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D O C U M E N T C O I N Chris Anderson @jchris jchris@gmail.com - - PowerPoint PPT Presentation

Aug 03, 2023 219 likes •637 views

C RY P T O C U R R E N C Y F O R T H E G I F T E C O N O M Y D O C U M E N T C O I N Chris Anderson @jchris jchris@gmail.com QCon London 2016 TA K E H O M E L E S S O N S Blockchain without global consensus is interesting

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SLIDE 1

D O C U M E N T C O I N

C RY P T O C U R R E N C Y F O R T H E G I F T E C O N O M Y

Chris Anderson @jchris jchris@gmail.com QCon London 2016

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SLIDE 2

TA K E H O M E L E S S O N S

  • Blockchain without global consensus is interesting
  • WebCrypto APIs will bring innovation to blockchain

applications

  • Application developers not cryptographers?!?
  • IETF JOSE means standardized implementations
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SLIDE 3

T H E D O Y L E O W L

https://www.flickr.com/photos/ultimatekiwi/5154416336/

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SLIDE 4

I D E O L O G Y

B A C K G R O U N D A S S U M P T I O N S

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SLIDE 5

L E G I B I L I T Y

W H E R E W O U L D Y O U R A T H E R L I V E ?

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SLIDE 6

VA L U E

H O W W E K N O W S O M E T H I N G I S I M P O R TA N T

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SLIDE 7

I N E Q U A L I T Y

9 9 % O F P E O P L E H A V E 6 0 % O F T H E W E A LT H

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SLIDE 8

P R O G R E S S I V I S M

A D J U S T I N G T H E C U R V E

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SLIDE 9

G L O B A L PA R T I A L O R D E R I N G

D O W E N E E D I T ?

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SLIDE 10

P I R A H Ã

W E C A N L I V E W I T H O U T N U M B E R S

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SLIDE 11

G I F T E C O N O M Y

C A N W E S C A L E I T ?

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SLIDE 12

S U B J E C T I V E VA L U E

E V E RY O N E S E E S A D I F F E R E N T PA R T I A L O R D E R I N G

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SLIDE 13

W E B O F T R U S T

P R I O R A R T

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SLIDE 14

C E R T I F I C AT E A U T H O R I T Y

W H O WA T C H E S T H E WA T C H E R S ?

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SLIDE 15

N O W W E H AV E N P R O B L E M S

K E Y S I G N I N G PA R T Y

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SLIDE 16

O B J E C T B L O C K C H A I N

  • Blockchain allows us to create digital objects
  • Heirlooms
  • Gamify the web of trust
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SLIDE 17

I N T E R N E T T H I N G S

F R O M C L A S S E S T O I N S TA N C E S

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SLIDE 18

G I V E T R E E

  • Per document blockchain
  • Don’t wait for global consensus
  • Data provenance structures allows the tracking of how
  • wnership of a piece of data got to you
  • TODO: Encrypt the content of the coins.
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SLIDE 19

G I V E T R E E

s(A1)

mint B1

s(mint)

A1 Child nodes are signed by the keys encoded as

  • wner of parent blocks.

A2

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SLIDE 20

VA L I D AT E T H E G I V E T R E E

  • Verify the root content hash and mint signature match

the unique coin id.

  • For each child in the tree, verify that the signature is

correct and comes from the public key listed in the parent block.

  • Application level policy can flag branches of the tree

that exceed a give limit. Physical objects are simulated with a give limit of one.

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SLIDE 21

G I V E T R E E

to (Maude keys)

  • n (content hash)

signed (Maude)

mint mint

Maude

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SLIDE 22

G I V E T R E E

to (The Dude)

  • n (parent hash)

signed (Maude)

mint

s(mint)

A1 A1

Maude The Dude

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SLIDE 23

G I V E T R E E

to (Donny keys)

  • n (parent hash)

signed (The Dude)

s(A1)

mint

s(mint)

B1 A1 B1

Maude The Dude Donny

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SLIDE 24

G I V E T R E E

to (Walter keys)

  • n (parent hash)

signed (The Dude)

s(A1)

mint

s(mint)

B2 A1 B1 B2 "It went OK, the old man told me to take any rug in the house."

Maude The Dude Donny Walter

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SLIDE 25

G I V E T R E E

to (Walter keys)

  • n (parent hash)

signed (The Dude)

s(A1)

mint

s(mint)

B1 A1 A2 B1 B2

Maude The Dude Donny Walter Bunny

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SLIDE 26

G I V E T R E E

to (Larry keys)

  • n (parent hash)

signed (Bunny)

s(A1)

mint

s(A2) s(mint)

C1 A1 A2 B1 B2 C1

Maude The Dude Donny Walter Bunny Larry

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SLIDE 27

L I M I TAT I O N S

  • The model, even if perfectly implemented, isn’t

designed to prevent double spending, just to detect it.

  • Research project, currently only dealing with public

content and signatures.

  • Haven’t implemented the Bill Murray rule yet.
  • Want multi-sig mint blocks
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SLIDE 28

I M P L E M E N TAT I O N

  • Cisco’s JOSE https://github.com/cisco/node-jose
  • Prova test runner http://github.com/azer/prova
  • Recursion!
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SLIDE 29

P R O VA

T E S T I N T H E B R O W S E R W I T H O U T A N Y B U I L D S C R I P T S

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SLIDE 30

P R O VA

A U T O M A G I C A L R E L O A D A N D R U N

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SLIDE 31

C I S C O N O D E - J O S E

E A S Y A N D C O N S I S T E N T W R A P P E R A R O U N D W E B C RY P T O

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SLIDE 32

VA L I D AT E A C O I N

  • Validate the root of the Give Tree
  • Coin ID is correct
  • Content signature matches
  • Recursively validate all child nodes
  • Give limit policy violations are business errors, not

validation errors

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SLIDE 33

VA L I D AT E T H E R O O T

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SLIDE 34

VA L I D AT E T H E R O O T

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SLIDE 35

VA L I D AT E C H I L D R E N

Empty Callback!

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SLIDE 36

VA L I D AT E C H I L D R E N

Recursion!

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SLIDE 37

N E X T S T E P S

  • Encrypted content
  • PouchDB storage & sync
  • Photo sharing application
  • Public key graph browser
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SLIDE 38

… P R O F I T

  • Distributed PKI
  • Illustrate to users the value
  • f partial disclosure
  • Ecosystem interop
  • Native HTML5 blockchain
  • Platform for p2p social apps
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SLIDE 39

C O N C L U S I O N

  • We are the world

computer, build expressive software

  • Blockchain assumptions

can be inverted

  • There is more room for

innovation than we think

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SLIDE 40

D O C U M E N T C O I N

C RY P T O C U R R E N C Y F O R T H E G I F T E C O N O M Y

Chris Anderson @jchris jchris@gmail.com QCon London 2016