What is Cybersecurity?

By the time you finish reading this article, between 15 and 20 cyberattacks will have taken place. Information is power. Today, most of it exists in digital form. As data moves through networks, sits on servers, and travels between devices, it needs protection. That’s where cybersecurity comes in.

But it goes far beyond files and passwords. As societies grow more connected, cyberattacks no longer stop at screens. They can spill into the physical world. A malicious programme can sabotage nuclear centrifuges. A data breach can cost close to $5 million. A ransomware attack on a hospital can disrupt patient care. Meanwhile, cybercriminals are adopting new technologies to strike faster and smarter, making cybersecurity one of the defining challenges of the digital age.

SnT researchers are on the front line — working with industry and government to turn the tide against attackers who grow more relentless and harder to anticipate.

1. What does everyday Cybersecurity look like?

Most people encounter Cybersecurity every day, often without noticing it: a prompt to update a password, a two-step login, a warning that a website is not secure. These are visible signs of a much larger system working in the background.

Cybersecurity refers to technologies, processes and policies that protect digital systems, networks, devices, and data from attacks, damage or unauthorised access. It aims to:

Keep sensitive information private
Protect critical infrastructure
Ensure businesses operate without disruption
Reduce risks to national security
Build trust in a digital society

2. Timeline: How Cybersecurity evolved

“I’M THE CREEPER: CATCH ME IF YOU CAN”. This taunting message appeared in 1971 on infected computers across ARPANET, a precursor to the internet. Behind it was Creeper, the first computer virus, created as a playful experiment. To hunt it down, Ray Tomlinson developed Reaper, the first antivirus programme. The cyber cat-and-mouse game had begun.

In 1986, Brain became the first virus to infect IBM personal computers via floppy disks. The threat prompted the development of the first commercial antivirus software. Two years later, Robert Morris accidentally spread a worm to around 6,000 internet-connected computers, earning him the first felony conviction under the US Computer Fraud and Abuse Act.

By the late 1990s, the rapid growth of e-commerce created a new problem: how to protect online transactions. SSL (Secure Sockets Layer), a protocol that encrypts data exchanged between a browser and a server, became the standard solution.

The 2000s brought a wave of damaging attacks. Malicious programmes such as ILOVEYOU, Code Red, and Sasser pushed organisations to strengthen defences with firewalls and encryption. Governments also began introducing cybersecurity regulations and policies, such as the US Homeland Security Act of 2002.

Nations soon became targets too.

In 2010, Stuxnet marked a turning point. Designed to sabotage Iran’s nuclear centrifuges, this worm was the first cyberattack to cause physical damage.

Today, billions of connected devices have vastly expanded the surface hackers can target. In response, zero-trust architecture has emerged as a security standard, based on one principle: never trust, always verify — even users already inside a network.

At the same time, new technologies such as artificial intelligence are turbocharging a race that shows no sign of slowing down.

3. How Cybersecurity works

Cybersecurity protects against common threats such as:

malware: malicious software designed to damage or infiltrate a system
ransomware: malware that locks victims out of their own data until they pay a ransom
phishing: fake messages to trick users into handing over sensitive information
social engineering: the act of manipulating people into revealing confidential data
denial-of-service: an attack that overloads a system with fraudulent requests to make a digital resource unavailable

To hold these threats at bay, organisations rely on a range of tools and practices, including firewalls, encryption, antivirus software, intrusion detection systems, zero-trust architecture, and secure communication protocols.

Five key layers of Cybersecurity

Think of a bank vault: it has cameras at the entrance, a steel door, a combination lock, a guard inside, and an alarm system. Cybersecurity works the same way, using multiple layers of defence.

Network security monitors the flow of data through communication channels and blocks unauthorised users.
Data security safeguards information from corruption, theft, or unauthorised access.
Endpoint security focuses on individual devices — laptops, smartphones, and tablets — which are often compromised through human behaviour. “Many people still underestimate how skillfully and strategically cybercriminals operate. Rather than exploiting technical vulnerabilities, they prey on human emotions,” explains Dr. Muriel Frank, a researcher who investigates how online scams evolve.

Cloud security protects data, applications, and services stored on remote servers from breaches or disruptions.
Critical infrastructure security protects the digital systems that power essential services, such as power grids and transportation networks. To advance research in this area, Prof. Vincent Lenders launched SnT’s Systems and Network Security (SNS) research group in 2025, supported by a €3.5 million FNR PEARL Chair.

Cyberdefence: the cyber arm of defence

Cyberdefence is cybersecurity applied to the defence domain. Where cybersecurity protects systems broadly, cyberdefence focuses specifically on protecting a nation’s essential information systems. In Luxembourg, the National Cyberdefence Strategy was published by its Department of Defence — demonstrating how seriously states now treat digital threats.

Through the Cyber Research Hub, SnT supports the government’s strategy through innovation and education. For example, a team is developing AI-enabled drone swarms to counter complex aerial threats.

4. Why does Cybersecurity matter?

By 2031, cybercrime is projected to cost $12.2 trillion every year. But the impact goes far beyond financial losses.

Healthcare: a matter of life and data

Patient records, imaging equipment, lab results, and medication dispensers all rely on digital networks. A security breach can paralyse modern hospitals within minutes.

In 2021, Ireland’s Health Service Executive (HSE) fell victim to a ransomware attack that encrypted 80% of its data, disrupting care across more than 4,000 locations and affecting 70,000 devices.

Finance: when stolen data becomes profit

Cybercriminals target banks relentlessly. The 2017 Equifax breach compromised the personal details of 147 million people, leading to widespread identity theft and fraud.

Critical infrastructure: built for safety, not security

Attacks on critical infrastructure are rising globally at more than 20% per year.

Businesses: the financial fallout

Cyberattacks don’t just hurt companies — they also harm the people who trust them. The 2013 Target breach compromised data belonging to 70 million customers. The company’s profits fell nearly 50% the following quarter.

Small businesses face particular risks: 60% shut down within six months of a major incident.

Government: data as a geopolitical weapon

Government agencies hold sensitive information, from tax records to national security secrets.

Election systems also face growing threats. SnT researchers are tackling this challenge with the EquiVox project, developing secure e-voting systems.

5. Where it stands: four key trends

As cyber threats evolve, four major trends are shaping this fast-moving race.

AI: the double-edged sword

AI can now scan vast amounts of data to spot unusual behaviour and respond to threats in seconds. But attackers use the same technology to craft convincing phishing emails, harder-to-detect malware, and deepfakes.

Fighting AI with AI, SnT researchers developed an algorithm to detect deepfakes in collaboration with Post Luxembourg.

The quantum threat

Today’s encryption relies on mathematical problems that would take classical computers thousands of years to solve. But one day, quantum computers could crack them in minutes.

Researchers are already preparing for that future. In 2024, SnT established the first Quantum Key Distribution (QKD) connection between Luxembourg and Belgium. QKD uses the laws of quantum mechanics to create encryption keys that are virtually impossible to break.

The skills gap

Cybersecurity is not only a technical challenge; it is also a human one. Worldwide, 3.5 million positions in this field remain unfilled.

To help close that gap, the University of Luxembourg launched a Master in Cybersecurity and Cyber Defence in 2024, combining the expertise of SnT and the Faculty of Science, Technology and Medicine. The Erasmus Mundus CYBERUS Master also contributes to training the next generation of cyber professionals.

The regulatory maze

Governments are responding to rising threats with stronger rules. In Europe, the General Data Protection Regulation (GDPR) and the NIS2 (Network and Information Security) Directive have raised the bar for data protection and cyber-resilience.

Yet regulations also create challenges. Companies must navigate a growing web of requirements, while innovation often outpaces the rules designed to govern them. Adding to the complexity, cybersecurity rarely fits within a single discipline. Technical systems, human behaviour, and legal frameworks all interact — but don’t speak the same language. A dedicated research group brings together engineers, lawyers, and social scientists to tackle exactly this. Their REMEDIS project develops regulatory frameworks and socio-technical solutions to counter online disinformation.

6. What’s next: cross-field innovation

To win the digital cat-and-mouse game, cybersecurity cannot be siloed. It cuts across computer science, IT, engineering, data analysis, social science, robotics, and more.

At SnT, nine research groups work with industry and government partners across a broad front — from deepfake detection and quantum-proof communication to critical infrastructure security and legal frameworks. That wide scope is exactly why the centre has made cybersecurity one of its four strategic research areas.

The momentum is building. Launched in 2023 to strengthen Luxembourg’s cyber defence capabilities, the Cyber Research Hub has now 12 projects underway. The Luxembourg Ministry of Defence has increased its initial financial contribution with an additional €2 million for 2026. Supporting the Cyber Research Hub, Prof. Lenders has been building the SNS research group from the ground up, engaging with key Luxembourg stakeholders and recruiting new talent.

Meanwhile, Prof. Gabriele Lenzini obtained a $500,000 Google grant focused on cybersecurity training and outreach. He has also been elected Chair of the European Cybersecurity Organization (ECSO), a working group on skills & Human factors aiming to bridge the cybersecurity skills gap.

What started as a playful message on ARPANET in 1971 now carries far higher stakes. In a field where speed and adaptation matter, the challenge is simple to state but difficult to achieve: stay one step ahead. SnT is meeting it head-on.