SCOTTCOIN

NETWORK

TRANSACTIONS

MINING

NETWORK

PEER-TO-PEER NETWORKS

 

  • Establishing and maintaining a network of nodes without any central control and no existing trust
     
  • Napster solved this about 17 years ago
     
  • Like iTunes but...
    • Free as in beer
    • Dubious legality
    • Featured less U2

DISCOVERY

 

1. Start with a hard-coded list of peers

 

2. Connect to a random subset of known peers

 

3. Ask connected peers for their known peers

 

4. GOTO 2

PROPAGATION

 

1. Listen for incoming data from connected peers

 

2. If you're seen a piece of data before, ignore it

 

3. If not, broadcast it to all connected peers

 

4. GOTO 1

TRUST

 

1. Maintain a reputation score for each connected peer

 

2. Increment for each valid broadcast received

 

3. Decrement for each invalid broadcast received

 

4. If reputation falls below threshold, blacklist peer

THERE ARE NO GOOD "TRUST" PICTURES ON GOOGLE

NETWORK

  • Discovery of peers
  • Propagation of data
  • Trust in a trust-less world TM

TRANSACTIONS

WHAT IS A COIN?

SEQUENCE

SEQUENCE

THE COIN IS A LIE

OWNERSHIP

OBLIGATORY IMAGE OF PADLOCKS WHILST TALKING PUBLIC/PRIVATE KEY CRYPTO

MYTH

Coins are created during some kind of cryptographic voodoo ceremony which occurs during mining

FACT

Coins are created by mutual agreement of users.

 

The validation code run by nodes treats the first transaction in a block as an exception.

 

The inputs of the first transaction are not validated.

TRANSACTIONS

  • Coins are tokens
  • ScottCoins don't exist
  • Crypto isn't magic

MINING

WITH JENNY

IMAGE STOLEN, BUT THEN THE SONG WAS AWFUL, SO IT'S MORALLY LEGIT

BLOCKS

 

  • Blocks group together individual transactions
     
  • Blocks aren't conceptually important to blockchains
     
  • Transactions could be mined individually
     
  • An elegant hack to increase the transactions rate

CONSENSUS

SEQUENCE

CONSENSUS

PREVENTS
DOUBLE-SPENDING

MYTH

Proof of work is some kind of cryptographic witch-hunt to provide ultimate validation of a block

FACT

Proof of work could be any problem which is hard to compute but easy to verify.

 

It exists to artificially slow down the block creation time.

 

This permits time for the unreliable and slow network to come to a consensus.

MINING

  • Blocks don't matter
  • Mining allows consensus
  • Consensus prevents double-spending

CREDITS

ANDY & RICHARD

Jaime & James

ROB

SCOTTCOIN

<FIN>