What if computers could one day solve problems that are beyond even today's supercomputers? That is the promise of quantum computing. For banks, the technology holds exciting new opportunities - but it also poses challenges, especially for the encryption methods widely used today.
Quantum computers are not simply faster versions of conventional computers. They work in a fundamentally different way and could eventually outperform even the most powerful supercomputers. For everyday tasks, however, conventional computers are generally faster and more practical, and today's quantum systems remain highly error prone. Quantum computing is instead expected to be useful in tackling particularly complex problems such as molecular simulations, logistics optimisation and certain applications involving artificial intelligence.
The technology is still being developed, but its potential is considerable. The latest Quantum Technology Monitor from McKinsey estimates that quantum computing could generate USD 1.3 to USD 2.7 trillion in economic value worldwide by 2035.
However, alongside the opportunities, companies must also assess the potential risks. "Quantum computing is going to fundamentally transform cyber security in the coming years," says Marco Brenner, Quantum Safe Programme Executive at IBM. LGT security expert Christian Pfister agrees, explaining that, "Quantum computers target precisely those mathematical problems that underpin almost all of today's key security mechanisms on the internet and in the financial sector."
Conventional computers process information using bits, the smallest units of digital data. Each bit has one of two values: zero or one. Inside the processor, billions of tiny transistors act like switches, with their off or on state representing these two values.
Quantum computers work differently. Instead of bits, they use quantum bits, or qubits. Under the laws of quantum mechanics, qubits can exist not only as zero or one, but also in a superposition of states - in other words, both at the same time.
Their states can also become entangled, meaning that the state of one particle is linked to that of another. Quantum computers use both phenomena, enabling them to process a huge number of calculations at the same time.
Cyber security mechanisms already protect systems against threats such as fraud, malware and attacks. Becoming "quantum safe", however, requires looking much further ahead.
Quantum computers could one day break widely used forms of public key cryptography, putting the information it protects at risk. And that threat is already relevant. Encrypted data can be stored by third parties today with the aim of decrypting it once quantum computers become available, an approach referred to as "harvest now, decrypt later". Data that needs to remain confidential for a long time is particularly at risk.
Being "quantum safe" means protecting data and systems against risks posed by future quantum computers. IT security experts are accustomed to constantly adapting their defences as technology evolves. But the potential impact of quantum computing is unusually broad.
As LGT security expert Christian Pfister explains, "It is not an entirely new type of risk, but it has taken on a new dimension in terms of depth and scope."
No one knows for certain when or if quantum computers will become available outside of laboratories and universities. But preparations for this eventuality must nonetheless to be made. "There may not be much certainty about the timing, but there is a lot of certainty about the need to start making careful preparations now," says Pfister.
LGT began collaborating with IBM Research in 2021, and according to Brenner, was "one of our first clients in this area". The aim was to support LGT's long-term transition to becoming quantum safe.
Over the years, both sides have benefited from the collaboration. "Our work with LGT has not only provided valuable insights for our research but has also helped us further develop our methods," says Brenner. "And as an early adopter, LGT has benefited from its direct exchange with IBM Research and from timely access to the latest findings and developments in quantum-safe cryptography."
The collaboration began with an analysis to determine where and how encryption was being used across LGT's complex IT environment, and which data and systems would require the greatest protection over the long term. Building on that analysis, LGT developed a target state for quantum-safe encryption and a roadmap for getting there.
The partnership with IBM has since been concluded, and LGT now has the capabilities and structures it needs to continue on its path to being quantum safe independently.
Existing IT systems are being upgraded in stages, and new standards are being introduced for algorithms, protocols, certificates and key management. In addition, new internal and external solutions are now subject to quantum-safe requirements.
An in-house centre of expertise for quantum cryptography is designing and managing these measures. The project is currently in the implementation phase and is expected to become part of regular operations in 2029.
Long term, the goal is not simply to make encryption more complex. LGT ultimately wants to become "crypto agile" - able to adapt digital communications, certificates and key management swiftly and in a controlled manner as risks evolve - with as little impact as possible on day-to-day operations.
In this way, LGT is strengthening its ability to protect its technological infrastructure in the future. At the same time, the measures being taken today are already strengthening LGT's resilience and benefiting its clients - regardless of when, exactly, cryptographically relevant quantum computers become available.
Between November 2025 and January 2026, the Swiss Financial Market Supervisory Authority (FINMA) surveyed 60 Swiss financial institutions about the opportunities and risks associated with quantum computing.
According to FINMA guidance issued in July 2026, financial institutions are monitoring the technology and are aware of the associated cyber risks. However, the regulator warned that the sector generally lacks a clear roadmap and sufficiently forward-looking plans for the migration to quantum-safe encryption.
The issue of quantum security is also being addressed in a number of other countries. In the US, the National Institute of Standards and Technology (NIST) has introduced standards in this area, while Germany’s Bundesamt für Sicherheit in der Informationstechnik (BSI) has issued related guidance and recommendations. The EU is also taking action.
