonaut	O
began	O
a	O
game-like	O
promotional	O
test	O
of	O
the	O
Lightning	B-Protocol
Network	I-Protocol
by	O
sending	O
100,000	O
satoshis	B-Protocol
(	O
0.001	O
bitcoin	B-Protocol
)	O
to	O
a	O
trusted	O
recipient	O
where	O
each	O
recipient	O
added	O
10,000	O
satoshis	B-Protocol
(	O
$0.34	O
at	O
the	O
time	O
)	O
to	O
send	O
to	O
the	O
next	O
trusted	O
recipient	O
.	O
</s>
<s>
The	O
"	O
lightning	O
torch	O
"	O
payment	O
reached	O
notable	O
personalities	O
including	O
Twitter	B-Application
CEO	O
Jack	O
Dorsey	O
,	O
Litecoin	B-Protocol
Creator	O
Charlie	O
Lee	O
,	O
Lightning	O
Labs	O
CEO	O
Elizabeth	O
Stark	O
,	O
and	O
Binance	O
CEO	O
"	O
CZ	O
"	O
Changpeng	O
Zhao	O
,	O
among	O
others	O
.	O
</s>
<s>
Andreas	O
Antonopoulos	O
has	O
referred	O
to	O
the	O
Lightning	B-Protocol
Network	I-Protocol
as	O
a	O
second	O
layer	O
routing	O
network	O
.	O
</s>
<s>
The	O
payment	O
channels	O
allow	O
participants	O
to	O
transfer	O
money	O
to	O
each	O
other	O
without	O
having	O
to	O
make	O
all	O
their	O
transactions	O
public	O
on	O
the	O
blockchain	B-Application
.	O
</s>
<s>
When	O
opening	O
a	O
channel	O
,	O
participants	O
must	O
commit	O
an	O
amount	O
(	O
in	O
a	O
funding	O
transaction	O
,	O
which	O
is	O
on	O
the	O
blockchain	B-Application
)	O
.	O
</s>
<s>
There	O
are	O
four	O
major	O
implementations	O
of	O
Lightning	O
that	O
implement	O
the	O
specification	O
:	O
Lightning	B-Protocol
Network	I-Protocol
Daemon	O
,	O
CoreLightning	O
,	O
Eclair	O
,	O
and	O
Lightning	O
Dev	O
Kit	O
.	O
</s>
<s>
There	O
are	O
several	O
claimed	O
future	O
benefits	O
to	O
using	O
the	O
Lightning	B-Protocol
Network	I-Protocol
compared	O
to	O
on-chain	O
transactions	O
:	O
</s>
<s>
Granularity	B-Operating_System
:	O
According	O
to	O
Andreas	O
Antonopoulos	O
,	O
some	O
implementations	O
of	O
the	O
Lightning	B-Protocol
Network	I-Protocol
allow	O
for	O
payments	O
that	O
are	O
smaller	O
than	O
a	O
satoshi	O
,	O
the	O
smallest	O
unit	O
on	O
the	O
base	O
layer	O
of	O
bitcoin	B-Protocol
.	O
</s>
<s>
Privacy	O
:	O
The	O
details	O
of	O
individual	O
lightning	B-Protocol
network	I-Protocol
payments	O
are	O
not	O
publicly	O
recorded	O
on	O
the	O
blockchain	B-Application
.	O
</s>
<s>
Lightning	B-Protocol
network	I-Protocol
payments	O
may	O
be	O
routed	O
through	O
many	O
sequential	O
channels	O
where	O
each	O
node	O
operator	O
will	O
be	O
able	O
to	O
see	O
payments	O
across	O
their	O
channels	O
,	O
but	O
they	O
will	O
not	O
be	O
able	O
to	O
see	O
the	O
source	O
nor	O
destination	O
of	O
those	O
funds	O
if	O
they	O
are	O
non-adjacent	O
.	O
</s>
<s>
Speed	O
:	O
Settlement	O
time	O
for	O
lightning	B-Protocol
network	I-Protocol
transactions	O
is	O
under	O
a	O
minute	O
and	O
can	O
occur	O
in	O
milliseconds	O
.	O
</s>
<s>
Confirmation	O
time	O
on	O
the	O
bitcoin	B-Protocol
blockchain	B-Application
,	O
for	O
comparison	O
,	O
occurs	O
every	O
ten	O
minutes	O
,	O
on	O
average	O
.	O
</s>
<s>
The	O
Lightning	B-Protocol
Network	I-Protocol
is	O
made	O
up	O
of	O
bidirectional	O
payment	O
channels	O
between	O
two	O
nodes	O
which	O
combined	O
create	O
smart	B-Application
contracts	I-Application
.	O
</s>
<s>
If	O
at	O
any	O
time	O
either	O
party	O
drops	O
the	O
channel	O
,	O
the	O
channel	O
will	O
close	O
and	O
be	O
settled	O
on	O
the	O
blockchain	B-Application
.	O
</s>
<s>
Due	O
to	O
the	O
nature	O
of	O
the	O
Lightning	B-Protocol
Network	I-Protocol
's	O
dispute	O
mechanism	O
,	O
which	O
requires	O
all	O
users	O
to	O
watch	O
the	O
blockchain	B-Application
constantly	O
for	O
fraud	O
,	O
the	O
concept	O
of	O
a	O
"	O
watchtower	O
"	O
has	O
been	O
developed	O
,	O
where	O
trust	O
can	O
be	O
outsourced	O
to	O
watchtower	O
nodes	O
to	O
monitor	O
for	O
fraud	O
.	O
</s>
<s>
This	O
is	O
done	O
using	O
an	O
onion	B-Protocol
routing	I-Protocol
technique	O
similar	O
to	O
Tor	O
,	O
and	O
it	O
requires	O
that	O
the	O
sender	O
and	O
receiver	O
of	O
the	O
payment	O
have	O
enough	O
established	O
peers	O
in	O
common	O
to	O
find	O
a	O
path	O
for	O
the	O
payment	O
.	O
</s>
<s>
Bob	O
wants	O
to	O
pay	O
Alice	O
1	B-Protocol
BTC	I-Protocol
but	O
Bob	O
and	O
Alice	O
do	O
n't	O
have	O
a	O
channel	O
open	O
with	O
each	O
other	O
.	O
</s>
<s>
Laszlo	O
Hanyecz	O
,	O
who	O
gained	O
fame	O
in	O
the	O
cryptocurrency	O
community	O
for	O
paying	O
10,000	O
BTC	O
for	O
two	O
pizzas	O
in	O
2010	O
,	O
bought	O
two	O
more	O
pizzas	O
in	O
2018	O
using	O
Lightning	B-Protocol
Network	I-Protocol
and	O
paid	O
0.00649	O
BTC	O
.	O
</s>
