Quantum-Safe Encryption: Are We Ready?

Quantum computing has been the subject of breathless headlines for years, often portrayed as either the dawn of a technological utopia or an unstoppable cyber apocalypse. In reality, the truth sits somewhere between those extremes. We don’t have a cryptographically relevant quantum computer (CRQC) yet, that is, a quantum machine powerful enough to break the encryption protecting the world’s digital communications. But progress in quantum hardware and algorithms is steady, and the world’s largest governments, cloud providers, and chipmakers are no longer asking “if” such a machine will exist. They’re asking “when” and, more importantly, “how will we be ready when it does?”

The answer is not as simple as swapping in a new cipher. Our encryption systems are woven deeply into how organizations authenticate users, protect data in motion, sign code, secure firmware, and manage digital identities. Preparing for quantum-safe encryption means untangling that web and methodically replacing the threads before they unravel on their own.

This article explains the quantum threat to today’s encryption, what’s changing in standards, and most importantly, what CIOs and CISOs can do now to get ahead of the shift.

Why Quantum Computing Changes the Game

The internet’s security foundation today is built on mathematical problems that are easy to set up but very hard to solve. RSA relies on factoring large integers. Diffie-Hellman and elliptic-curve cryptography (ECC) rely on the difficulty of computing discrete logarithms. On classical computers, these problems are so computationally expensive that with large enough key sizes, they’re practically unbreakable.

Quantum computers, however, exploit the strange properties of quantum mechanics, superposition, and entanglement, to process information in fundamentally new ways. In 1994, mathematician Peter Shor discovered an algorithm that could factor large integers and compute discrete logarithms exponentially faster than classical methods. In practical terms, a sufficiently powerful quantum computer running Shor’s algorithm could break RSA, Diffie-Hellman, and ECDSA/ECDH in a matter of hours or days.

That would mean the handshake that secures your VPN, the certificate that validates your website, and the signature that verifies your software updates could all be forged or decrypted.

The danger is not limited to the moment CRQCs arrive. There is a very real “harvest-now, decrypt-later” threat. Adversaries can capture and store encrypted traffic today—sensitive emails, intellectual property, classified documents—with the intent of decrypting it years later when quantum machines mature. This makes quantum risk a present-day concern for any data that must remain confidential for years or decades.

Symmetric vs. Asymmetric: A Critical Distinction

Not all encryption is equally vulnerable. Shor’s algorithm devastates asymmetric systems like RSA and ECC. Symmetric algorithms, such as AES, are far more resistant. The best-known quantum attack against them, Grover’s algorithm, offers only a quadratic speedup. That means an AES-256 key would have the equivalent security of AES-128 in a post-quantum world, which is still considered robust.

The practical takeaway: you don’t need to abandon AES or SHA entirely, but you should favor larger key sizes (AES-256 over AES-128, SHA-384 or SHA-512 over SHA-256) for long-term safety.

The Standards Have Arrived

For years, the U.S. National Institute of Standards and Technology (NIST) has been running an open competition to select post-quantum cryptographic algorithms. That process is now bearing fruit. In 2024, NIST finalized the first three quantum-safe standards:

• FIPS 203 – ML-KEM: A key encapsulation mechanism based on lattice cryptography, standardized from the CRYSTALS-Kyber algorithm. This is intended to replace RSA and ECC for key exchange in protocols like TLS and VPNs.

• FIPS 204 – ML-DSA: A digital signature algorithm standardized from CRYSTALS-Dilithium. This will replace ECDSA and RSA signatures in applications like code signing, PKI certificates, and authentication tokens.

• FIPS 205 – SLH-DSA: A stateless hash-based signature algorithm standardized from SPHINCS+. It is larger and slower than lattice-based options but offers mathematical diversity in case lattice-based cryptography ever encounters unforeseen weaknesses.

This isn’t just an academic milestone. These algorithms are the building blocks that vendors will be implementing across browsers, operating systems, hardware security modules, TLS libraries, VPN appliances, and IoT devices over the coming years.

The Government Timelines That Will Drive the Market

Even if your organization does not handle classified government data, it’s worth paying attention to the NSA’s Commercial National Security Algorithm Suite 2.0 (CNSA 2.0). It sets explicit dates for migrating National Security Systems to post-quantum cryptography:

• By January 1, 2027: All new acquisitions must be capable of CNSA 2.0 algorithms.

• By December 31, 2030: Classical-only cryptography must be phased out in these systems.

• By December 31, 2031: CNSA 2.0 algorithms must be fully deployed.

Because many major vendors sell into both government and commercial markets, these deadlines will heavily influence the pace at which products become quantum-safe.

What This Means for Your Technology Stack

The shift to quantum-safe encryption will be more complex than past key-length upgrades. Here’s why:

• Bigger keys and messages: Post-quantum public keys, signatures, and handshake messages are significantly larger than their classical counterparts. This can affect performance, bandwidth, and compatibility with existing network infrastructure.

• Crypto agility is mandatory: Applications and devices must be able to swap cryptographic algorithms without redesigning the entire system. Hard-coded crypto will become a liability.

• Hybrid deployments: For years, we’ll see hybrid protocols that combine a classical algorithm (like ECDHE) with a post-quantum algorithm (like ML-KEM) so that connections remain secure even if one is broken. This ensures backward compatibility while adding quantum resistance.

A CIO’s 12-Month Action Plan

1. First 60 Days – Get Visibility

• Appoint a program owner for post-quantum migration, someone with authority to coordinate across IT, security, procurement, and development.

• Build a cryptographic inventory. Document where and how RSA, ECC, and other algorithms are used across your organization, TLS endpoints, VPNs, email encryption, document signing, firmware signing, databases, and backups.

• Classify data by confidentiality lifetime. Identify which information would remain sensitive five, ten, or twenty years from now.

2. Days 60–120 – Define Your Strategy

• Set policy baselines: prefer AES-256 for symmetric encryption, SHA-384 or SHA-512 for hashing, and plan to adopt ML-KEM and ML-DSA for public-key needs.

• Require crypto agility in all new procurements, whether it’s a cloud service, a SaaS app, or a network appliance.

• Update contracts with vendors to include quantum-safe timelines and compliance clauses.

3. Days 120–180 – Test the Future

• Pilot hybrid TLS with ML-KEM in a controlled environment, perhaps on an internal portal or partner API.

• Stand up a test PKI that issues ML-DSA or SLH-DSA certificates and verify that your systems can enroll, validate, and revoke them.

• Experiment with post-quantum code signing on a low-risk project to understand build, signing, and verification impacts.

4. Days 180–270 – Expand and Integrate

• Upgrade cryptographic libraries, HSMs, and middleware to versions that support the new NIST standards.

• Work with vendors to confirm post-quantum roadmaps for all mission-critical products: VPNs, firewalls, load balancers, mobile device management, endpoint protection, IoT/OT gear.

• Re-encrypt high-value archives with AES-256 and post-quantum-protected key wrapping.

5. Days 270–365 – Operationalize

• Deploy dual-stack environments where both classical and post-quantum algorithms are supported, falling back only when necessary.

• Update incident response procedures for handling post-quantum key compromise.

• Brief the board on your readiness status, with metrics, timelines, and risk areas.

Patterns That Make Migration Easier

• TLS 1.3 everywhere: It’s more flexible and already being extended to support hybrid post-quantum key exchanges.

• Gateway-first upgrades: Updating load balancers, VPN concentrators, and email gateways first can shield legacy systems during the transition.

• Crypto-agile PKI: Ensure your certificate authorities can issue both classical and quantum-safe certificates, potentially in cross-signed chains.

• Modular signing pipelines: Design your build systems so you can change signing algorithms without breaking verification downstream.

Common Pitfalls to Avoid

• Waiting for “full vendor support” before taking any action. There’s plenty you can do right now: inventory, policy setting, vendor engagement, and pilots.

• Ignoring performance and compatibility testing. Larger handshake messages can cause unexpected failures in middleboxes, firewalls, or IoT devices.

• Treating migration as a one-time project. Post-quantum adoption will be a multi-year, phased program with multiple stages of hybrid deployment.

What “Ready” Looks Like

Readiness doesn’t mean every endpoint in your organization is running quantum-safe encryption tomorrow. It means:

1. You know exactly where your vulnerable cryptography is.

2. Your policies and procurement standards favor quantum-safe algorithms.

3. You can run post-quantum protocols in production for at least your most critical services.

4. Your vendors are contractually committed to a migration path.

If you can say “yes” to those four points, you’ve dramatically reduced your exposure to the harvest-now, decrypt-later threat and positioned your organization to adapt smoothly as standards evolve.

The Bottom Line

The technology to break RSA and ECC isn’t here yet, but the time to prepare is now. The first wave of post-quantum standards is finalized. The government has set clear adoption timelines. Major vendors are moving to integrate quantum-safe options into their products.

By acting early, before you’re forced to, you avoid rushed deployments, budget shocks, and vendor lock-in. You also send a clear message to customers, partners, and regulators: your organization treats long-term data security as a strategic priority.

At Bylinear, we help enterprises navigate this change with cryptographic inventories, readiness workshops, pilot deployments, and vendor program management. The shift to quantum-safe encryption is inevitable. Whether it’s disruptive or routine is entirely up to the preparation you do today