Introduction: Preparing for Quantum Threats
A French startup, Alice & Bob, estimates that RSA-2048 could be factored using Shor's algorithm with fewer than 23,000 physical qubits in just three days. While this estimate requires peer review and real-world scaling is unproven, it's clear that resource estimates are decreasing due to advancements in error correction.
For compliance managers, the key takeaway isn't predicting a "Q-Day" but recognizing that data protected today might need to remain confidential longer than current algorithms can ensure. "Harvest now, decrypt later" means attackers could steal encrypted data now and decrypt it when quantum capabilities improve. This is critical for long-lived data like medical records or intellectual property.
This checklist provides ten actionable items linked to ISO/IEC 27001:2022 and SOC 2 criteria. While not explicitly mandated by these frameworks, they align with existing obligations.
Prerequisites
Before starting, ensure you have:
- A current risk register and approved risk assessment methodology (ISO/IEC 27001 clause 6.1.2)
- Access to your asset inventory and data classification scheme
- A designated cryptography owner (such as a security architect)
- Authority to update your Risk Treatment Plan
Checklist Items
1. Inventory Public-Key Cryptography Use Catalog all uses of public-key cryptography, including TLS endpoints, VPNs, code signing, and more. Focus on RSA and elliptic-curve algorithms, which are vulnerable to Shor's algorithm. Reference: Annex A 5.9; SOC 2 CC6.1. Good looks like: A regularly updated inventory listing algorithm, key length, owner, system, and protected data.
2. Classify Data by Confidentiality Lifetime Add a "must remain confidential until" attribute to your data classification scheme. Different data types have varying confidentiality needs. Reference: Annex A 5.12; SOC 2 C1.1. Good looks like: Each data class has a confidentiality horizon, with long-lived classes flagged as quantum-exposed.
3. Identify Harvest-Now Exposure Cross-reference your cryptography inventory with data classification. Identify data flows that are long-lived and protected by vulnerable cryptography. Good looks like: A prioritized list of data flows where long confidentiality lifetime meets quantum-vulnerable protection.
4. Add Quantum to Your Risk Assessment Conduct a Scenario-Based Risk Assessment for the early arrival of a cryptographically relevant quantum computer. Use falling qubit estimates as evidence of changing likelihood. Reference: ISO/IEC 27001 clause 6.1.2 and 8.2; SOC 2 CC3.2. Good looks like: A documented scenario with likelihood reasoning and impact analysis.
5. Update the Risk Treatment Decision Decide on a treatment for each quantum-exposed flow: migrate, compensate, accept, or retire the data. Record decisions in your Risk Treatment Plan. Reference: clause 6.1.3; Statement of Applicability. Good looks like: No exposed flow is untreated, and any acceptance is documented with management approval.
6. Set a Cryptographic Policy Position Revise your cryptographic policy to address post-quantum algorithms, crypto-agility, and standards for new systems. Reference: Annex A 8.24; clause 7.5. Good looks like: An approved, versioned policy that new projects must follow, with exceptions logged.
7. Require Crypto-Agility in New Builds Ensure algorithm selection is configurable, allowing for easy updates. Integrate this into your Secure Development Lifecycle. Reference: Annex A 8.25 and 8.26; SOC 2 CC8.1. Good looks like: Design reviews confirm algorithms are abstracted, and architecture standards reflect this.
8. Query Suppliers and Subservice Providers Ask vendors about their post-quantum roadmap and data protection methods. Include this in supplier due diligence. Reference: Annex A 5.19 to 5.22; ISO/IEC 27036; SOC 2 CC9.2. Good looks like: Documented responses from critical suppliers, with gaps tracked as risks.
9. Plan the Pilot and Track Standards Select a low-risk system for a post-quantum key exchange pilot. Follow NIST and regulatory algorithm standards, and verify FIPS-Validated Cryptography requirements. Good looks like: A scoped pilot with success criteria and a person monitoring standards bodies.
10. Brief Leadership and Record It Present your exposure and treatment plan to top management, and document the decision in management review minutes. Reference: clause 9.3; Performance Evaluation under clause 9. Good looks like: Minutes showing leadership received the risk, approved resources, and set a review date.
Common Mistakes
- Waiting for a Deadline: No framework sets a quantum deadline, but your risk assessment obligation remains.
- Inventorying Only Your Own Code: Vulnerable cryptography may exist in vendor products and forgotten certificates.
- Treating All Data Equally: Without considering confidentiality lifetime, you risk misallocating resources.
- Overreacting to a Single Estimate: Use trends to plan, not panic.
- Skipping Evidence: Document all decisions for assessor credit.
Next Steps
Start with items 1 through 3 this quarter; they're cost-effective and foundational. Update your Risk Treatment Plan for top exposures, and integrate findings into your next management review and Statement of Applicability. When auditors inquire about emerging threats, you'll have a traceable process from inventory to decision.
