Quantum Computing and What It Means for Encryption

Article Written by: Rishi Ramachandran

Article Designed by: Rishi Ramachandran and Natasha Gumpula

You may have heard the phrase quantum computing tossed around and wondered what it actually means, and more importantly, why people in cybersecurity care so much about it all of a sudden. The short answer is that quantum computing has the potential to change how computers solve problems, and in doing so, it could break the encryption systems that protect almost everything we do online today.

This article will break down what quantum computing is, how it differs from classical computing, how modern encryption works, and why researchers are racing to prepare for a future where current security methods may no longer be enough.

Classical vs. Quantum Computing

Traditional computers are incredibly fast, but they all work in roughly the same way. They process information using bits, which are like tiny light switches. Each switch is either off, represented by a 0, or on, represented by a 1.

Every calculation your laptop makes ultimately boils down to long strings of these zeros and ones.

Quantum computers work very differently. Instead of bits, they use qubits. A qubit can be a 0, a 1, or both at the same time thanks to a property called superposition. One way to think about this is to imagine a librarian who can check every possible shelf at once instead of walking down one aisle at a time. Image from Fraunhofer

How Today’s Encryption Works

Encryption is what keeps our digital lives private. It scrambles readable data into unreadable code using mathematical algorithms and secret keys. Only someone with the correct key can turn that scrambled data back into something meaningful.

Some of the most common encryption systems in use today include:

• AES (Advanced Encryption Standard) A symmetric encryption method used to protect data both in transit and at rest. It comes in key sizes of 128, 192, and 256 bits.

• RSA (Rivest-Shamir-Adleman) An asymmetric encryption algorithm that relies on the difficulty of factoring very large prime numbers.

• ECC (Elliptic Curve Cryptography) Another asymmetric method that offers similar security to RSA but with smaller keys.

TLS (Transport Layer Security)

A protocol that combines several encryption methods to secure internet communications, such as when you visit a website over HTTPS.

These systems are considered secure because classical computers would take an unrealistically long time to break them. Cracking AES could take billions of years. Breaking RSA or ECC could take thousands of years. For decades, this time gap which prevents brute force attacks has kept our data safe.

What Is Quantum Cryptography?

Quantum cryptography takes a completely different approach to security. Instead of relying on hard math problems, it relies on the laws of physics.

One key idea is that observing quantum information changes it. For example, quantum key distribution uses photons whose properties shift when they are measured. If

someone tries to eavesdrop on a quantum-encrypted message, their interference can be detected instantly. This makes quantum cryptography especially appealing because it does not just make hacking difficult, it makes it obvious. 

The Quantum Threat: Why Encryption Could Break Overnight

Quantum computing changes this timeline dramatically. With the right algorithms, especially Shor’s algorithm, a powerful quantum computer could factor large numbers far more efficiently than a classical computer.

This means RSA and ECC could potentially be broken in hours or even minutes,

depending on the machine.

AES is still more resistant to quantum attacks, but even it becomes weaker in a quantum world. A quantum computer could reduce the effective security of AES keys, meaning stronger key    sizes would be needed to maintain safety.

Image from NIST

Why Quantum Cryptography Matters for the Future

Even though fully mature, large-scale quantum computers may still be 20 to 50 years away, the concern is not just about the future. Data stolen today can be stored and decrypted later once quantum technology improves. This is often called “harvest now, decrypt later.”

Quantum computing is not just another upgrade in speed. It represents a fundamental shift in how problems are solved. As that shift continues, the way we think about security will need to change with it.

Works Cited

“Quantum Computing – How it Changes Encryption as We Know It.” Security, Privacy, Audit, Risk, and Compliance Services (SPARCS), Division of Information Technology, University of Maryland, 18 Oct. 2024, it.umd.edu/security-privacy-audit-risk-and-compliance-services-sparcs/topic-week/quantum-computing-how-it-changes-encryption-we-know-it. Accessed 24 Jan. 2026. 

National Institute of Standards and Technology. What Is Post-Quantum Cryptography? NIST, 11 June 2025, https://www.nist.gov/cybersecurity/what-post-quantum-cryptography. Accessed 24 Jan. 2026.

Fraunhofer Institute for Industrial Mathematics ITWM. Quantum Computing Training Overview. Fraunhofer ITWM, https://www.itwm.fraunhofer.de/en/fields-of-application/quantum-computing/quantencomputingschulungen_ueberblick-en.html. Accessed 24 Jan. 2026.