1. Bitcoin
Viet-­‐Trung
Tran
Vn-­‐S3c
2/07/11
1

2. Bitcoin
• Developed
by
Satoshi
Nakamoto
• First
“currency”
without
a
central
issuer
• Distributed
Database
to
journal
transacHons
• Peer-­‐to-­‐peer
based
Crypto-­‐Currency
• Relies
on
Public/Private
Key
Cryptography
• Open
Source,
C++
Code
available
on
Github
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3. Bitcoin
2
• Allows
for
fast
transfer
of
value
through
Internet
without
middlemen
• 3rd
parHes
can't
prevent
or
control
transacHons
• Safe
from
instability
of
fracHonal
reserve
system
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4. Bitcoin
coins
• Saved
on
PC
in
the
form
of
a
wallet
file
or
3rd
party
exchange
websites
• Divisible
up
to
0.00000001
or
10-­‐8
of
a
BTC
allowing
for
micro-­‐payments
• Value
is
inherent,
not
backed
by
anything,
as
is
standard
for
fiat
currencies
presently.
• Predictable
inflaHon
built
into
system
• 21
million
coins
will
ever
exist
• ~5
million
coins
at
present
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5. Bitcoin
transacHons
• Sender
relinquishes
ownership
by
signing
hem
them
with
her
own
private
key
r
• TransacHon
is
broadcast
to
the
peer-­‐to-­‐peer
network
ks
• Fast:
1
to
30
minutes
to
complete
• Free:
PC
&
Internet
is
all
you
need
• Permanent:
no
chargebacks/bounced
checks
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6. Now
1BTC
=
16,80
USD
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7. 2/07/11
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8. TransacHons
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9. Double
spending
• No
central
authority
• Using
distributed
Hmestamp
servers
• Each
peer
can
work
as
a
Hmestamp
server
if
wished
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10. Block
chain
• Blocks
in
the
main
chain
(black)
are
the
longest
series
of
blocks
that
go
from
the
genesis
block
(green)
to
the
current
block.
Orphan
blocks
longest
s
block
(purple)
are
blocks
that
are
not
in
ocks
ngest
the
longest
chain.
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11. Role
of
Hmestamp
server
• Collect
recent
transacHons
• Mining
new
block
based
on
– Previous
block
of
the
longest
chain
– Recent
transacHons
– Nonce
(random
number)
• If
found
a
block,
broadcast
it
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12. Network
rules
• For
the
whole
network
– 1
BLOCK
created,
50
BTC
reward
– 1
Block
created
for
around
every
10
minutes
• Controlled
by
the
difficulty
of
block
generaHon
– Block
value
<
an
agreement
target
value
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13. IncenHve
of
working
as
a
Hmestamp
server
• Get
reward
for
each
created
block
– 50
BTC
for
the
moment
– Reduce
every
4
years
(every
210,000
blocks)
• TransacHon
fee
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14. How
the
system
works
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15. Disk
Space
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16. TransacHon
verificaHon
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17. Conclusion
• Well
design
• But
not
green
– Non-­‐stop
consummaHon
of
CPU,
Storage,
Network
and
it’s
ALL
about
power
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18. transacHon
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