The Bitcoin network has been running non-stop since 2009. The question that no one has rigorously answered so far is what would actually be needed to break it.
Researchers at the Cambridge Center for Alternative Finance last week released the first longitudinal study of the Bitcoin blockchain’s resilience to physical infrastructure disruptions, analyzing 11 years of peer-to-peer network data and 68 verified incidents of submarine cable failures.
The most important finding is that 72% to 92% of the world’s inter-country undersea cables would need to fail simultaneously before Bitcoin would experience a severe node outage.
In a world where the Strait of Hormuz is currently disrupted and infrastructure vulnerabilities are in the spotlight, this study provides the first empirical benchmark for the actual difficulty of Bitcoin offline.
The numbers tell a story of a smooth network degradation rather than a catastrophic collapse. The researchers ran 1,000 Monte Carlo simulations of each scenario across the entire data set and found that random cable failures were almost unrecorded.
Of the 68 real-world cable failure events they studied, more than 87% resulted in less than 5% node impact. The largest single event was a seafloor disturbance near Côte d’Ivoire in March 2024, which simultaneously damaged 7-8 cables and caused 43% of regional nodes to be paralyzed, but only affected 5-7 Bitcoin nodes globally, accounting for approximately 0.03% of the network.
The correlation between cable failures and Bitcoin prices is essentially zero at -0.02. Infrastructure disruptions are invisible in daily price fluctuations.
But the paper’s most important finding is the asymmetry between random and directed attacks.
While random cable failures would require removal of 72-92% to cause damage, a targeted attack on the cables with the highest betweenness centrality (choking points between continents) would lower the threshold to 20%.
For the top five hosting providers by node count (Hetzner, OVH, Comcast, Amazon, and Google Cloud), just removing 5% of routing capacity achieves the same effect.
This is a fundamentally different threat model. Random failures are a natural phenomenon. Targeted attacks are state actions, coordinated regulatory shutdowns of hosting providers, or deliberate severing of critical cable routes. The study essentially paints a picture of two distinct adversaries: one that Bitcoin can easily survive, and one that still presents a credible risk.
How threats to Bitcoin change over time
The paper tracks how resilience evolves over time, and the trajectory is not a straight line. Bitcoin was most resilient in its early stages from 2014 to 2017, when the network was widely distributed and the critical failure threshold was around 0.90-0.92.
During 2018-2021, as the network grew rapidly but was geographically concentrated, elasticity declined sharply, reaching a low of 0.72 during the peak of mining concentration in East Asia in 2021. China’s mining ban forced a reallocation in 2021, with the elasticity coefficient partially recovering to 0.88 in 2022 before stabilizing at 0.78 in 2025.
The discovery of TOR challenged conventional thinking. As of 2025, 64% of Bitcoin nodes use TOR, making their physical location unobservable.
The hypothesis is that this unobservable condition may hide vulnerabilities, and if TOR nodes are geographically concentrated, the network may be more vulnerable than it appears.
Cambridge researchers built a four-layer model to test this and found the opposite result. TOR relay infrastructure is concentrated in Germany, France, and the Netherlands, which have extensive undersea cable and land border connections.
Attackers trying to disrupt TOR’s relay capabilities by cutting cables face a complicated problem, as these countries are among the most difficult to disconnect. The four-layer model consistently exhibits higher resilience than the pure clearnet baseline, with TOR increasing the critical failure threshold by 0.02 to 0.10.
The paper describes this as “adaptive self-organization.” TOR adoption has surged following censorship incidents such as the 2019 Iranian internet shutdown, the 2021 Myanmar coup, and the Chinese mining ban.
The Bitcoin community moved to censorship-resistant infrastructure without any central coordination, and this shift also happened to make the network physically harder to breach.
With the Strait of Hormuz effectively closed and regional wars damaging infrastructure across the Middle East, the question of what would happen to Bitcoin if undersea cables were damaged is no longer a theoretical one.
Research suggests the answer is probably anything but that, unless someone deliberately targets specific cable and hosting providers that matter most.
