Back to DashboardExecutivePhase 3 · Risk Scoringbeginner30 min

PQC Risk Management

Identify, quantify, and prioritize quantum computing risks to your organization’s cryptographic infrastructure.

Why this matters: A CRQC timeline estimate is inherently uncertain — risk registers and heatmaps built from real threat data let an organization set migration priority without waiting for a certainty that will never come.

Start here: Write one HNDL risk in the Risk Register Builder — asset, likelihood, impact, owner — then carry it into the heatmap in step 3 to assign its treatment.

For your role

Executive / Business Leader: Model when a cryptographically relevant quantum computer could arrive, build the risk register, assign treatments and read the residual risk: priority without waiting for a certainty that will never come.
GRC / Risk & Compliance: The register with likelihood and impact, the treatment step with residual risk, and the Compliance Gap Analysis against CNSA 2.0 and NIST IR 8547 deadlines are the risk artefacts an audit expects.
Researcher / Academic: The CRQC timeline scenarios are parameterised and the register is built from real threat data on this site; the heatmap method is explicit.
Curious Explorer: Nobody knows when a quantum computer will break today's encryption; the module shows how to decide what to fix first anyway, with a simple risk table.

Practice in the Simulation

Quantum computers exploit quantum mechanical properties to solve certain mathematical problems exponentially faster than classical computers. Most critically, Shor's algorithm — running on a sufficiently powerful quantum computer — can factor large integers and solve discrete logarithm problems in polynomial time, which would break RSA, Diffie-Hellman, and elliptic curve cryptography that protect virtually all internet communications today.

Why PQC Risk Management?

The arrival of a will break the asymmetric cryptography that protects virtually all digital communications. Risk management provides the framework for understanding when this threat becomes real, what assets are exposed, and how to prioritize migration efforts.

“This means that even if quantum computers are a decade away, organizations must begin the migration to post-quantum cryptography today to avoid having their encrypted data exposed once quantum computers become operational in the future.”

— NIST IR 8547 ipd (Initial Public Draft), Transition to Post-Quantum Cryptography Standards, November 2024. Draft status: not final guidance.

Identify

Discover every cryptographic asset in your organization and map quantum vulnerability exposure.

Quantify

Assign likelihood and impact scores to each risk, calculate composite risk levels, and estimate exposure windows.

Prioritize

Rank risks by severity, align with compliance deadlines, and allocate migration resources where they matter most.

Key Concepts

PQC risk management introduces several concepts specific to quantum-era threats. Understanding these is essential for building an effective risk register.

CRQC Timeline

A Cryptographically Relevant Quantum Computer is one powerful enough to break RSA, ECC, and Diffie-Hellman key exchange. Quantum computers already exist; none published to date is cryptographically relevant, and the gap between the two is large. Published expert estimates for CRQC arrival vary widely — commonly spanning the 2030s and beyond — and they are opinion surveys, not measurements, so treat any single date as a planning assumption you choose rather than a forecast. Plan against the date you would regret being wrong about.

HNDL — Harvest Now, Decrypt Later

HNDL attacks involve adversaries capturing encrypted data today with the intent to decrypt it once quantum computers become available. Data with long confidentiality requirements (healthcare records, classified information, financial data) is already at risk even though quantum computers don't yet exist.

Risk Quantification

Quantum risk is quantified as Likelihood x Impact on a 1–5 scale for each dimension, producing a risk score from 1 to 25. Likelihood considers the probability that the asset's algorithm will be broken within its required protection lifetime. Impact considers the business, regulatory, and reputational consequences of a breach.

Weight by Quantum Vulnerability, Not Classical Strength

A common scoring mistake is to rank likelihood by an algorithm's classical strength. Against a CRQC that ranking inverts. Under Shor's algorithm, what matters is the public-key size and math family relative to the quantum resources needed to break it — not how many years a classical attacker would need.

ECC-256 is as urgent as RSA-2048. Classically, a 256-bit elliptic curve looks far stronger than a 2048-bit RSA modulus. But Shor solves the elliptic-curve discrete-log problem with fewer logical qubits than it needs to factor RSA-2048 — so a CRQC reaches ECC-256 at least as early. Both belong in the same top-urgency band.

Algorithm	Looks-strong (classical)	Quantum-vulnerability weight
RSA-2048	Standard baseline	Critical — Shor-breakable; HNDL clock running
ECC-256 (P-256)	Appears far stronger than RSA-2048	Critical — broken with fewer qubits than RSA-2048
RSA-4096 / ECC-384	Stronger still	Critical — bigger keys buy little against Shor
AES-256 (symmetric)	Strong	Low — only Grover (halved strength → 128-bit); no Shor break

Scoring rule: weight likelihood by Shor-breakability and key size, not classical key-strength. Asymmetric public-key algorithms (RSA, ECC, DH) share the same critical band; symmetric ciphers and hashes are only weakened (Grover), so doubling key length restores their margin. Source: Applied Quantum PQC Migration Framework §3 (Risk Scoring).

The Risk Management Process

This workshop walks you through a structured three-step quantum risk management process:

Step 1: CRQC Scenario Planning

Model when a quantum computer could arrive and see which algorithms, compliance deadlines, and data are at risk.

Step 2: Risk Register Building

Document every quantum-vulnerable cryptographic asset with likelihood, impact, and mitigation strategies.

Step 3: Risk Heatmap Visualization

Plot your risks on a 5x5 likelihood-impact grid to identify critical migration priorities.

Executive Perspective

For CISOs and security leaders, quantum risk management is not a future concern — it's a present-day requirement. Regulatory bodies worldwide are setting migration deadlines, and the HNDL threat means sensitive data is already at risk.

Regulatory Pressure

• NSA CNSA 2.0: PQC required for NSS by 2030–2035
• NIST IR 8547 ipd (draft): classical signatures at the 112-bit security level deprecated after 2030, disallowed after 2035 — a security-strength scope, not a blanket RSA/ECC ban
• EU/ANSSI: Active PQC transition guidance
• Financial regulators examining quantum risk

Business Impact