BLS

Tries

governance token

• Gas optimization

  1. Minimize storage writes (SSTORE): memory for local computation within a function.
  2. Variables Packing
  3. external + calldata: 내부에서 실행되면 calldata의 값이 memory이 있을 수 있음. (그럼 memory데이터를 사용하는게 더 효율적). 그래서, 형식을 맞추거나 참조를 재설정하는 복잡한 과정이 추가됨.

• ETL(Extract - Transform - Load) Listens to blockchain nodes for new blocks and events. Decodes raw data (e.g., smart contract calls, token transfers) into meaningful records. Stores this structured data in a specialized database.

• 트랜잭션 및 기록 nonce 관리 - Noncemanager. Async Tx - success, fail(retry by order), timeout(replace).

  retry: 다른 논스, New 트랜잭션 (While revert, out of gas)

  replace: 같은 논스, 가스비 변경. TX Drop: 잔액 비교 후 다를 경우, 온체인 데이터로 최신화(변경). 순서 보장: blockNumber + transactionIndex

• Nonce conflict: pending tx를 조회해서 증가시킴. (Noncemanager가 하는일) and 메모리에서 관리함.

• Nonce gap: monitoring -> retry

• 네트워크 커넥션 실패 -> 논스 그대로 재전송

• 블록체인 실패(가스비orRequire) -> 가스비 증가 or require구문에 맞게 다시 요청.

• Keccak-256: Save data storage(public key is long), Quantum Resistance

• How to communicate other node for reaching stable consensus: Gossip network

• Nodes: full, archive(full+historical)

• PoS - committee(128 validators)

• latest block, safe block: 12 blocks, finalized block: 64 blocks = 64 slot = 2 epoch

• The journal contains **the list of state modifications applied since the last state commit. These are tracked to be able to be reverted in the case of an execution exception or request for reversal.

• Transactions Flow: 트랜잭션 생성 및 서명 → 서명 검증

  1. EOA: account
     • fields: nonce, balance, storageRoot, codeHash
       • storageRoot: Only C.A. fields 값(state variables)들의 루트값.
       • codeHash: Only C.A.
  2. 생성하는 법
     1. Transfer(EOA→TX→EOA)
     2. Execute smart contract(EOA→TX→CA)
     3. Deploy smart contract
  3. EVM: 트랜잭션 실행
     1. EVM 구조

        • storage: persistent data store(state variables)

          • storage layout: (key: $2^{256}$ slot, value: 한 slot당 32 bytes이하.)

            keccak(slotID): {
              { key: slotID, value: data length },
              { key: hashed slotID, value: data },
              { key: hashed slotID, value: data }
            }
            

            contract StorageExample {
              uint256 public x;                // Slot 0
              uint256[] public dynamicArray;   // Slot 1 (length stored here, elements at keccak256(1))
              mapping(uint256 => uint256) public map; // Hash-based storage
            
              struct MyStruct {
                uint128 a;
                uint128 b;
                uint256 c;
              }
            
              MyStruct public s;             // Starts at Slot 2
            }
            

        • memory: temporary data store(function parameters, local variables)

        • stack: opcode operation

        • calldata: read-only data

     2. 실행 후: world state 변경(status: pending)
  4. Broadcast pending txs to mempool of validator
     1. 어떻게 broadcast: P2P network의 wire protocol을 이용
     2. P2P network 형성
        1. UDP: bootnodes(detect and discover new nodes)와 PING-PONG
        2. TCP: RLPx protocol(establish connection for communication and encrypt message)
        3. TCP: Wire protocol(propagate pending transactions, blocks and synchronize states)
  5. Create and validate a block
     1. pending transaction을 포함하고, 블록을 검증 완료(status: success)
     2. validator는 누가?? PoS는 32ETH이상
  6. Propagate a block

• Log

  • LogsBloom: 256 bytes bloom filter summarizing all events.
  • Log Object
    • data: indexed가 아닌 인자값
    • topics: 1번째: 이벤트 서명 해시(e.g., keccak256(‘event(type)’)), 2번째~5번째: indexed인 인자값
  • Index: enables efficient and fast searching as well as historical token transfers.

• ECDSA

  • Signing

    Input: Random Integer, Hashed message, Private key

    Output: Signature (R, S)

  • Verifying

    Input: RecoveryId(v) Signature (R, S), Hashed message

    Output: Uncompressed ECC public key → hash → ethereum address(last 20bytes)

    match: Valid or Invalid

  • Elliptic Curve Cryptography(ECC) Public key

    uncompressed(prefix 04) => 65 bytes (0x + 04(1byte) + x(32bytes) + y(32bytes)

    • compressed and uncompressed?

      why compress? → Bitcoin, L2, P2P에서 사용.

      two times less space in memory by removing the y coordinate.

      prefix 02(y is even): 33 bytes, prefix 03(y is odd): 33 bytes

      x를 알면 y값을 알 수 있음. 그래서, 공개키를 구할 수 있음.