7/21/2019 24-bitcoin

1/36

EE324 DISTRIBUTED SYST

L24-BitCoin and Security

7/21/2019 24-bitcoin

2/36

Reading

Chicago Fed Letter Bitcoin: A prier !" Fran#oi$ R% &e'de( $enior econ http:))***%chicago+ed%org)digita',a$$et$)p-!'ica

hicago,+ed,'etter)2./3)c+'dece!er2./3,3/0%pd

A ca$-a' reading 1-ch 'e$$ technica'

The origina' BitCoin paper http:))!itcoin%org)!itcoin%pd+

-!'i$hed on'ine *ith $o-rce code

http://www.chicagofed.org/digital_assets/publications/chicago_fed_letter/2013/cfldecember2013_317.pdfhttp://www.chicagofed.org/digital_assets/publications/chicago_fed_letter/2013/cfldecember2013_317.pdfhttp://www.chicagofed.org/digital_assets/publications/chicago_fed_letter/2013/cfldecember2013_317.pdfhttp://bitcoin.org/bitcoin.pdfhttp://bitcoin.org/bitcoin.pdfhttp://www.chicagofed.org/digital_assets/publications/chicago_fed_letter/2013/cfldecember2013_317.pdfhttp://www.chicagofed.org/digital_assets/publications/chicago_fed_letter/2013/cfldecember2013_317.pdfhttp://www.chicagofed.org/digital_assets/publications/chicago_fed_letter/2013/cfldecember2013_317.pdfhttp://www.chicagofed.org/digital_assets/publications/chicago_fed_letter/2013/cfldecember2013_317.pdfhttp://www.chicagofed.org/digital_assets/publications/chicago_fed_letter/2013/cfldecember2013_317.pdfhttp://www.chicagofed.org/digital_assets/publications/chicago_fed_letter/2013/cfldecember2013_317.pdf

7/21/2019 24-bitcoin

3/36

BitCoin

La-nched in 2..

A eer5to5peer E'ectronic Ca$h S"$te

6h" $t-d" BitCoin7 &irt-a' c-rrenc" capt-re$ an" a$pect$ o+ $ec-rit" in it$

nt%

9e* +or o+ c-rrenc" that a" tae o++ or e;en rep'ace-rrencie$% 9-ero-$ paper$ in Econoic$ and Cop-ter Science%

Baid- accept$ it a$ a +or o+ pa"ent%

Artic'e$ +ro FED( ne*$ paper$( etc%

7/21/2019 24-bitcoin

4/36

=;er;ie* o+ Toda">$ Lect-re

Intro to BitCoin$ 1non5technica'

Cr"ptographic ?a$he$ -!'ic e" cr"pto and digita' $ignat-re Technica' o;er;ie* o+ BitCoin$ The practice o+ ining BitCoin$ 1$"$te>$ per$pect

7/21/2019 24-bitcoin

5/36

Si@e o+ the BitCoin Econo"

9-!er o+ BitCoin$ in circ-'ation //% i''ion 1Dec/3

Tota' n-!er o+ BitCoin$ generated cannot e

7/21/2019 24-bitcoin

6/36

BitCoin: Cha''enge$

A'' ;irt-a' c-rrenc" -$t addre$$ the +o''o*ing cha''eng Creation o+ a ;irt-a' coin)note

?o* i$ it created in the +ir$t p'ace7

?o* do "o- pre;ent in+'ation7 16hat pre;ent$ an"one +ro creati$7

&a'idation

I$ the coin 'egit7 1proo+5o+5*or ?o* do "o- pre;ent a coin +ro do-!'e5$pending7

BitCoin tae$ a in+ra$tr-ct-re5'e$$ approach Re'" on proo+ in$tead o+ tr-$t

9o centra' !an or c'earing ho-$e

7/21/2019 24-bitcoin

7/36

7/21/2019 24-bitcoin

8/36

=;er;ie* o+ Toda">$ Lect-re

Intro to BitCoin$ 1non5technica'

Sec-rit" =;er;ie* Digita' $ignat-re Cr"ptographic ?a$he$

Technica' o;er;ie* o+ BitCoin$

The practice o+ ining BitCoin$ 1$"$te>$ per$pect

7/21/2019 24-bitcoin

9/36

Fo-r coponent$ in $ec-re co-on A-thentication

Con+identia'it" Integrit" A;ai'a!i'it"

7/21/2019 24-bitcoin

10/36

6hat do *e *ant to $ec-re7

A-thentication 16ho a I ta'ing to7 Identi+ication and a$$-rance o+ the origin o+ in+oratio

Con+identia'it" 1I$ " data hidden7 Concea'ent o+ in+oration

Integrit" 1?a$ " data !een odi+ied7

re;ent iproper and -na-thori@ed change$ A;ai'a!i'it" 1Can I -$e the re$o-rce$7

The a!i'it" to -$e the in+oration or re$o-rce de$ired

7/21/2019 24-bitcoin

11/36

Fro the per$pecti;e o+ BitCoin

A-thentication A I pa"ing the right per$on7 9ot $oe other iper$o

Integrit" I$ the coin do-!'e5$pent7

Can an attacer re;er$e or change tran$ation$7

A;ai'a!i'it" Can I ae a tran$action an"tie I *ant7

Con+identia'it" 9ot ;er" re'e;ant% B-t pri;ac" i$ iportant%

7/21/2019 24-bitcoin

12/36

Fro the per$pecti;e o+ BitCoin

A-thentication-!'ic e" Cr"pto: Digita' Signat A I pa"ing the right per$on7 9ot $oe other iper$o

Integrit" Digita' Signat-re$ and Cr"ptographic ? I$ the coin do-!'e5$pent7

Can an attacer re;er$e or change tran$ation$7

A;ai'a!i'it" Can I ae a tran$action an"tie I *ant7

Con+identia'it" 9ot ;er" re'e;ant% B-t pri;ac" i$ iportant%

7/21/2019 24-bitcoin

13/36

-!'ic e" Cr"pto: Encr"ption

e" pair: p-!'ic e" and pri;ate e"

7/21/2019 24-bitcoin

14/36

-!'ic e" Cr"pto E

7/21/2019 24-bitcoin

15/36

-!'ic e" Cr"pto E

7/21/2019 24-bitcoin

16/36

-!'ic e" Cr"pto: Digita' Signat-re

Fir$t( create a e$$age dige$t -$ing a cr"ptograph

Then( encr"pt the e$$age dige$t *ith "o-r pri;at

Authentic

Integrity

Non-repu

7/21/2019 24-bitcoin

17/36

17

Cr"ptographic ?a$h F-nction$

Con$i$tent: ha$h1 a'*a"$ "ie'd$ $ae re$-'t =ne5*a": gi;en Y( hard to +ind $%t% ha$h1 Y Co''i$ion re$i$tant: gi;en ha$h16 N( hard to +

$-ch that ha$h1 N

Hash

Fn

Message of arbitrary lengthFixed Size

Hash

7/21/2019 24-bitcoin

18/36

=;er;ie* o+ Toda">$ Lect-re

Intro to BitCoin 1non5technica'

Sec-rit" =;er;ie* BitCoin: Technica' Detai'$ The practice o+ ining BitCoin$ 1$"$te>$ per$pect

7/21/2019 24-bitcoin

19/36

Bac to BitCoin$

&a'idation I$ the coin 'egit7 1proo+5o+5*or U$e o+ Cr"ptograp ?o* do "o- pre;ent a coin +ro do-!'e5$pending7

to a'' node$

Creation o+ a ;irt-a' coin)note

?o* i$ it created in the +ir$t p'ace7

ro;ide incenti;$ ?o* do "o- pre;ent in+'ation7 16hat pre;ent$ an"one

ing 'ot$ o+ coin$7 Liit the creation rate o+ the BitC

7/21/2019 24-bitcoin

20/36

BitCoin

E'ectronic coin chain o+ digita' $ignat-re$

BitCoin tran$+er: Sign1re;io-$ tran$action O 9e* -!'ic e"

An"one can ;eri+" 1n5/th o*ner tran$+erred thi$ too*ner%

An"one can +o''o* the hi$tor"Pi;en a BitCoin

7/21/2019 24-bitcoin

21/36

U$e o+ Cr"ptographic ?a$he$

roo+5o+5*or B'oc contain$ tran$action$ to !e ;a'idated and pre;io-$ ha$h ic a no-ce $-ch that ?1pre; ha$h( no-nce( T

7/21/2019 24-bitcoin

22/36

re;enting Do-!'e5$pending

The on'" *a" i$ to !e a*are o+ a'' tran$action$%

Each node 1iner ;eri+ie$ that thi$ i$ the +ir$t $pene BitCoin !" the pa"er%

=n'" *hen it i$ ;eri+ied it generate$ the proo+5o+5*tatch it to the c-rrent chain%

7/21/2019 24-bitcoin

23/36

BitCoin 9et*or

Each 2 node r-n$ the +o''o*ing a'gorith Q!itcoin:

9e* tran$action$ are !roadca$t to a'' node$% Each node co''ect$ ne* tran$action$ into a !'oc% Each node *or$ on +inding a proo+5o+5*or +or it$ !'oc% 1?a

!a!i'i$tic% The one to +ini$h ear'" *i'' pro!a!'" *in% 6hen a node +ind$ a proo+5o+5*or( it !roadca$t$ the !'oc to

9ode$ accept the !'oc on'" i+ a'' tran$action$ in it are ;a'id 1dre checing and not a'read" $pent 1chec a'' the tran$action$ 9ode$ e

7/21/2019 24-bitcoin

24/36

Tie !reaing

T*o node$ a" +ind a correct !'oc $i-'taneo-$'" eep !oth and *or on the +ir$t one I+ one gro*$ 'onger than the other( tae the 'onger on

To di!erent

"loc# chains $or"loc#s% maysatis&y there'uired proo&-o&-or#(

7/21/2019 24-bitcoin

25/36

Re;erting i$ hard

Re;erting get$ e

7/21/2019 24-bitcoin

26/36

ractica' Liitation

At 'ea$t /. in$ to ;eri+" a tran$action% Agree to pa" 6ait +or one !'oc 1/. in$ +or the tran$action to go B-t( +or a 'arge tran$action 1 *ait 'onger% Beca-$e

'onger it !ecoe$ ore $ec-re% For 'arge ( "o- *ac$ 1/ ho-r%

Fid-ciar" c-rrenc" 9o intrin$ic ;a'-e%

7/21/2019 24-bitcoin

27/36

Ip'eentation i$$-e$

Broadca$t

eeping trac o+ node e!er$hip Creating a !'oc

?o* do "o- agree on *hich tran$action$ go into a !'o

6hat i+ the" are di++erent7

6hat i+ "o- cheat !" inc'-ding a $a'' n-!er o+ trand $tart ining ear'"7

9ot an$*ered in the paper% B-t( perhap$ the ip'en addre$$e$ thi$ in partTopic +or ore re$earch

7/21/2019 24-bitcoin

28/36

=ptii@ation$

Mer'e Tree =n'" eep the root ha$h

De'ete the interior ha$h ;a'-e$ to $a;e di$

B'oc header on'" contain$ the root ha$h

B'oc header i$ a!o-t . !"te$

. !"te$ per)hr 24 hr$ 3 4%2 MB)"ear

6h" eep -$e a Mer'e tree7

7/21/2019 24-bitcoin

29/36

Sip'i+ied pa"ent ;eri+ication

An" -$er can ;eri+" a tran$action ea$i'" !" a$ing a

Fir$t( get the 'onge$t proo+5o+5*or chain V-er" the !'oc that the tran$action to !e ;eri+ied =n'" need ?a$h./ and ?a$h2 to ;eri+" not the en

7/21/2019 24-bitcoin

30/36

BitCoin Econoic$

Rate 'iiting on the creation o+ a ne* !'oc

Adapt to the Wnet*or>$ capacit"X A !'oc created e;er" /. in$ 1$i< !'oc$ e;er" ho-r

?o*7 Di++ic-'t" i$ ad-$ted e;er" t*o *ee$ to eep the rate +i

7/21/2019 24-bitcoin

31/36

=;er;ie* o+ Toda">$ Lect-re

Intro to BitCoin 1non5technica'

Sec-rit" =;er;ie* BitCoin: Technica' Detai'$ The practice o+ ining BitCoin$ 1$"$te>$ per$pect

Iage)data +ro

7/21/2019 24-bitcoin

32/36

Iage)data +rohttp:))***%to$hard*are%co)re;ie*$)!itcoin5ining5ae5one"(

PU: Radeon ?D . a!o-t 0.. M?)$

B-tter+'" La!$: FPA( ASIC

http://www.tomshardware.com/reviews/bitcoin-mining-make-money,3514-4.htmlhttp://www.tomshardware.com/reviews/bitcoin-mining-make-money,3514-4.html

7/21/2019 24-bitcoin

33/36

Spartan/-)01

BFL SingleBFLmini,ig

A+alon BFL ASICminer

Typeilin.F3A

AlteraF3A F3A ASIC ASIC ASIC

3rocess 40 nm 40 nm $5% 40 nm $5% ))1 nm /0 nm )1 nm

6ash ,ate3er Chip

2)1 *67s 4)0 *67s/01-801*67s

291 *67s 4 67s 11 *67s

3oer:ra

)0 ; 41 ; 0 ; 2(9 ; 1 ; 2(0 ;

S? 7 *67s ) to 2(0 1(80 1(/ @aries @aries @aries

NotesTypically )to 4 F3As 2 F3As

3er Board

2 F3As

3er Board)8 to )9

3riced In

BTC$ rices

BFLAnticipate

s A Slight,eduction

3riced In

BTC$ rices

d 1h d ! +' ' !

http://rover.ebay.com/rover/1/711-53200-19255-0/1?toolid=10029&campid=CAMPAIGNID&customid=CUSTOMID&catId=293&type=2&ext=301007803732&item=301007803732http://rover.ebay.com/rover/1/711-53200-19255-0/1?toolid=10029&campid=CAMPAIGNID&customid=CUSTOMID&catId=293&type=2&ext=301007803732&item=301007803732http://rover.ebay.com/rover/1/711-53200-19255-0/1?toolid=10029&campid=CAMPAIGNID&customid=CUSTOMID&catId=293&type=2&ext=301007803732&item=301007803732http://rover.ebay.com/rover/1/711-53200-19255-0/1?toolid=10029&campid=CAMPAIGNID&customid=CUSTOMID&catId=293&type=2&ext=301007803732&item=301007803732https://products.butterflylabs.com/https://products.butterflylabs.com/

7/21/2019 24-bitcoin

34/36

?ard*are 6ar 1http$:))prod-ct$%!-tter+'"'a!$

http77("utteryla"s(com7

http$:))prod-ct$%!-tter+'"'a!$%co)

S

https://products.butterflylabs.com/http://www.butterflylabs.com/https://products.butterflylabs.com/https://products.butterflylabs.com/http://www.butterflylabs.com/https://products.butterflylabs.com/

7/21/2019 24-bitcoin

35/36

S-ar"

BitCoin co!ined techni8-e$ +ro cr"pto and the right

9ice de$ign A trait +or pop-'ar $"$te$

BitCoin i$ !ecoing ind-$tria'i@ed% Miner$ +or a poo'% Mining hard*are !ecoe$ $ophi$ticated%

BitCoin e

7/21/2019 24-bitcoin

36/36

Re+erence$

http:))

***%to$hard*are%co)re;ie*$)!itcoin5ining5e"(3/4%ht'

Bitcoin: A prier !" Fran#oi$ R% &e'de( $enior econ Bitcoin: A eer5to5eer E'ectronic Ca$h S"$te( Sat

oto

http://www.tomshardware.com/reviews/bitcoin-mining-make-money,3514.htmlhttp://www.tomshardware.com/reviews/bitcoin-mining-make-money,3514.htmlhttp://www.tomshardware.com/reviews/bitcoin-mining-make-money,3514.htmlhttp://www.tomshardware.com/reviews/bitcoin-mining-make-money,3514.htmlhttp://www.tomshardware.com/reviews/bitcoin-mining-make-money,3514.htmlhttp://www.tomshardware.com/reviews/bitcoin-mining-make-money,3514.html