The world of cryptocurrency is a complex and ever-evolving landscape, and Bitcoin, the pioneer of digital currencies, is no exception. A recent study by researchers at the Cambridge Centre for Alternative Finance has shed light on the network's resilience to physical infrastructure disruptions, specifically focusing on submarine cable failures. The findings are both fascinating and crucial for understanding the potential vulnerabilities of Bitcoin's backbone.
A Resilient Network
The study, spanning 11 years and analyzing 68 verified cable failures, reveals that Bitcoin's physical infrastructure is more resilient than previously thought. The headline finding 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. This means that the network can withstand a high degree of physical disruption without experiencing catastrophic failures.
The researchers' Monte Carlo simulations further emphasize this point, showing that random cable failures have minimal impact. Over 87% of the studied cable fault events caused less than 5% node impact, and the largest single event affected only 5-7 Bitcoin nodes globally, which is a tiny fraction of the network.
This resilience is particularly intriguing when considering the Strait of Hormuz, a critical chokepoint for global trade. The study provides empirical evidence that Bitcoin's network degrades gracefully rather than collapsing catastrophically, even in the face of significant infrastructure disruptions.
Targeted Attacks: A Different Threat Model
However, the study also highlights a critical distinction between random and targeted attacks. While random cable failures require a high percentage of cable removal to cause damage, a targeted attack on the cables with the highest betweenness centrality (chokepoints between continents) drops that threshold to 20%.
The real concern arises when considering the top five hosting providers by node count: Hetzner, OVH, Comcast, Amazon, and Google Cloud. A targeted attack on these providers, which serve as critical nodes in the Bitcoin network, requires removing just 5% of routing capacity to achieve a significant impact. This threat model is fundamentally different from random failures, as it involves deliberate and coordinated actions by adversaries.
Evolving Resilience Over Time
The study also tracks how Bitcoin's resilience has evolved over time. The network was most resilient in its early years (2014-2017) due to its geographically diverse nature. However, as the network grew and concentrated geographically, resilience declined. The lowest point was reached in 2021 during peak mining concentration in East Asia, with a resilience score of 0.72.
The introduction of the China mining ban in 2021 forced a redistribution of mining activities, and resilience partially recovered to 0.88 in 2022. As of 2025, the resilience score has settled at 0.78, indicating a more concentrated network.
The Role of TOR
One of the most intriguing findings is related to the Tor network. The assumption has been that Tor's inability to observe physical locations might hide fragility, making the network more vulnerable. However, the study challenges this conventional thinking.
The researchers built a four-layer model and found that Tor relay infrastructure is heavily concentrated in Germany, France, and the Netherlands, countries with extensive submarine cable and land border connectivity. This concentration actually makes Tor nodes more resilient, as an attacker would face a compound problem when trying to disrupt Tor relay capacity by cutting cables.
This phenomenon is described as 'adaptive self-organization,' where the Bitcoin community has shifted towards censorship-resistant infrastructure without central coordination. This shift has inadvertently made the network physically harder to disrupt.
Implications for the Future
With the Strait of Hormuz effectively closed and a regional war disrupting infrastructure across the Middle East, the study's findings take on even greater significance. The question of what happens to Bitcoin if submarine cables get damaged is no longer theoretical but a pressing concern.
The study suggests that Bitcoin's network can withstand random failures and even targeted attacks on hosting providers, as long as they are not deliberately targeting the specific cables and providers that matter most. This resilience is a testament to the network's design and the community's efforts to build a robust and censorship-resistant system.
In conclusion, this study provides valuable insights into Bitcoin's resilience and highlights the importance of understanding the network's vulnerabilities. While the network can withstand significant physical disruptions, targeted attacks on critical hosting providers remain a credible risk. As the cryptocurrency landscape continues to evolve, ongoing research and analysis will be crucial in ensuring the long-term stability and security of Bitcoin and other digital currencies.
