Bitcoin Resilience Under the Microscope: The Impact of Infrastructure Failures on the Network

Since its launch in 2009, the Bitcoin network has been running uninterrupted, but the question of what it would cost to actually take it offline has only recently been thoroughly investigated. Researchers at the Cambridge Centre for Alternative Finance have published the first longitudinal study analyzing the resilience of the Bitcoin blockchain against disruptions to physical infrastructure. This research covers a period of eleven years of peer-to-peer network data and compares this data against 68 verified failures of undersea cables.

The key finding is that between 72% and 92% of intercontinental undersea cables would have to fail simultaneously to cause significant disconnections of Bitcoin nodes. In a world where the Strait of Hormuz is currently disrupted and infrastructure vulnerability is acutely apparent, this research provides an empirical measure of vulnerability. Bitcoin.

The figures paint a picture of a network that is gradually degrading rather than collapsing catastrophically. In 1.000 Monte Carlo simulations per scenario, the researchers concluded that random cable failures are barely noticeable. More than 87% of the 68 cable failures studied had less than a 5% impact on the nodes. The largest event occurred in March 2024, when seabed disturbances caused damage to 7-8 cables, disabling 43% of regional nodes but affecting only 5-7 Bitcoin nodes globally (approximately 0,03% of the network).

Interestingly, the correlation between cable outages and the price of Bitcoin is virtually nil, with a value of -0,02. This suggests that infrastructure disruption gets lost in daily price fluctuations.

Difference between Random and Targeted Attacks

The most significant finding of the study is the asymmetric nature of random failures and targeted attacks. While random cable failures require 72–92% removal to inflict damage, a targeted attack on cables with the highest inter-centrality—which act as bottlenecks between continents—reduces this percentage to just 20%. This points to an inherently different threat. Random failures are the result of nature, whereas targeted attacks often originate from governments coordinating host providers or deliberately disconnecting critical cable routes. The study thus clearly distinguishes between two different adversaries: one to which Bitcoin can adapt relatively easily, and another that poses a credible threat.

The study traces the evolution of Bitcoin's resilience over the years, and the progression is anything but linear. Bitcoin was most resilient in the early years from 2014 to 2017, when the network was geographically diverse and the critical failure threshold lay around 0,90–0,92. However, this resilience declined sharply between 2018 and 2021, when the network grew rapidly but became geographically concentrated, reaching a low of 0,72 in 2021, during the peak of mining concentration in East Asia. The Chinese mining ban of 2021 forced a redistribution, and resilience partially recovered to 0,88 in 2022, before stabilizing at 0,78 in 2025.

A remarkable finding is that 64% of Bitcoin nodes will use TOR in 2025, which makes their physical location invisible. The assumption was that this invisibility masked a fragility; if TOR nodes turned out to be geographically concentrated, the network might be more vulnerable than it appears. The Cambridge researchers developed a four-layer model to test this assumption and discovered the opposite. TOR relays are heavily concentrated in Germany, France and the Netherlands, countries with extensive undersea cable and land border connections. An attacker attempting to disrupt TOR relay capacity by cutting cables would face a challenge, as these countries are difficult to disconnect. The four-tier model consistently showed higher resilience than the clearnet-only baseline, with TOR adding between 0,02 and 0,10 to the critical failure threshold.

This research can be interpreted as “adaptive self-organization.” The adoption of TOR increased following censorship incidents such as the internet shutdown in Iran in 2019, the coup in Myanmar in 2021, and the Chinese mining ban. The Bitcoin community is shifting toward censorship-resistant infrastructure without central coordination, which has coincidentally contributed to making the network physically harder to disrupt. With the Strait of Hormuz effectively closed and regional conflicts disrupting infrastructure in the Middle East, the question of what happens to Bitcoin if undersea cables are damaged is more than theoretical. The conclusion of the study is that nothing likely happens, unless someone specifically attacks the cables and host providers that really matter.

Frequently Asked Questions

What are the key findings of the research into Bitcoin's resilience?
The research shows that between 72% and 92% of intercontinental undersea cables must fail simultaneously to cause significant node disconnection in Bitcoin. This points to the robust infrastructure of the network, which is resilient to random failures.

How do random disruptions differ from targeted attacks on the Bitcoin network?
Random failures require a high degree of infrastructure failure to cause damage, whereas targeted attacks on infrastructure bottlenecks need to have much less impact to achieve a similar result. This creates a different threat model for network security.

What does the adoption of TOR mean for the security of Bitcoin nodes?
The increased adoption of TOR makes the physical locations of many Bitcoin nodes invisible, making it more difficult for attackers to carry out targeted attacks. This increases the overall resilience of the network, especially in areas where physical decoupling is challenging.