Blockchains as Economic/Digital Infrastructure
STAT 499
- trust
- decentralized
- proving things
- accountability
“corruption factor”
trust, but verify (trustlessness)
Trust relationships
social -> institutional -> programmable
- medium of exchange
- unit of account
- store of value
Bitcoin §
a prefix-immutable append-log of non-conflicting authenticated events in a decentralized peer-to-peer network
rules:
- prove ownership of balance when you try to spend it
- no transactions that result in you spending more than you have
- unit of value can only be spent once
fixed, full history
public ledger.
- everyone has a copy.
incentives for mining.
Primitives §
Asymmetric Cryptography §
digital signatures.
Signature = Sign(M, k)
Verify(M, Signature, K)
Hash functions: one-way functions. uniq.
“difficult to solve, easy to verify”
Proof of work
Blockchain §
every block includes the hash of the previous block
nakamoto consensus. longest chain wins
honest majority assumption
fault tolerance
probabilistic consensus
Ethereum §
General, as opposed to bitcoin
deterministic FSM
- mining loop
- ledger loop
ethereum virtual machine
decentralized applications. contracts.