A Cambridge University study spanning eleven years of Bitcoin network data has found that undersea cable failures have historically triggered only minimal effects. Researchers Wenbin Wu and Alexander Neumueller examined eight million node observations, 658 cables, and 385 fault events between 2014 and 2025. Only 68 of those faults coincided with network disruptions. In 87% of cases, the change in node count remained below 5%, with an average impact of -1.5% and a median of -0.4%. No significant link appeared between node outages and Bitcoin price fluctuations.
Undersea Cable Threats Overstated
The study breaks down the Bitcoin network into three tiers: submarine cables for physical connectivity, autonomous systems (AS) for routing, and the peer-to-peer Bitcoin protocol on top. In a random cable failure scenario, disabling 72% to 92% of all cables would be needed to affect more than 10% of nodes. However, a targeted attack on hosting networks with dense node populations could cause far greater disruption. The Cambridge model indicates that even a 5% capacity reduction in the largest AS providers — including Hetzner, OVHcloud, Comcast, Amazon Web Services, and Google Cloud — could sharply reduce node connectivity.
Cloud Providers Are the Real Achilles' Heel
While geopolitical fears often focus on submarine cables, Bitcoin's true vulnerability lies in the dominance of major cloud hosting providers. Disruptions or regulatory actions targeting services like AWS or Google Cloud could visibly shrink the accessible node population. Still, off-protocol services such as the Blockstream satellite network and block relay networks continue to bolster the network's resilience.
Tor Network: From Privacy Tool to Infrastructure Layer
Bitcoin's node composition has shifted dramatically. In 2014, nearly no nodes ran over Tor; by 2021 the share jumped to 23%, soared to 52% in 2022, and reached 63.1% in March 2026. This surge coincided with events like Iran's 2019 communications blackout, Myanmar's 2021 coup, and China's 2021 Bitcoin mining ban. Originally valued for privacy, Tor now serves as a core structural resilience layer for Bitcoin. Though many node locations remain hidden, Tor relies on distributed servers primarily in well-connected countries like Germany, France, and the Netherlands. Expanding the model to include Tor relay infrastructure, researchers found that thresholds for a critical shutdown are dramatically higher. To disrupt both the open internet and Tor simultaneously would require a massive loss of connectivity infrastructure.
China's Ban Deepens Network Distribution
Bitcoin's infrastructural resilience hit its lowest point in 2021, when 74% of global mining power was concentrated in East Asia. After China's 2022 mining ban, geographic distribution widened sharply and Tor usage spiked. This shift significantly strengthened the overall durability of the Bitcoin ecosystem.