evm.md

EVM

• EVM: From Solidity to byte code, memory and storage

  • Solidity and viper EVM language which generates .bin and .abi
  • Transactions are not part of the world state or state tree
    • It will be part of the information that gets linked to the block header which is a summary of all transactions
  • Contract is the transaction with no address, and only data
  • Full-flow walkthrough

• Reversing Ethereum Smart Contracts to find out what's behind EVM bytecode (Devcon4)

• Blockchain / Crosschain / DeFi Bridge Design

• Ethereum/EVM Smart Contract Reverse Engineering & Disassembly - Blockchain Security #3

  • Bytecode
    • Loader code
      • Execute once to store runtime code
    • Runtime code
      • Can map bytecode to EVM assembly
      • Reconstruct the control flow graph
      • Runtime code entry point is the dispatcher function
        • Switch to the first four bytes of the transaction payload
        • Execute associated code with the given function signature
        • Signature Database - https://www.4byte.directory
        • Security Analysis Tool
          • https://github.com/pventuzelo/octopus
          • https://github.com/ConsenSys/mythril
          • https://github.com/crytic/rattle
          • https://www.ethervm.io
    • Swarm hash
      • Merkle tree hash to retrieve

• Bridge/ Crosschain Bridge/ Defi Bridge

  • Why?
    • Transaction fees
    • Block confirmation times
    • Liquidity Pool
  • CrossChain Protocol Stack
    • Application
      • Built on function
    • Function Call
      • Execution
    • Messaging
      • Verification
  • Ethereum Event
    • Event can be proven to come from certain blockchain
  • Hash Timelock Contracts (HTLC)
    • Trustless
    • Decentralized exchange can only trade for assets on same blockchain
    • Atomic Swaps

• Introduction to Atomic Swaps: Live Demo + Solidity Tutorial Of Hash Timelocked Contract (HTLC)

• SputnikVM: Rust Ethereum Virtual Machine Implementation

• Gossipsub - A gossip-based pub-sub protocol By Yiannis Psaras @ Paris P2P Festival #1

  • Floodsub -> RandomSub -> GossipSub
  • Eager push
  • Lazy pull
  • Peer scoring each node
  • Keep connection with the highest score
  • First message flood
  • Then adaptive, flood local mesh, lazy pull others
  • Backoff and prune based on score
  • Sybil Attack
  • Eclipse Attack
  • Cold Boot Attack
  • Covert flash Attack

• Gossipsub v1.1 - A scalable, extensible & hardened P2P PubSub Router protocol with David Dias

  • p2p pub-sub system
  • random sub
  • Peer excahnge on prune
  • Epidemic broadcast tree
  • Bitswap
  • Ambient discovery reduced by swapping
  • episub

• Demystifying libp2p Gossipsub: A Scalable and Extensible p2p Gossip Protocol by Raúl Kripalani

  • Ambient peer discovery
  • IHAVE gossip
  • IWHAT gossip