- Distributed “database”
- No central authority
- Chain of blocks
- Each block has
- Previous block hash
- Distributed ledger
why do we need blockchain
- Digital Identity
- Intellectual Property / Notary
- Voting (?)
- Smart contracts!
- Removes trust from an entity
- Mathematically correct
- (Almost) impossible to fraud
Content Ownership / Copyright
How to use the blockchain to register some document as mine?
Proof-of-Work vs Proof-of-Stake
- TODO https://www.youtube.com/watch?v=M3EFi_POhps
- TODO Proof-of-replication ? https://filecoin.io/proof-of-replication.pdf
- TODO Powerful fault tolerance: https://filecoin.io/power-fault-tolerance.pdf
- 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.