The Bitcoin network has been running non-stop since 2009. The question that no one had rigorously answered until now was what it would actually take to break it.
Researchers at the Cambridge Center for Alternative Finance last week published the first longitudinal study of the Bitcoin blockchain’s resilience to physical infrastructure disruptions, analyzing 11 years of peer-to-peer network data against 68 verified submarine cable failure events.
The main conclusion is that between 72% and 92% of the world’s inter-country submarine cables would need to fail simultaneously before Bitcoin experiences significant node disconnection.
In a world where the Strait of Hormuz is currently disrupted and infrastructure vulnerability is at the forefront, the study provides the first empirical reference point on how difficult it actually is to take Bitcoin offline.
The numbers tell the story of a network that is gradually deteriorating rather than catastrophically collapsing. The researchers ran 1,000 Monte Carlo simulations per scenario on the entire data set and found that random cable failures are barely registered.
More than 87% of the 68 real cable failure events studied caused less than 5% impact on nodes. The largest event, when seabed disturbances off the coast of Ivory Coast damaged 7-8 cables simultaneously in March 2024, destroyed 43% of regional nodes but affected only 5-7 Bitcoin nodes worldwide, or about 0.03% of the network.
The correlation between cable outages and the price of Bitcoin was virtually zero, at -0.02. Infrastructure disruptions are invisible in the face of daily price volatility.
But the study’s most important finding is the asymmetry between random and targeted attacks.
While random cable failures require 72-92% removal to cause damage, a targeted attack on cables with the highest centrality, those that serve as choke points between continents, lowers this threshold to 20%.
And targeting the top five hosting providers by node count, Hetzner, OVH, Comcast, Amazon, and Google Cloud, requires removing just 5% of routing capacity to achieve the same impact.
This is a fundamentally different threat model. Random failures are acts of nature. Targeted attacks are acts of state, coordinated regulatory shutdowns of hosting providers, or the deliberate cutting of critical cable routes. The study essentially identifies two very different adversaries: one Bitcoin can easily survive and another that remains a credible risk.
How threats to Bitcoin evolve over time
The paper tracks the evolution of resilience over time, and the trajectory is not a straight line. Bitcoin was most resilient during its early years, between 2014 and 2017, when the network was geographically diverse and the critical failure threshold was around 0.90 to 0.92.
Resilience declined sharply during the 2018-2021 period, as the network grew rapidly but became geographically concentrated, reaching its lowest point of 0.72 in 2021 during the peak of mining concentration in East Asia. China’s 2021 mining ban forced redistribution, and resilience partially recovered to 0.88 in 2022 before settling at 0.78 in 2025.
The discovery of TOR is one that challenges conventional thinking. By 2025, 64% of Bitcoin nodes use TOR, making their physical location unobservable.
The hypothesis was that this inability to observe could hide fragility and that if the TOR nodes were found to be geographically concentrated, the network could be more vulnerable than it appears.
The Cambridge researchers built a four-layer model to test this and found the opposite. TOR relay infrastructure is heavily concentrated in Germany, France and the Netherlands, countries with extensive connectivity via submarine cables and land borders.
An attacker who attempts to disrupt TOR’s relay capability by cutting cables faces a complex problem, as these countries are among the most difficult to disconnect. The four-layer model consistently showed higher resilience than the Clearnet-only baseline, with TOR adding between 0.02 and 0.10 to the critical failure threshold.
The paper describes this as “adaptive self-organization.” Adoption of the terms of reference increased after censorship events such as the 2019 Iran internet shutdown, the 2021 Myanmar coup, and the China mining ban.
The Bitcoin community has moved toward censorship-resistant infrastructure without any central coordination, and this shift has also made the network physically more difficult to disrupt.
With the Strait of Hormuz effectively closed and a regional war disrupting infrastructure across the Middle East, the question of what happens to Bitcoin if underwater cables are damaged is not theoretical.
The study suggests the answer is probably nothing, unless someone is deliberately targeting the specific cables and hosting providers that matter most.
