EPFsg - Week 2

Block validation

• The consensus layer communicates with execution layer through a function defined in the consensus spec as process_execution_payload which does a series of checks and calls internally notify_new_payload, that will notify the execution engine of a new payload that needs to be processed

• The execution client then, runs the state transition function

  • If headers are invalid the block is rejected
  • If the transaction is invalid the block is rejected
  • If block and transactions are valid, the is state is updated

Block building

• Nodes are always gossiping transactions over the p2p network. These transactions form the mempool
• These transactions are valid to be included in a block: nonce in correct, account has enough balance to pay for the tx
• In summary, the building process should return a new block and the updated state or an error in case something goes wrong while building the block
• In the video this is note explicit, but in Ethereum the process of block building doesn’t happen at protocol level. External entities are responsible for block building and relaying those blocks to the block producers, aka validators