Bitcoin could withstand 72% of global submarine cable outages, but an attack on five key hosting providers might severely disrupt the network.

A new study from the Cambridge Centre for Alternative Finance suggests that Bitcoin is far more resilient to physical infrastructure failures than previously assumed, with the growing use of Tor actually strengthening the network’s durability.

Bitcoin has operated continuously since its launch in 2009, but until recently there had been little rigorous research into what kind of real-world disruptions could seriously damage the system.

Researchers at Cambridge conducted the first long-term study of the network’s physical resilience, comparing 11 years of peer-to-peer data with 68 verified submarine cable failures around the world.

Their findings indicate that between 72% and 92% of global inter-country submarine cables would need to fail simultaneously before Bitcoin nodes begin to disconnect at scale.

At a time when infrastructure vulnerabilities are drawing renewed attention — particularly amid disruptions around the Strait of Hormuz — the research provides the first empirical benchmark for how difficult it would be to knock the Bitcoin network offline.

Random disruptions have limited impact

The data suggests the network tends to degrade gradually rather than collapse suddenly.

Researchers ran 1,000 Monte Carlo simulations for each scenario and found that random cable failures have minimal impact. More than 87% of the 68 real-world cable faults examined affected fewer than 5% of nodes.

The largest incident occurred in March 2024, when seabed disturbances near Côte d’Ivoire damaged seven to eight submarine cables. While the disruption temporarily disabled about 43% of nodes in the region, only five to seven Bitcoin nodes worldwide were affected—around 0.03% of the network.

The study also found almost no relationship between infrastructure outages and Bitcoin’s price, with a correlation coefficient of roughly -0.02, indicating such events are largely invisible against normal market volatility.

Targeted attacks present a different risk

The research highlights a sharp contrast between random failures and deliberate attacks.

While random disruptions would require the loss of roughly three-quarters of global submarine cables to cause serious damage, a targeted attack on cables with the highest “betweenness centrality”—key routes that connect continents—could reduce that threshold to around 20%.

An even more concentrated threat involves hosting infrastructure. According to the study, targeting just five major hosting providers — Hetzner, OVH, Comcast, Amazon Web Services, and Google Cloud — could produce similar disruption with the removal of only about 5% of routing capacity.

This distinction points to two very different threat models. Natural failures such as cable breaks pose little systemic risk, while coordinated actions—such as state-led infrastructure targeting or regulatory shutdowns of hosting providers—could present a more credible challenge.

Resilience has shifted over time

The researchers also tracked how Bitcoin’s resilience has evolved.

The network was most robust between 2014 and 2017, when nodes were widely distributed geographically and the critical failure threshold reached about 0.90–0.92.

Resilience declined between 2018 and 2021 as rapid growth led to geographic concentration, particularly during the peak of mining activity in East Asia. The vulnerability threshold fell to around 0.72 in 2021.

After the government of China imposed a sweeping mining ban that year, miners and nodes redistributed globally. The network’s resilience partially recovered to about 0.88 in 2022 before settling near 0.78 by 2025.

TOR adoption improves network strength

One of the study’s most surprising conclusions relates to the role of Tor.

By 2025, about 64% of Bitcoin nodes operate through Tor, obscuring their physical location. Some observers previously feared this could hide geographic concentration and increase vulnerability.

However, the Cambridge team’s four-layer network model found the opposite effect.

Tor relay infrastructure is concentrated in highly connected countries such as Germany, France, and Netherlands — regions with extensive submarine cable networks and cross-border connectivity.

Because these areas are particularly difficult to isolate, disrupting Tor infrastructure through cable cuts becomes significantly more complex. The model showed Tor increased the network’s resilience threshold by 0.02 to 0.10 compared with a standard clearnet-only network.

Researchers describe this process as “adaptive self-organization.”

Tor adoption accelerated after major censorship events, including 2019 Iranian Internet shutdown, the 2021 Myanmar coup, and China’s mining ban.

Without centralized coordination, the Bitcoin ecosystem gradually shifted toward more censorship-resistant infrastructure—changes that also made the network physically harder to disrupt.

With geopolitical tensions and infrastructure risks rising across key shipping lanes such as the Strait of Hormuz, the question of whether submarine cable damage could affect Bitcoin is no longer purely theoretical.

The study suggests the network would likely continue functioning unless an attacker deliberately targeted the specific cables and hosting providers that serve as critical global chokepoints.