Reimagining Onion Messages as an Overlay Layer

The discussion highlights several key points regarding the management and limitations of onion links within a network, specifically addressing concerns related to nuisance attacks and the structural integrity of the network through the use of minimum spanning trees (MSTs). Initially, it's noted that the potential for nuisance attacks is inherently limited by the 65 KB size restriction on node_announcement messages, effectively capping the number of onion links a node can advertise. This serves as a preventive measure against excessive storage demands per node.

Additionally, the creation of onion links incurs direct on-chain costs, serving as another deterrent against the proliferation of unnecessary links. To further mitigate potential issues, clients observing or implementing this overlay network can impose eligibility requirements for advertising an onion link. These requirements might include, but are not limited to, minimum channel sizes and a cap on the number of onion links per channel, ensuring that only nodes meeting specific criteria can participate in the dissemination of these links.

The conversation also explores the application of MST algorithms within this context, questioning their fragility and efficiency. Given their routine use in computer networking and their relatively efficient computational complexity (noted as $O(m \log n)$), the inquiry seeks to understand the perceived vulnerabilities of employing such algorithms for maintaining minimal graph structures in this domain. The algorithms' efficiency and established use case in similar scenarios suggest they could be effectively applied without introducing significant fragility.

Moreover, it's argued that nodes have considerable autonomy in defining constraints for how they construct their view of the network. This includes setting limits on the number of vertices to include in the MST, thereby avoiding unnecessarily expansive overlays with excessive links. Should these self-imposed constraints compromise network reachability, nodes retain the flexibility to adjust their parameters, such as increasing the threshold for included vertices, especially since they already possess the relevant data from node announcements.

In essence, the dialogue underscores a multifaceted approach to managing and safeguarding the network against potential overloads and security threats through strategic limitations on message sizes, economic disincentives, eligibility criteria for participation, and adaptable algorithmic solutions for network topology optimization.