The Bitcoin network has been running non-stop since 2009. The question that no one has rigorously answered until now is 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 disruption, analyzing 11 years of peer-to-peer network data against 68 verified undersea cable failure events.
The main finding is that between 72% and 92% of the undersea cables between countries in the world would have to fail simultaneously before Bitcoin would experience a significant disconnection of nodes.
In a world where the Strait of Hormuz is currently disrupted and infrastructure vulnerability is a priority, the study provides the first empirical benchmark of how difficult it really is to take Bitcoin offline.
The numbers tell the story of a network degrading gracefully rather than collapsing catastrophically. The researchers ran 1,000 Monte Carlo simulations per scenario on the entire data set and found that random cable failures are barely recorded.
More than 87% of the 68 real-world cable failure events they studied caused less than 5% impact to the nodes. The largest event, when seafloor disturbances off Ivory Coast damaged 7 to 8 cables simultaneously in March 2024, disabled 43% of regional nodes but affected only 5 to 7 bitcoin nodes globally, about 0.03% of the network.
The correlation between cable failures and the price of bitcoin was essentially zero, at -0.02. Infrastructure disruptions are invisible in the face of daily price volatility.
But the most important finding of the paper is the asymmetry between random and targeted attacks.
While random cable failures require between 72% and 92% removal to cause damage, an attack targeting the cables with the highest betweenness centrality, those that serve as choke points between continents, reduces that threshold to 20%.
And targeting the top five hosting providers by number of nodes—Hetzner, OVH, Comcast, Amazon, and Google Cloud—requires removing just 5% of routing capacity to achieve the same impact.
That’s a fundamentally different threat model. Random failures are acts of nature. Targeted attacks are acts of state, coordinated regulatory shutdowns of hosting providers, or deliberate outages of critical cable routes. Basically, the study maps two very different adversaries: one that Bitcoin can easily survive and another that remains a credible risk.
How threats to bitcoin change over time
The article traces how resilience evolved over time, and the trajectory is not a straight line. Bitcoin was most resilient in its early years, between 2014 and 2017, when the network was geographically diverse and the critical failure threshold was between 0.90 and 0.92.
Resilience decreased dramatically during 2018-2021 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 mining ban in 2021 forced redistribution and resilience partially recovered to 0.88 in 2022 before settling at 0.78 in 2025.
It is the TOR finding that challenges conventional thinking. As of 2025, 64% of Bitcoin nodes use TOR, making their physical location unobservable.
It has been assumed that this inability to observe could hide fragility, that if TOR nodes turned out 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 undersea cable connectivity and land borders.
An attacker attempting to disrupt TOR relay capability by cutting cables faces a complex problem because those countries are among the most difficult to disconnect. The four-layer model consistently showed greater resilience than the clearnet-only baseline, with TOR adding between 0.02 and 0.10 to the critical failure threshold.
The article frames this as “adaptive self-organization.” The adoption of TOR emerged after censorship events such as the 2019 Iran internet shutdown, the 2021 Myanmar coup, and China’s mining ban.
The Bitcoin community shifted toward a censorship-resistant infrastructure without any central coordination, and that shift also made the network physically harder 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 undersea cables are damaged is not theoretical.
The study suggests the answer is probably nothing, unless someone deliberately targets the specific cables and hosting providers that matter most.
