Bitcoin’s network has been running continuously since 2009. The question that no one had 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 overall finding is that between 72% and 92% of the world’s submarine cables between countries would have to fail simultaneously before Bitcoin experiences significant node disruption.
In a world where the Strait of Hormuz is currently disrupted and infrastructure vulnerability is on the horizon, the study provides the first empirical benchmark of how difficult Bitcoin actually is to knock offline.
The numbers tell a story of a network that degrades gracefully rather than collapsing catastrophically. The researchers ran 1,000 Monte Carlo simulations per scenario across the full data set and found that random cable failures are almost undetected.
Over 87% of the 68 real-world cable failure events they studied caused less than 5% node impact. The largest single event, when seabed disturbances off Côte d’Ivoire damaged 7-8 cables simultaneously in March 2024, knocked out 43% of regional nodes but only affected 5-7 bitcoin nodes globally, about 0.03% of the network.
The correlation between cable failure and bitcoin price was essentially zero at -0.02. Infrastructure disruptions are invisible to daily price volatility.
But the paper’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 the cables with the highest between-cable centrality, those that serve as choke points between continents, drops this threshold to 20%.
And targeting the top five hosting providers by node count, Hetzner, OVH, Comcast, Amazon and Google Cloud, requires removing only 5% of routing capacity to achieve the same effect.
It is a fundamentally different threat model. Random errors are acts of nature. Targeted attacks are state actions, coordinated regulatory shutdowns of hosting providers, or deliberate severing of critical cable routes. The study essentially maps two very different adversaries: one Bitcoin can easily survive, and one that remains a credible risk.
How threats to bitcoin change over time
The paper traces how resilience developed over time, and the trajectory is not a straight line. Bitcoin was most robust in the early years from 2014-2017 when the network was geographically diverse and the critical error threshold was around 0.90-0.92.
Resilience declined sharply during 2018-2021 as the network grew rapidly but concentrated geographically, reaching its lowest point of 0.72 in 2021 during peak mining in East Asia. The mining ban in China in 2021 forced reallocation and resilience partially recovered to 0.88 in 2022 before settling at 0.78 in 2025.
The TOR discovery is what challenges conventional thinking. As of 2025, 64% of Bitcoin nodes use TOR, making their physical location unobservable.
The assumption has been that this inability to observe could hide fragility, that if 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. The TOR relay infrastructure is heavily concentrated in Germany, France and the Netherlands, countries with extensive submarine cable and land border connections.
An attacker trying to disrupt TOR relay capacity by cutting cables faces a compounding problem because these countries are among the most difficult to disrupt. 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 error threshold.
The paper refers to this as “adaptive self-organization.” TOR adoption increased following censorship events such as Iran’s 2019 internet shutdown, the 2021 Myanmar coup, and China’s mining ban.
The Bitcoin community shifted towards 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 throughout the Middle East, the question of what happens to Bitcoin if the submarine cables are damaged is not theoretical.
The study suggests that the answer is probably nothing, unless someone deliberately targets the specific cables and hosting providers that matter most.
