Byzantine Faults? Byzantine Fault Tolerance

Problems:

• Forgery: Sign transactions.

• Double Spending: Ledger. Nodes verify each block to check for double spending?

• Theft:

Transaction: <destination-public>, <transaction-id>, <source-signature>

Solutions:

• Forgery: Assumes participants keep their private key secure. Signature can verify transactions
• Double Spending: Public Log is required to check if the referred source transaction of bitcoin is not used twice
  • Consensus is required to agree upon a common history of transactions. Consistency is required

Approach for Consensus: 1. Centralized Server: Byzantine Fault 2. Centralized server only to store logs: server might provide different view of logs to different clients

Bootstrapping problem

What is selfish mining?

How is PoS better than PoW?

• Rich gets richer?