Page 228 - Cyber Defense eMagazine September 2025

like a light switch being either on or off. That binary certainty has been the bedrock of our security. But
on the horizon, there is a profound change, a disruptive, almost cosmic-level event in the form
of quantum computing.

Unlike classical bits, quantum bits or qubits can exist in multiple states simultaneously thanks to
principles known as superposition and entanglement (National Institute of Standards and Technology
[NIST], 2023). This fundamentally alters the rules of the cryptographic game. The sheer computational
power of quantum machines could soon dismantle encryption protocols that we once considered
unbreakable. This isn’t just an upgrade in processing speed, it’s a rewriting of the universe’s digital laws,
demanding new strategies for survival.

The Fundamentals of Quantum Computing

To understand the threat, we must first journey into the “subatomic” realm of computation, where the
boundaries of conventional logic blur, and probability takes the lead role.

Qubits are the basic units of quantum information. Unlike traditional bits, which can only store a 1 or a
0, qubits can store both at the same time—up until the moment they are measured. This is due
to superposition, a phenomenon that allows multiple potential realities to coexist.

Imagine trying to find your way out of a massive maze. A classical computer would try one path at a time
until it found the exit. A quantum computer, leveraging superposition, travels all paths at once and
determines the solution in a fraction of the time.

But the real magic happens when you introduce entanglement—a phenomenon Albert Einstein famously
called “spooky action at a distance.” Entangled qubits remain linked no matter how far apart they are,
such that a change in one instantly affects the other. In computing terms, this allows for incredibly
coordinated, parallel processing that vastly increases efficiency (Yuan et al., 2017).

The third key concept is quantum parallelism, which gives quantum computers their massive theoretical
advantage. Because of superposition, they can work on an astronomical number of possibilities
simultaneously, compressing centuries of classical computation into potentially seconds or minutes.

Some key concepts in short:

• Qubit: Infinitely more expressive than a bit, can be 0, 1, or both.
• Superposition: Multiple states exist in parallel until observed.
• Entanglement: Linked particles share the same state instantaneously.
• Quantum Parallelism: Multiple possibilities tested simultaneously.

Current research from industry leaders such as IBM, Google, and IonQ is pushing towards what is known
as quantum advantage—the tipping point where a quantum system can perform a calculation that is
impractical for even the largest classical supercomputer (NIST, 2023). Once fault-tolerant quantum
computing is achieved, formerly invincible encryption methods may fall rapidly.

Cyber Defense eMagazine – September 2025 Edition 228
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