Ethereum Wire Protocol (proposal for PV64 change)

Proposal (PV64)

GetProof [+0x11, [nodehash: B_32, key: B, blockhint: B_32 (optional)]] Require peer to return a Proof message, containing a Merkle-tree proof of the path starting from the node identified by nodehash, then following the nibbles found in order in key, until a leaf node or an empty node is found. The nodehash may be a root hash of a trie, or it may also be an intermediate node if the client already has some nodes of the required path downloaded. The accessed trie may be any of the tries referenced anywhere in the blockchain, including state, contract storage, transactions and receipts tries, and also intermediate states/storages. The optional blockhint parameter may specify a block that should be processed in order to find/re-generate the requested nodes. This allows full/archive nodes to discard intermediate states and re-generate them on demand.

Proof [+0x12, [node_1, node_2...]] Return a Merkle-tree proof consisting of a set of nodes that must be processed in order to access the trie entry value (or prove the absence of an entry) requested in GetProof