Bitcoin will withstand breaks of almost all submarine cables, but it remains vulnerable to targeted attacks

Cambridge Study: Bitcoin Withstands Submarine Cable Failures but Is Not Protected Against Targeted Attacks

What the study showed
* Random failures

- When submarine cables are randomly disconnected, the Bitcoin network remains largely untouched.

- To cripple a significant portion of the network, one must simultaneously cut 72 % to 92 % of all global cables.

* Targeted attacks

- The network is vulnerable to attacks on key routing domains.

- Destroying the five largest nodes (Hetzner, OVH, Comcast, Amazon, and Google Cloud) could completely paralyze Bitcoin.

How the study was conducted
1. Data – 11 years of P2P‑network traffic + 68 confirmed cable damage incidents.

2. Model – Buldyrev cascade model applied to highly interdependent systems (computer networks, power grids, transport).

3. Result – a failure threshold in the range of 72–92 % for random failures.

Role of Tor
* The Tor protocol enhances Bitcoin’s resilience by making it harder to shut down due to regulatory pressure.

* However, against targeted attacks on major infrastructure nodes, Tor does not provide protection.

Conclusions and relevance
- Random submarine cable damage is “not scary” for Bitcoin; the network is resilient to widespread outages.

- Vulnerability to targeted attacks remains critical: a limited number of large nodes make the system fragile.

Recent incidents in the Baltic Sea, the Middle East, and the Taiwan Strait underscore the need for further study and strengthening of infrastructure.