Exam (elaborations) CCS339

1. Network Layer (Infrastructure Layer) Function: This layer handles peer-to-peer communication between nodes. Components: Node discovery Data propagation Transaction and block distribution Protocols: Gossip protocol, TCP/IP, etc. Goal: Ensure decentralized and secure data sharing between participants. 2. Data Layer (Storage Layer) Function: Manages how data is structured and stored. Components: Ledger structure (block, chain) Data formats (transactions, headers) Hashing (e.g., SHA-256) Merkle trees (for efficient and secure data verification) Goal: Provide an immutable and tamper-proof record of transactions. 3. Consensus Layer Function: Ensures all nodes agree on the state of the blockchain. Common Algorithms: Proof of Work (PoW) – Used by Bitcoin Proof of Stake (PoS) – Used by Ethereum 2.0, Cardano Delegated Proof of Stake (DPoS) – Used by EOS PBFT (Practical Byzantine Fault Tolerance) – Used by Hyperledger Goal: Prevent double-spending and maintain consistency across the network. 4. Execution Layer (Smart Contract Layer) Function: Executes smart contracts and transaction logic. Components: Virtual machines (e.g., Ethereum Virtual Machine) Contract compilers State machines Goal: Enable programmable logic that automatically executes based on predefined rules. 5. Application Layer Function: Interfaces with end-users and other applications. Examples: Decentralized applications (dApps) Wallets Web interfaces (e.g., MetaMask, Uniswap) Goal: Provide user interaction and external integration.