In the continuing series “Edge Cases: The Metanet Blog,” nChain researcher Jack Davies broke down the nodes an edges that make up the Metanet DAG and how the Metanet protocol can be used to create on-chain DAG structures that can facilitate a peer-to-peer value network on Bitcoin SV.
Having previously explained what a directed acyclic graph (DAG) is and why the Metanet is a form of DAG, Davies delved into the Metanet nodes and their unique structure, as well as their unique identifiers. A Metanet node is a transaction that follows the rule set of the Metanet protocol.
For a transaction to qualify as a Metanet node, it must have at least one OP_RETURN output and an input signed by a parent node, denoted by SigP (parent). The node contains six elements, four of which are crucial. These are the address of the node, the version of a node, the address of the parent of the node and the version of the parent. The first two elements — denoted as P(node) and TxID(node) — are used to uniquely identify a node while the latter two — denoted as P(parent) and TxID(parent) are used to identify the parent of the node, if it has one.
The Metanet edges, on the other hand, are created by signatures. This means that to create an edge from a parent node to a child node, the latter must be signed using the key pair associated with its parent. In simpler terms, SigP (parent) must appear in the input of the child node.
The nodes and edges are crucial in the Metanet protocol, Davies explained.
The crucial aspect here is that the Metanet protocol leverages the input signatures and requires that they include signatures from the parent node to enforce permissioning structure on the Metanet graph.