A report published February 7 and authored in part by Blockstream researcher Christian Decker found that the BTC Lightning Network is “evolving towards an increasingly centralised architecture.” Proponents of LN say this is not a problem, and even critics of the network point to the necessity of properly defining — and not deifying — “decentralization.” Still, real concerns are presented with the new information, and some are looking to alternative solutions like Drivechain to fill the gap.
The report, entitled “Lightning Network: a second path towards centralisation of the Bitcoin economy,” states at outset that “despite the huge activity characterising the BLN, the bitcoins distribution is very unequal.” The paper elaborates: “the average Gini coefficient of the node strengths (computed across the entire history of the Bitcoin Lightning Network) is, in fact, ≃ 0.88 causing the 10% (50%) of the nodes to hold the 80% (99%) of the bitcoins at stake in the BLN (on average, across the entire period).”
While the Gini coefficient is typically used to measure income inequality, it is applied in the report as a means to determine relative centralization of Lightning. This type of metric for measuring centralization and decentralization, however, is criticized by some in the space as being inaccurate to the meanings of the terms as they pertain to bitcoin. Nevertheless the report details the continued emergence of centralized core-periphery structures, which some say make the network more vulnerable to attack.
While the complex math and methodology are laid out in detail in the paper, the group of researchers ultimately concludes:
In particular, its structure seems to become increasingly similar to a core-periphery one, with well-connected nodes clustering together (as revealed by the study of the eigenvector centrality). More precisely, our analysis reveals the presence of many star-like sub-structures with the role of centers played by the hubs,