Quantum computing is transitioning from theoretical physics to practical engineering, and its implications for cybersecurity, drug discovery, and optimisation are profound. Here's what every technology professional should understand.

What Makes Quantum Computers Different?

Classical computers use bits — 0 or 1. Quantum computers use qubits, which can exist in a superposition of both 0 and 1 simultaneously thanks to quantum mechanical principles. Two additional properties — entanglement and interference — allow quantum computers to explore exponentially many solutions simultaneously.

The Encryption Threat: Shor's Algorithm

In 1994, mathematician Peter Shor proved that a sufficiently powerful quantum computer could factor large integers exponentially faster than any classical algorithm. This breaks RSA encryption, which underpins most of the internet's security infrastructure. With 4,000+ logical qubits, a quantum computer could crack 2048-bit RSA keys in hours rather than millions of years.

Current State: NISQ Era

We are currently in the Noisy Intermediate-Scale Quantum (NISQ) era — IBM's quantum computers have 100–1,000 physical qubits, but error rates are still significant. Experts estimate fault-tolerant quantum computers capable of running Shor's algorithm at scale are 10–20 years away.

Post-Quantum Cryptography

NIST finalised its first post-quantum cryptography standards in 2024. CRYSTALS-Kyber (key encapsulation) and CRYSTALS-Dilithium (digital signatures) are the recommended replacements. Start migrating now.

Getting Started with Qiskit

IBM's open-source Qiskit framework lets you write and run quantum circuits in Python on real quantum hardware for free. Our Quantum Computing Bootcamp teaches Qiskit hands-on.