Are subsea cables the Achilles’ heel of the Internet?

Writer Samira Joineau
subsea cables internet enisa report

The latest report of the European Union Agency for Cybersecurity (ENISA) delves into the heart of the subsea cable ecosystem uncovering the vital role these undersea highways play in the global Internet infrastructure. Meanwhile, it has raised a poignant alarm. 

More than 97% of the world’s internet traffic flows through these submerged lifelines, a statistic that underscores their indispensable role in the modern world. Overall, subsea cables serve as the physical manifestation of our digital connections – linking distant shores, enabling real-time communication, and underpinning the global economy

Yet, as society’s reliance on the Internet is higher than ever before – and keeps growing exponentially – so does the spectrum of disruptions. ENISA’s report seeks to navigate the depths of this intricate ecosystem, revealing not only the role of subsea cables but also the intricate web of vulnerabilities that imperil their existence. 

The report underlines the vulnerabilities inherent in this vital infrastructure. Considering the Internet’s growing reliance and the ever-increasing volume of data transmitted, incidents involving subsea cables could lead to debilitating outages and disruptions. Among this sensitive ecosystem, weak points encompass the cable landing stations and subsea areas, where multiple cables converge. 

Last year, the International Cable Protection Committee’s report shed light on the causes behind most subsea cables incidents. Surprisingly enough, the majority of them are accidental, and are generally due to activities such as fishing or anchoring. Also, natural phenomena – such as underwater earthquakes and landslides – pose significant risks, especially in regions with a dense concentration of cables. In rare cases, system failures are responsible for incidents. 

However, the ENISA report’s most alarming aspect is the potential for malicious actions. Coordinated sabotage attacks on multiple cables simultaneously could plunge vast regions into digital darkness, revealing the fragile nature of our interconnected world. Repairing subsea cables is an intricate and time-consuming process, which relies on a handful of highly specialized cable repair ships worldwide. 

Besides, the threat of espionage lurks in the depths. While eavesdropping on cables on the seabed may seem unlikely, accessing communication data at the cable landing stations or at cable points could be a tangible threat that demands immediate attention. 

Key ENISA’s calls to action

Concretely, the report calls for: 

  • Comprehensive analysis of subsea cable resilience, redundancy, and capacity
  • Clarification of national mandates and supervision to protect cables, landing points, and prevent chokepoints vulnerabilities
  • Knowledge sharing among national authorities, including those experienced in protecting subsea power cables and critical infrastructure