Bitcoin Resilient or Vulnerable: Cambridge Study Reveals Critical Role of Submarine Cables

Since its launch in 2009, Bitcoin has operated nonstop for over a decade. However, one fundamental question remains empirically unanswered: what exactly is needed to disable the network? Researchers from the Cambridge Centre for Alternative Finance have just released a comprehensive study mapping Bitcoin’s physical vulnerabilities to infrastructure disruptions, with a particular focus on the role of submarine cables as the backbone of global connectivity.

This first longitudinal study analyzes 11 years of peer-to-peer network data against 68 verified submarine cable disruption events. The results challenge common assumptions about how Bitcoin can be compromised. Findings reveal that between 72% and 92% of intercontinental submarine cables must fail simultaneously before the network experiences significant node disconnection. This provides the first empirical benchmark for how difficult it truly is to deactivate Bitcoin’s infrastructure.

Two Threat Scenarios: Random vs. Coordinated

The most crucial finding of this research is the identification of a fundamental asymmetry between two very different threat models. Bitcoin’s resilience to random cable disruptions turns out to be much stronger than previously estimated.

The researchers ran 1,000 Monte Carlo simulations per scenario and found that random submarine cable failures have little impact on network operation. Over 87% of the 68 real-world disruption events studied caused impacts on fewer than 5% of nodes. Even the largest submarine disruption analyzed—when a seabed fault off Côte d’Ivoire in March 2024 damaged 7-8 cables simultaneously—only caused 43% of regional nodes to go offline, affecting just 5-7 Bitcoin nodes globally, which is about 0.03% of the network. Interestingly, the correlation between cable failures and Bitcoin price was essentially zero, at -0.02. Physical infrastructure disruptions are practically invisible compared to daily price volatility.

The situation changes drastically when threats are coordinated and targeted. Attacks aimed at submarine cables with the highest “betweenness centrality”—cables serving as bottlenecks between continents—lower the failure threshold to just 20%. Even more concerning, focused attacks on the top five hosting providers by number of nodes (Hetzner, OVH, Comcast, Amazon, and Google Cloud) require only a 5% removal of routing capacity to produce network shutdown effects.

This difference reflects two very different enemies: random failures are natural events that Bitcoin can withstand, while coordinated attacks represent man-made threats—whether from state actions, regulator-ordered service shutdowns, or deliberate cuts to critical cable routes.

Resilience Footprint: Evolution of Robustness Over Ten Years

This study also maps how network resilience has evolved since monitoring began. The trajectory is not a straight line but a fluctuating curve aligned with the geographic concentration of Bitcoin infrastructure.

Bitcoin shows the strongest resilience during 2014-2017, when the network was geographically dispersed with a critical failure threshold around 0.90-0.92. However, resilience sharply declined during 2018-2021 as the network grew rapidly but became geographically concentrated. The lowest point was reached in 2021 with a threshold of 0.72—when mining activity peaked in East Asia.

China’s mining ban in 2021 shifted the dynamics. The global redistribution of miners forced recalibration of strategies, and resilience partially recovered to 0.88 in 2022. However, latest data indicates the resilience threshold stabilized at 0.78 in 2025, suggesting the network has reached a new balance between growth and decentralization.

Unexpected Protection: How TOR Strengthens the Network

One of the most surprising findings of this study is the positive role played by The Onion Router (TOR) in enhancing Bitcoin’s physical resilience against submarine cable disruptions.

Conventional wisdom suggests that widespread TOR use might expose vulnerabilities. If TOR nodes are geographically concentrated, the old logic says, the network could be more vulnerable than it appears. But Cambridge’s findings are the opposite.

By 2025, 64% of Bitcoin nodes use TOR, hiding their physical locations. The researchers built a four-layer model to test this concern and found surprising results: TOR relay infrastructure is highly concentrated in Germany, France, and the Netherlands—countries with extensive submarine cable connectivity and land borders. For an attacker aiming to disrupt TOR relay capacity by cutting submarine cables, this layered infrastructure presents a complex challenge. These countries are the hardest to disconnect from global connectivity.

The four-layer model consistently shows higher resilience compared to a baseline of clearnet nodes alone, with TOR adding between 0.02 and 0.10 to the critical failure threshold. This phenomenon reflects what the researchers call “self-organizing adaptive resilience.” Adoption of TOR surged after a series of censorship events—2019 Iran internet shutdown, 2021 Myanmar coup, China’s mining ban. The Bitcoin community organically migrated toward censorship-resistant infrastructure, which not only enhances privacy but also physically fortifies the network against disruptions.

Real Threats: When Theory Meets Geopolitics

With the Strait of Hormuz effectively closed and regional conflicts disrupting infrastructure across the Middle East, the question of what would happen to Bitcoin if submarine cables were damaged is no longer purely theoretical. Cambridge’s study outlines two possible scenarios.

In the first—random disruptions or natural disasters—the Bitcoin network would likely survive. Massive disconnection thresholds of 72-92% are required to cause significant damage, a level of disruption highly unlikely to occur by accident.

In the second—coordinated attacks targeting critical points in submarine infrastructure or major hosting providers—Bitcoin faces credible risks but still requires substantial coordination and resources. Attackers would need the capability to simultaneously target specific geographic locations or isolate particular service providers. This is a state-level threat or highly coordinated regulatory interference scenario.

This study essentially maps the risk landscape for Bitcoin in unprecedented detail. The network proves more resilient to random infrastructure disruptions than feared, but it still has vulnerabilities exploitable through systematic attacks on submarine cables and key hosting infrastructure. The key to Bitcoin’s long-term resilience may lie in continued organic decentralization and the adoption of privacy-enhancing technologies like TOR, which inadvertently strengthen the physical robustness of the network.