Key Notes

  • Today's encryption relies on math that quantum computers could break.
  • A powerful enough quantum computer would threaten much online security.
  • "Harvest now, decrypt later" makes the threat urgent today.
  • Post-quantum cryptography uses new, quantum-resistant methods.
  • The transition is a massive, already-underway undertaking.

A Looming Threat to Digital Security

Almost everything we do online is protected by cryptography — the mathematics that keeps our messages private, our payments secure, and our identities verified. Much of this security rests on mathematical problems that are practically impossible for today's computers to solve, such as factoring enormous numbers. But a new kind of machine is on the horizon that could change everything. A sufficiently powerful quantum computer could solve some of these problems with alarming ease, potentially breaking much of the encryption that secures the modern world. Preparing for this — quantum-safe or post-quantum cryptography — has become one of the most important challenges in cybersecurity, and it is studied closely at AIRCST.

Why Quantum Computers Threaten Encryption

Today's most widely used encryption methods depend on certain mathematical problems being extraordinarily hard — so hard that even the fastest conventional computers would take effectively forever to solve them. This difficulty is what keeps encrypted data safe. Quantum computers, however, operate on entirely different principles, and for certain specific problems — including the ones underpinning much of today's encryption — a powerful quantum computer could be vastly faster, solving in a manageable time what would take conventional machines billions of years.

This does not mean quantum computers break all encryption, nor that the threat is here today — building a quantum computer powerful enough remains a formidable challenge still being worked on. But the trajectory is clear enough, and the consequences serious enough, that the world cannot afford to wait. The security that protects much of the digital world rests on math a future quantum computer could unravel.

The Urgency: Harvest Now, Decrypt Later

A crucial and sobering point makes this threat urgent today, even before powerful quantum computers exist. Adversaries can capture and store encrypted data now, intending to decrypt it later once quantum computers become capable — a strategy called harvest now, decrypt later. Any sensitive information that must remain secret for years into the future — government secrets, medical records, financial data, personal communications — could be vulnerable if captured today and decrypted tomorrow. For data that must stay secret for a long time, the quantum threat is effectively a present-day problem. This is why the transition to quantum-safe methods is being pursued with urgency rather than left for the distant future.

What Post-Quantum Cryptography Is

Post-quantum cryptography develops new encryption methods designed to resist attacks from both conventional and quantum computers. These methods are based on different, carefully chosen mathematical problems believed to be hard even for quantum machines. Importantly, post-quantum cryptography runs on ordinary computers — it does not require quantum technology itself; it simply uses math that quantum computers cannot easily break.

A major, coordinated effort has been underway to identify, rigorously test, and standardize these new algorithms, so that organizations can begin adopting them. Standardizing cryptography is painstaking work — the methods must be scrutinized intensely to ensure they are truly secure before the world relies on them.

A Concrete Example

Consider an organization that handles data which must remain confidential for decades — say, sensitive records that would cause harm if ever exposed. Even though no quantum computer can break today's encryption yet, an adversary could be quietly capturing this organization's encrypted data now, storing it to decrypt once quantum computers mature. If the organization waits until quantum computers arrive to upgrade its security, it is already too late — the data captured today will be exposed. A forward-thinking organization instead begins transitioning to quantum-safe cryptography now, so that the data it protects today remains secure even against the quantum computers of the future. The threat is distant, but the defense must begin in the present.

Why This Matters

The security of the entire digital world — commerce, communication, infrastructure, privacy — depends on cryptography. The prospect of quantum computers breaking that cryptography is one of the most significant long-term challenges facing cybersecurity. Transitioning the world's systems to quantum-safe methods is an enormous undertaking that must begin well before the threat fully materializes. The cybersecurity professionals who understand this transition and help carry it out are protecting the foundations of digital trust.

Looking Ahead

The migration to post-quantum cryptography is a massive, multi-year effort already underway, as standards emerge and organizations begin to adopt quantum-resistant methods. The goal is to secure the digital world against the quantum computers of the future before they arrive. It is a rare case of defending against a threat ahead of time — and getting it right is essential to the security of the decades to come.

Secure the Future — Research Cybersecurity at AIRCST

At the Aleta International Research Center for Science and Technology (AIRCST), our cybersecurity researchers study how to protect data against the threats of tomorrow, including the quantum era. If you want to help secure the digital future, explore our research programs and join us, or get in touch to learn more.