What is Post-Quantum Cryptography (PQC)?

What is Post-Quantum Cryptography?

Post-Quantum Cryptography (PQC) refers to cryptographic methods designed to remain secure—even when quantum computers become capable of breaking today’s encryption. These algorithms don’t need quantum technology to run. They work on classical systems but are built to withstand quantum-level attacks.

Here's why PQC matters. Because the encryption that protects most digital systems today—like RSA (Rivest–Shamir–Adleman) and ECC (Elliptic Curve Cryptography)—won’t hold up in a quantum future.

Here's why PQC matters now

 Quantum computing isn’t hypothetical anymore. As capabilities grow, so does the risk to long-term data security. Nation-states and threat actors are already collecting encrypted data today, planning to decrypt it once the hardware catches up—a tactic known as “harvest now, decrypt later.”

PQC changes the equation. It gives organizations a way to:

• Protect sensitive data with longer shelf lives
• Meet upcoming compliance requirements (like U.S. federal mandates)
• Safeguard identity systems from future decryption risks

It’s not about whether quantum computing will become a threat. It’s about when—and whether you’re ready.

How PQC works

Post-Quantum Cryptography uses new mathematical approaches that resist both classical and quantum attacks.

These include:

• Lattice-based encryption: Built on structured math problems that are hard to solve, even with quantum speed.
• Hash-based signatures: Rely on one-way functions that remain quantum-resistant.
• Code-based and multivariate techniques: Add diversity and options for different use cases.

These aren’t theoretical. They’re already being tested, standardized, and implemented—on systems that need future-proof protection.

What’s changing in the industry?

Government agencies and cybersecurity leaders are moving early:

• NIST is finalizing PQC algorithm standards.
• CISA is advising organizations to begin crypto inventories.
• National Security Memorandum 10 mandates a federal roadmap for PQC migration.

If your systems handle long-term data or critical identity functions, waiting isn’t a strategy. Planning now reduces risk and simplifies future transitions.

Where to start with PQC

Most organizations begin with:

• A cryptographic inventory: What algorithms are in use, and where?
• Risk assessment: Which systems store data that needs to remain secure long-term?
• Pilot deployments: Testing hybrid or quantum-resistant protocols in parallel with existing ones.

Migration won’t happen overnight. But steps taken today determine how exposed you’ll be tomorrow.

Finally, Post-Quantum Cryptography isn’t an upgrade. It’s a shift. As encryption standards evolve, so must the systems and strategies that depend on them.

Related Resource: Quantum Computing: The Impact on AI and Cybersecurity