The Baltic Sea importance grows for many reasons. Trade and transport seem to be the most obvious of them. But beneath its relatively shallow waters lies a complex, invisible nervous system of submarine fiber-optic cables and energy interconnectors that keep Northern and Eastern Europe online, powered, and secure.

pic. Pixabay

The danger lurks in the bottom

Recent years’ events have demonstrated that the infrastructure on the bottom of the Baltic Sea is vulnerable. Between 2023 and 2025, several mysterious severings of critical subsea links have occurred, including the Balticonnector and the C-Lion1. These physical cuts have been a disruption of service, but there is a different threat that looms over the fiberoptical cables. Espionage and siphoning of data.
The web of lines on the Baltic’s bottom transfers loads of data every second and the shallow waters make them an easy prey for anybody looking to abuse this fragile system. Excavating data from the cables might not yield immediate results but could bring profits in the future. This is the so-called “harvest now, decrypt later” strategy. Hackers, sometimes state-sponsored, are stealing vast amounts of data today, such as financial transactions or even military communications, for future use. Once the quantum computing arrives, they will be able to crack open information packages that are encrypted with current standards.
When will this time arrive? It’s hard to say but the global powerhouses of tech such as China, Canada, U.S. and France are already preparing for it by political action or immense investments. What’s the way to protect the lifelines of the Baltic Sea?

pic. Pixabay

Let’s get physical

Traditional digital security relies on complex mathematics, assuming that certain equations are simply too difficult for current computers to solve. Quantum Key Distribution (QKD) takes a different approach by using the laws of physics to protect data. Rather than encrypting the message itself, this technology generates and shares a random, secret encryption key between a sender and a receiver.

The system transmits this key using individual photons of light sent over standard fiber-optic cables. Information is encoded into quantum states, allowing photons to exist in multiple states at once until they are measured. Even if somebody would try to intercept the photons as they travel through the cable, their state inevitably changes. According to laws of physics a person cannot observe a quantum system without altering it, and it is physically impossible to create an exact copy of an unknown quantum state.
In the end, the sender and receiver compare a small portion of their generated key to check for an error rate. If the errors exceed a specific threshold, they know the channel is compromised. The key is then discarded before any sensitive information is encrypted or transmitted.

Because this technology requires specialized hardware and dedicated optical connections, it is built for high-stakes infrastructure rather than personal computing. For distances where fiber-optic signals naturally degrade, the technology utilizes satellites as trusted relay nodes to bounce the quantum keys between distant ground stations.

While this physics-based method provides a verifiable level of security, it is rarely used alone. Infrastructure operators typically deploy it alongside classical encryption and software-based post-quantum cryptography, creating a layered defense system for their networks.

Q-Con and the Baltic Dual-Use Hackathon

The quantum era is no longer a sci-fi concept confined to laboratories. It is a pressing geopolitical reality that requires immediate action. And the solutions are being built right here in Gdańsk.

This September 11–13, 2026, the University of Gdańsk will host two major, intertwined events aimed at turning quantum theory into deployable defense and infrastructure solutions:

Q-Con 2026: The largest business-focused quantum technologies conference in Central and Eastern Europe. Join industry leaders, policymakers, and cybersecurity experts as they discuss the deployment of PQC and QKD across European critical infrastructure.

The Baltic Dual-Use Hackathon: Operating alongside Q-Con, this 48-hour innovation sprint invites engineers, startups, and researchers to build rapid prototypes solving real-world challenges in AI, drones, space, and quantum tech.

If we are to secure the Baltic Sea for the next century, we need the brightest minds working across academia, business, and the public sector. The quantum clock is ticking.