Technologies

This section briefly introduces the range of different technologies that make use of specific quantum phenomena in new ways, what they could do, and how they might be used in future. We focus on those use cases that may involve processing personal information or have privacy and information rights implications. Our list excludes many other plausible and near-term use cases.

Timelines are not predictions, but are intended to reflect plausible futures.

1. Quantum sensing, timing and imaging

Many quantum sensing, timing and imaging technologies are best described as an evolution of existing technologies, offering new or significantly improved capabilities. Potential use cases range across academic research, medical diagnostics, autonomous vehicles, navigation, military and law enforcement surveillance.

Quantum sensors

Quantum sensors make use of specific quantum phenomena to detect and measure tiny physical changes, such as in magnetic fields, gravity and temperature. The ‘next generation’ of quantum sensors are significantly more accurate and more precise than existing sensors, either offering new sensing capabilities or enhancing existing capabilities ⁷. In future, they could be smaller, lighter and more cost effective than current sensors, if hardware improves and technical challenges are addressed ⁸. There are examples of investment and pilots across sectors such as the military, healthcare, neuroscience research, civil engineering and environmental monitoring.

There are many different categories of quantum sensor, such as quantum magnetic sensors and quantum gravity sensors. There are also different types of sensor within these broad categories.

• Quantum magnetic sensors could be used in various industries, from medical research to defence. For example, some types of sensor can be used for non-invasive, portable and more detailed medical diagnostic tools. This includes wearable brain scanning for epilepsy and Alzheimer’s, or diagnosing strokes in a GP surgery. These sensors are able to detect tiny changes in magnetic fields, such as changes generated by individual neurons firing in the brain or by muscle movement ⁹.
• Quantum gravity sensors could be used to detect and map underground infrastructure and hazards (such as pipes or cables) to much greater depths and more precisely than existing gravity sensors can. They could also be used for underwater mapping and navigation. One class of these sensors uses falling clouds of cold atoms to detect tiny changes in the Earth’s gravitational field caused by objects or, hypothetically, the presence of people. If successfully miniaturised, they could be used on a moving vehicle, or even a drone, unlike current versions.
  

Quantum timing technologies

Optical clocks are the next generation of ultra precise quantum timing technologies. The time measurements provided by existing quantum clocks (known as atomic clocks) are used for a range of purposes. For example, coordinating high speed online communications or determining location for navigation systems like GPS. Integrating even more precise and compact versions into navigation systems could be used:

• as a faster, more accurate alternative to GPS that is more resilient to jamming by malicious actors. The system could also function better in situations when GPS signal is affected by the environment (such as on a train in a tunnel, or underwater); or
• to enable advanced radar systems to:
  • identify stealth objects or small objects, such as drones, at greater distances; or
  • provide real time location insights and understanding of congested environments ¹⁰.
    

Quantum enhanced imaging

Cameras using novel quantum imaging technologies could offer significantly better resolution (detail) and contrast than existing imaging techniques, along with new capabilities ¹¹.

Depending on the type of imaging technique, use cases could include:

• defence and covert surveillance;
• search and rescue or law enforcement cargo scanning to combat human trafficking;
• improving how autonomous vehicles detect and respond to objects in real time; and
• improving non-invasive medical diagnostics and screening for conditions such as cancer.

Researchers have developed ways to give a visible image even in very low light environments, using only a single particle of light. This gives clear images for example, in fog, smoke or underwater. Some techniques can be used to take a picture in infrared using a normal camera, which has applications for biomedical imaging. Others can be used to detect objects and the presence of people around corners, behind walls, or through some opaque surfaces. They use an extremely fast camera to detect scattered particles of light. The next step for many of these techniques is to continue piloting and further refining them for real world applications. Others are far more experimental, such as ‘quantum ghost imaging’ (a technique for taking a picture even when light has not interacted with the object).

Broadly, many quantum sensing, timing and imaging technologies are at a more advanced stage of technical development than other quantum technologies. Some are already in the early stage of commercialisation. Despite significant UK investment for pilots in sectors such as defence, healthcare and infrastructure, there are still some barriers to further adoption, such as:

• commercial competition from existing technologies that are already highly effective and widely used. Novel use cases will need to demonstrate that they are fulfilling a specific unmet need ¹²;
• ongoing technical efforts to reduce size and cost; and
• supply chain challenges.

This means that the future market for many potential use cases most relevant to our remit is still highly uncertain.

Timelines for development of use cases

Current-five years	Increasing academic and military research. Some initial commercial prototypes
	Prototypes of many sensors and imaging techniques, with some early real-world deployments. Ongoing work to reduce their size and introduce commercialised versions. We could see the following: Early real-world deployments of magnetic quantum sensors and quantum imaging techniques in the medical research sector to support mental health therapies and diagnosis of cognitive and other health conditions. Ongoing experimentation for underground surveillance, voice detection at a distance, and detecting the presence of people using high resolution ghost imaging in the defence and national security sectors.
Five-10 years	Timescale and potential market for use cases outside healthcare and military highly uncertain over next five-10 years
	In the medical sector, the UK is aiming for every NHS trust to have access to quantum sensing systems for early diagnosis by 2030. Stakeholders suggest this may be difficult to achieve, but we could see magnetic quantum sensors for brain imaging or advanced quantum imaging technologies deployed in some hospitals for more accurate and portable diagnostics of conditions, such as epilepsy or heart conditions. Advances in defence applications of quantum sensing and imaging could start to extend into wider civil applications. For example, we may see real world pilots of surveillance devices integrating quantum sensors for high risk law enforcement, search and rescue or hostage recovery applications. For example, handheld sensors to detect concealed weapons at range that ignore other items, or larger imaging systems for detecting the presence of people after a flood or building collapse. Increased integration of optical clocks into existing global navigation satellite systems (GNSS) and GPS (ie the systems that enable real time location). At the far end of the timescale, quantum imaging technologies integrated into autonomous vehicles to improve how they identify and respond to obstacles.
10-15 years	Timescales and potential markets still highly uncertain. If pilots and initial applications are commercially and practically successful, we could see wider uses of quantum sensing and imaging techniques in addition to or instead of classical technologies
	We could see the following: Tests of quantum sensing, timing and imaging technologies in smart buildings and smart city infrastructure. For example: measuring energy consumption; coordinating information transfers between devices (timing); monitoring real time traffic; or detecting temperature density in populated areas such as shopping malls (to measure shopping habits). Quantum imaging capabilities may be integrated into new types of CCTV or drones. Certain quantum sensing and imaging techniques used in some GP surgeries or ambulances for portable diagnosis of fractures or heart conditions.
15-25 years	Potential wider integration (eg in healthcare and surveillance)
	We could see the following: Small, portable and reliable advanced magnetic quantum sensors integrated into various high-end consumer applications and wearable prescription devices. This includes health tech wearables that offer more precise measures of cardiac health, muscle responsiveness and neurological health. Wider adoption of certain quantum sensors in applications, such as brain-computer interfaces, when combined with advances in our understanding of the human brain. Optical clocks used to coordinate networks of commercial drones.

2. Quantum computing

In theory, a fully functional quantum computer could solve certain problems exponentially faster than the computers we use today. This includes some problems that are so difficult and time-consuming for classical computers to solve that they are considered ‘unsolvable’.

They are most likely to only be used for specific computational problems because they:

• are built very differently; and
• solve problems in a different way.

Organisations that do use quantum computing services are more likely to use them alongside existing computers, rather than to replace them. They are expensive and technically complex, so organisations are also more likely to use quantum computing services through the cloud. At least at this stage, the cost of accessing quantum resources is one of the barriers to wide-scale use ¹³.

As discussed in further detail later in this report, quantum computing also has well-documented impacts on certain types of encryption and future information security ¹⁴. We are interested in the ongoing efforts to address the risks to personal information that quantum computing may present.

Quantum computers make use of particle behaviour at an atomic or subatomic level to run computations. Classical computers (the computers we use today) process information represented as sequences of 1s and 0s (called digital ‘bits’). In contrast, quantum computers use quantum bits called ‘qubits’. Qubits can represent two states at the same time. This means they can be in both a position of 0 and 1, or importantly, somewhere in between. Qubits can be linked in a way that enables them to represent even more states at the same time. The phenomena responsible for this are known as superposition and entanglement. Due to these properties, the processing power of a quantum computer grows at an exponential rate for each extra qubit.

As noted in our most recent Tech horizons report, researchers are still working out which real-world problems may be best solved using a quantum computer. Many potential use cases are still theoretical, including many that could involve processing personal information. There are also significant barriers to overcome before we reach a fully functional quantum computer, also known as a “universally fault tolerant quantum computer”. It is even possible that we may never reach “quantum advantage” for some use cases (eg if classical machine learning overtakes quantum advances).

Many early anticipated use cases are unlikely to involve processing personal information. For example, using a quantum computer to solve a materials science or physics research problem. Therefore, they would not fall within the scope of data protection legislation. However, researchers and industry are exploring potential future use cases that include the following:

• Factorising very large numbers, which has implications for long term information security. Factorising underlies many existing encryption algorithms that protect digital information and communications.
• Modelling highly complex systems and simulating new chemicals, which offers possibilities for advances in areas like drug discovery and development and personalised medicine.
• Solving hard optimisation problems (ie problems that involve identifying the best option from multiple combinations). For example, in order to optimise workforce scheduling.
• Accelerating machine learning or improving data analysis for applications such as:
  
  • genomics;
  • biometrics;
  • natural language processing;
  • analysing and predicting customer behaviour for product targeting;
  • improving fraud detection in real time transaction information; and
  • classifying images, such as medical scans for diagnostics.
• Increasing search speed within complex datasets, or speeding up the systems used to recommend products and content on online shopping or media platforms.

Depending on what the computer is being used to calculate, the quantum computer may be processing personal information. Or, the outcome of its calculation may be applied to classical personal information and used to generate insights.

Researchers are also exploring different ways that quantum technologies could be used as, or combined with, classical privacy enhancing technologies (PETs) in future. There is research into:

• hybrid quantum computing to improve the computational efficiency of certain PETs ¹⁵;
• federated quantum machine learning, which would allow a group of organisations to process sensitive information (such as special category data) individually using a quantum computer, and share insights (but not the raw information) with a combined classical model to improve it; and
• blind quantum computing, which offers a person or organisation accessing a quantum computer from the cloud, a different way to completely hide the problem they are solving, the calculation, and answer from the quantum computing server (and the organisation that provides the quantum computing service).

Timelines for development of use cases

Current-five years	Noisy intermediate-scale quantum computers (smaller scale prototype computers) and experimentation phase 16. Prototype versions of quantum computers are already available via the cloud for research purposes and industry testing. Partnerships with companies and quantum computers available for public to access remotely for very short periods of time
	We could continue to see the following: Research and pilots of hybrid quantum-classical applications that use existing quantum computing resources to identify potential improvements on classical AI, and machine learning approaches that will deliver value for commercial applications. More pilot projects focusing on hybrid quantum-classical applications in sectors such as financial services, retail healthcare, and life sciences. For example, certain organisations may experiment with using a quantum computer via the cloud as part of a process to: optimise workforce timetables or digital marketing; allocate energy resources to households; personalise financial products; and optimise customer financial portfolios, or customer profiling that takes into account a wider range of factors than is currently possible. Other experiments include: computer vision (which involves searching through large volumes of images to recognise pictures, such as medical images); and exploring whether quantum natural language processing, a type of machine learning, could one day help machines understand and use language in a way that is more consistent with how humans use language, for advanced future chatbots and virtual assistants. Ongoing exploration of whether adding quantum capabilities to a classical datacentre could improve the efficiency of the datacentre to help it process ever growing volumes of information.
Five-10 years	Mid-scale quantum computers (1000 or more qubits) may begin to demonstrate quantum advantage for certain real world applications (eg improving machine learning)
	If UK capabilities improve and experimentation and pilots increase in the public and private sector, we are also likely to see new applications emerge. For example, in the financial sector, relevant use cases could include using advances in quantum machine learning to improve credit scoring or fraud detection. Five-10 years is the earliest projected timeframe for a cryptographically relevant quantum computer to emerge, but predictions are highly varied (five-30 years or more).
10-15 years	By 2035, the UK is aiming for a sufficiently advanced quantum computer capable of demonstrating high impact in sectors such as healthcare and finance
	For example, in the healthcare sector, this could include adopting hybrid approaches to accelerate analysis of genomic data, or accelerating diagnostics from medical images. Depending on the development of quantum computing hardware and software, blind quantum computing could become viable for business-to-business use. It could also be possible that we see early devices for people to use to set up a ‘secure’ channel to a quantum computer. In tandem, we could see a push for access controls on quantum computers over this period. Post-quantum cryptography: The United States (US) has recommended that all critical public systems are upgraded by 2035. The European Union (EU) has recommended member states outline a roadmap to ensure transition "as swiftly as possible". The UK has not set a date for expected transition.
15-25 years or more	Universal fault tolerant computers (computers sufficiently powerful and reliable for a wide range of real world applications)
	We could see developments that include the following: Computers sufficiently powerful for a wide range of real-world applications, and wider integration of quantum computers into an organisation's computing systems. Many of the potential use cases are yet to be imagined. Some estimates suggest such computers could arrive within 10-20 years. Currently highly speculative uses of interest to us include: polygenic risk scoring 17; biometric data analysis; using federated quantum machine learning as a privacy enhancing technique; personalised diagnostics; modelling neural activity in a digital twin of the brain; real time credit scoring; and analysing customer behaviour from financial transactions and social media behaviour. PETs built for quantum computation may also become viable during this time, such as: federated quantum machine learning; quantum differential privacy; and quantum-enhanced secure multi-party computation. We may see the emergence of quantum databases that allow information (eg video, images, music or text) to be stored, organised and queried while still in a quantum state.

3. Quantum communications

There are ongoing UK testbeds and trials of quantum communication networks as an additional way to address the risks to encryption posed by a future quantum computer. Proponents argue that quantum communications will complement the security provided by other techniques, such as post-quantum cryptography ¹⁸.

Quantum communications refers to ways of transmitting information securely using quantum mechanics ¹⁹. The main technique is known as quantum key distribution (QKD), a way of securely sharing encryption keys. QKD uses the physical properties of light in a quantum state, rather than using maths problems for security (as in classical encryption). Essentially, sharing the key is secured using the laws of nature ²⁰.

Some suggest that in future QKD could be used together with post-quantum cryptography. This would help protect highly sensitive information transfers against a future quantum computer capable of solving the mathematical problems used in certain types of encryption ²¹. It could secure a range of devices, systems and personal information processing, from securing mobile two-factor authentication for online banking to smart buildings and wider digital communications ²². However, QKD is not currently endorsed by the NCSC for future post-quantum security.

Some stakeholders suggest that QKD is already technically viable. For example, the Quantum Communications Hub have operated a testbed UK quantum network for many years. BT and Toshiba are trialling a commercial QKD network in London. Some other countries are also experimenting with, or have rolled out, QKD networks.

Despite this progress, there are several hurdles in the UK to overcome for further development, such as:

• the cost of implementing QKD networks;
• levels of government and industry demand; and
• appetite to invest.

Hardware and engineering limitations also mean that quantum information can currently be transmitted across and between UK cities (up to 100km), but not internationally ²³.

Beyond QKD, in the medium term, researchers also hope to link together smaller quantum computers in different places into a more powerful quantum computer. This also opens up the much longer-term possibility of a future national and international network of quantum computers, referred to as a “quantum internet”. This would run alongside the classical internet to securely send and receive information in a quantum state (eg qubits), which current networks cannot do. The quantum internet could also be used to send information still in its quantum state from a quantum sensor network (such as in a smart city) to a quantum computer for analysis ²⁴.

Research into linking quantum computers together is still in the early stages of development. As a first step towards a quantum internet, researchers are currently exploring other ways to securely transmit information in a quantum state rather than as classical information ²⁵. The Quantum Communications Hub is also exploring ways to link quantum computers together. Furthermore, in 2024, UK researchers linked several networks together in a single quantum state for the first time ²⁶.

Timelines for development of use cases

Current-five years
	BT and Toshiba already have a commercial quantum key distribution (QKD) trial ongoing in London. Wider uptake will depend on factors such as government and industry appetite to invest in the hardware and network implementation. We may also see additional pilots of quantum key distribution (QKD) for high-risk commercial applications, such as telecommunications networks, finance and healthcare. In such cases, QKD could be increasingly offered as an ‘extra’ for an additional fee.
Five-10 years
	If QKD takes off, we may see progressive bolt ons of QKD, a wider QKD network and increasing use of QKD, (eg for government systems). We may see satellite-based QKD between countries that cannot be supported by fibre. We may also see reliable assurance mechanisms in place that help provide confidence to organisations implementing QKD.
10-15 years
	We could see early QKD for consumer devices (eg smartphones). The UK aims to link quantum computers together at a small scale by 2035. Depending on the development of quantum computers, we may see initial commercial pilots of networked quantum computers by the end of this period. Developments here may also support improvements in QKD, making security easier to certify. We may see some overseas examples of drones used as part of civilian QKD networks. Countries such as the US and China are already experimenting with military applications, but to date the UK has focused on using satellites and existing fibre optic telecoms networks.
15-25 years or more
	Depending on the development of quantum computers, we may see a wider national and international network of quantum computers and blind quantum computing using secure quantum channels to share information. At the far end of the timeline we may see emergence of the quantum internet.

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⁷ UK Quantum Sensing and Timing Hub webpage on quantum sensing: big to small technology; Regulatory Horizons Council Independent report on regulating quantum technology applications (2024)

⁸ For example, interference from the external environment in real world use cases currently impacts on the accuracy of the measurements.

⁹ See, eg, Cerca Magnetics website introducing their brain imaging system based on optically-pumped magnetometers (known as an OPM-MEG System); Quantum Sensing and Timing Hub webpage on sensing the brain

¹⁰ UK Quantum sensing and timing hub webpage on pinpointing the exact location

¹¹ Cureus article on the quantum-medical nexus: Understanding the impact of quantum technologies on healthcare (2023)

¹² IEEEAccess research article on Exploring quantum sensing potential for systems applications (2023)

¹³ techUK report on Quantum commercialisation: Positioning the UK for success (2022) . In the short term, accessing them is likely to involve at least some access to overseas quantum computing capacity, as the UK continues to scale its domestic infrastructure.

¹⁴ Specifically, it could be used to solve the mathematical problems that are used in some common types of encryption. See, eg NCSC whitepaper on preparing for quantum-safe cryptography (2020)

¹⁵ Such as fully homomorphic encryption.

¹⁶ These machines are mid-scale working quantum computers with 50-100 or more qubits. They are prone to errors. They are a step on the road to a fully functional quantum computer that exceeds the performance of super computers and can be used for experimentation and demonstrating some early capabilities. See, eg, DRCF quantum technologies paper and Article by John Preskill on quantum computing in the NISQ era and beyond (2018)

¹⁷ Polygenic risk scores look at the potential impact of many genomic markers to estimate “an individual’s genetic risk for some trait” or disease. Nuffield Department of Population Health article from the Frontiers journal on calculating polygenic risk scores (PRS) in UK Biobank: A practical guide for epidemiologists (2022)

¹⁸ Post-quantum cryptography is a new type of classical encryption believed to be resistant to the known risks posed by a future quantum computer - that is, the ability to factorise large numbers and undermine some types of existing encryption.

¹⁹ Quantum Communications Hub webpage on the background to quantum communications technologies

²⁰ More specifically, the key is sent as a quantum light pulse, which changes when measured. So, any attempt to copy, intercept or eavesdrop when sending the encryption key would introduce detectable errors. Quantum Communications Hub article on quantum key distribution. QKD is however susceptible to what are known as implementation and side channel attacks: German Federal Office for Information Security article: A study of implementation attacks against QKD systems.

²¹ This is known as a cryptographically relevant quantum computer.

²² See eg, Quantum Communications Hub: What does QKD mean for the economy?; Quantum Communications Hub: Consumer QKD

²³ Efforts are ongoing to use satellites to allow communication over longer distances.

²⁴ University of Chicago News article on the quantum internet, explained; IET Quantum Communication article on the quantum internet: A synergy of quantum information technologies and 6G networks (2023)

²⁵ IET Quantum Communication article on the quantum internet: A synergy of quantum information technologies and 6G networks (2023); DRCF Quantum Technologies Insights Paper

²⁶ Imperial College London news release ‘Crucial connection for ‘quantum internet’ made for the first time’ (2024)