About Compact SPV proofs via block header commitments



Summary:

The community does not have an official definition of "SPV proof". SPV nodes trust that the most-work chain is valid based on economic arguments about the opportunity cost of mining invalid blocks. They use block headers as proofs to determine the most-work block connected to the genesis block or most recent checkpoint. Linear scanning of block headers can be avoided by using back-links, which reduces space usage. Sergio Lerner's definition of SPV proof is a sequence of bits that can be transmitted as part of a non-interactive protocol that convincingly establishes for a client without access to the block chain that a block B is part of the best-chain. Mark Friedenbach's definition is a sequence of bits that can be transmitted as part of a non-interactive protocol that convincingly establishes for a client without access to the block chain that for some block B, B has an ancestor A at some specified height and work distance back, and the cost of creating a false proof is at least as much work as it claims to represent. The Satoshi whitepaper and BitcoinJ work according to the definition given by Mark Friedenbach.


Updated on: 2023-06-08T21:48:18.062653+00:00