The next major cybersecurity threat may not come from conventional hackers or malware. It could come from computers that do not yet exist at scale.

Quantum computing is developing rapidly, and cybersecurity experts are increasingly preparing for a future in which powerful quantum machines could break some of the encryption methods currently used to protect digital information.

India's cybersecurity ecosystem is already beginning to respond. Recent developments include growing investment in quantum-safe security technologies, as businesses and governments prepare for the possibility that today's encryption could eventually become vulnerable. (business-standard.com)

What Is Quantum Computing?

Traditional computers process information using bits that represent either 0 or 1.

Quantum computers use quantum bits, or qubits, which can exploit quantum-mechanical properties to perform certain types of calculations in fundamentally different ways.

That does not mean quantum computers will replace ordinary laptops or smartphones.

Instead, they are being developed for specialised problems that could be extremely difficult for conventional computers to solve efficiently.

Potential applications include:

• Drug discovery

• Materials research

• Financial modelling

• Complex optimisation

• Scientific simulations

• Cryptography

But the same technology that could help solve difficult scientific problems could also create serious cybersecurity challenges.

Why Is Encryption at Risk?

Much of today's digital security relies on mathematical problems that are extremely difficult for conventional computers to solve.

For example, some widely used public-key encryption systems depend on the difficulty of factoring very large numbers or solving related mathematical problems.

A sufficiently powerful quantum computer running algorithms such as Shor's algorithm could potentially solve some of these problems much faster than a conventional computer.

That could threaten technologies used to secure websites, digital communications and other sensitive information.

Importantly, this does not mean today's encryption can suddenly be broken by existing quantum computers. Large-scale fault-tolerant quantum machines capable of posing such a threat are not currently available.

The “Harvest Now, Decrypt Later” Problem

There is another reason cybersecurity experts are preparing early.

An attacker could potentially steal encrypted information today and store it for years.

If sufficiently powerful quantum computers become available in the future, that stored information could potentially be decrypted.

This strategy is commonly referred to as “harvest now, decrypt later.”

It is particularly concerning for information that needs to remain confidential for many years, such as government records, financial information, intellectual property and sensitive corporate communications.

What Is Quantum-Safe Cryptography?

The solution is not necessarily to stop using encryption.

Instead, researchers are developing new algorithms designed to remain secure against both conventional and quantum computers.

These are generally referred to as post-quantum cryptography (PQC) or quantum-resistant cryptography.

The objective is to replace vulnerable cryptographic systems before powerful quantum computers become capable of attacking them.

The transition could take years because encryption is built into enormous numbers of systems around the world.

Why India Is Paying Attention

India has a rapidly expanding digital economy.

Online banking, UPI, government services, cloud computing, telecommunications and enterprise systems all depend on cryptography.

That makes long-term cybersecurity particularly important.

Recent Indian investment in quantum-safe security reflects growing demand from organisations that want to protect sensitive data against future quantum threats. Business Standard reported that Indian quantum-security company QNu Labs raised ₹200 crore to expand its technology and global operations amid increasing demand for quantum-safe cybersecurity infrastructure. (business-standard.com)

Will Your UPI or Banking Passwords Stop Working?

No.

There is no reason for ordinary users to suddenly change their banking passwords because of quantum computing.

The transition to post-quantum security is primarily an infrastructure and technology-industry issue.

Banks, cloud providers, governments, telecom operators and software companies will gradually need to assess which cryptographic systems they use and replace vulnerable technologies where necessary.

For consumers, much of this transition should happen behind the scenes.

Why the Transition Could Take Years

Modern digital systems often contain many layers of encryption.

Replacing one cryptographic algorithm may require changes to:

• Websites

• Mobile applications

• Operating systems

• Servers

• Banking infrastructure

• Digital certificates

• Network equipment

• Cloud platforms

• Embedded devices

Organisations also need to test new algorithms to make sure that replacing existing encryption does not create compatibility or performance problems.

That is why cybersecurity experts are encouraging organisations to begin preparing before quantum computers become a practical threat.

Quantum Security Is Not Only About Encryption

Quantum technologies could also introduce new methods of securing communications.

One example is Quantum Key Distribution (QKD), which uses quantum properties to establish cryptographic keys.

India has been developing capabilities in this area as part of its broader quantum-technology ambitions.

However, QKD is not a universal replacement for conventional encryption. It requires specialised infrastructure and has different technical and deployment requirements.

Post-quantum cryptography is therefore likely to play a major role in protecting ordinary internet infrastructure.

What Could Happen to Smartphones and Apps?

Most users will probably not notice the transition immediately.

As operating systems, browsers and apps adopt post-quantum cryptographic standards, devices could gradually begin supporting newer security protocols.

The process may look similar to other major security upgrades: software updates will introduce new capabilities while older systems are gradually phased out.

For users, keeping phones, computers and applications updated will remain one of the simplest ways to benefit from these improvements.

AI and Quantum Computing Could Change Cybersecurity Together

Quantum computing is developing at the same time as artificial intelligence.

AI is already being used by both cybersecurity professionals and attackers.

Future security systems could potentially combine AI-based threat detection with quantum-resistant cryptography.

At the same time, attackers could use AI to discover vulnerabilities, automate attacks and analyse stolen information.

This means cybersecurity in the coming decade is likely to involve multiple rapidly developing technologies rather than one single threat.

What Should Businesses Do?

Companies handling sensitive information should not wait until large-scale quantum computers arrive before assessing their systems.

A sensible starting point is to create a cryptographic inventory — a record of where and how encryption is being used.

Businesses can then identify systems that may require migration to post-quantum algorithms.

They should also check whether their cloud providers, software vendors and security partners have quantum-readiness plans.

The Biggest Takeaway

Quantum computing is still an emerging technology, but its potential cybersecurity impact is significant enough that preparation has already begun.

The objective is not to predict exactly when a machine capable of breaking today's strongest encryption will arrive.

Instead, organisations are preparing early because upgrading the world's digital security infrastructure could take many years.

For ordinary users, there is no need to panic. The most useful steps remain familiar ones: keep software updated, use strong unique passwords, enable two-factor authentication and be cautious about suspicious messages and links.

Behind the scenes, however, the cybersecurity industry is preparing for a much bigger change — a transition to encryption designed to remain secure even when powerful quantum computers eventually become reality.

Bottom Line

The quantum-computing revolution is still in its early stages, but cybersecurity experts are already preparing for its consequences.

Post-quantum cryptography could become one of the most important technology upgrades of the next decade, protecting banking, government, cloud services and communications against future quantum attacks.

The transition may not be visible to most consumers, but it could fundamentally change the security technology protecting the internet.