I just finished reading an interesting study from Cambridge about Bitcoin infrastructure security. For years, people have said that Bitcoin is vulnerable due to submarine cable failures, but real-world data tells a completely different story.

Cambridge’s research team analyzed 11 years of Bitcoin network data along with 68 verified submarine cable cut incidents. The result: 87% of these incidents caused less than 5% node changes, with an average impact of only -1.5%, and almost no correlation with Bitcoin’s price. Imagine this a bit: to cause a real disruption, you would need to remove 72 to 92% of all international cables—something nearly impossible due to natural disasters or random failures.

But here’s the interesting part: the real weakness isn’t at the bottom of the ocean. It’s with cloud service providers. Targeting top autonomous systems like (ASN) such as Hetzner, AWS, Google Cloud, or OVHcloud, removing just 5% of routing capacity is enough to cause significant disruption. By March 2026, Hetzner manages 869 nodes, Comcast and OVH each have 348, Amazon 336, and Google 313— all these nodes rely on centralized data centers.

However, there’s an unexpected layer of protection: Tor. Usage of Tor has increased from nearly 0% in 2014 to 63% now. Most Bitcoin nodes today run over Tor, and these Tor relays are distributed across Germany, France, the Netherlands—countries with very good cable connectivity. As a result, the threshold for causing disruption rises significantly when considering this Tor layer.

What’s interesting here is that the centralization of cloud services isn’t a flaw of Bitcoin itself, but a consequence of external censorship pressures. When China bans mining, when Iran cuts off the Internet, when Myanmar has a coup—node operators automatically switch to censorship-resistant infrastructure without coordination. The network self-organizes and adapts.

Compared to the image of submarine cables being cut at the ocean floor, which critics like to mention, the actual risk is lighter but more specific: coordinated actions from a few service providers. But even if that happens, most nodes still operate thanks to Tor. Bitcoin isn’t as fragile as it seems, but it’s also not entirely independent of the real-world infrastructure.