Blockchain

  • Distributed “database”
  • No central authority
  • Transparent
  • Chain of blocks
  • Each block has
    • Previous block hash
    • Hash
    • Data
  • Distributed ledger

why do we need blockchain

Applications

  • Digital Identity
  • Cryptocurrencies
  • Intellectual Property / Notary
    • stampd.io
  • Voting (?)
  • Smart contracts!

Cryptocurrencies

  • Removes trust from an entity
  • Mathematically correct
  • (Almost) impossible to fraud
  • Transparent

How to use the blockchain to register some document as mine?

Proof-of-Work vs Proof-of-Stake

Problems

  • Too much power usage
  • All nodes need to verify transactions –> slow as the slowest node

Proof of Work (PoW)

For example adding a random number to the end of the message that makes the hash function output 30 zeros in the beginning. That requires a lot of computational work to find out but it is easily verifiable.

References