The development of quantum computers does not mean that all encryption used on the internet has suddenly become ineffective. Current systems do not yet have the cryptographic capacity to break strong RSA and elliptic-curve keys at a practical scale. However, it would also be unwise to postpone preparations for data that must remain confidential for years. Attackers can copy encrypted data today and try to decrypt it in the future once a sufficiently powerful computer becomes available. This risk, known as “harvest now, decrypt later,” is especially important for health, legal, government, research, and trade-secret archives.
In 2024, NIST published the first three finalized post-quantum cryptography standards: ML-KEM for key establishment, and ML-DSA and SLH-DSA for digital signatures. In 2025, the agency selected the HQC algorithm as a backup encryption approach to ML-KEM. These developments do not mean that users should buy any product marketed as “quantum-protected.” They show that software and service providers can transition on the basis of open standards.
First determine which data needs protection
Start preparing by classifying data lifetimes, not by purchasing an algorithm. A session cookie, a current shopping list, childhood photographs, and a patient record do not need to remain confidential for the same length of time. Divide data into groups that suit your needs, such as “less than one year,” “several years,” and “ten years or longer.” Record how many copies of long-lived, sensitive information exist on devices, in the cloud, in email, on old drives, and in backups.
Safely reducing unnecessary copies provides a concrete benefit even against an unknown future technology. However, do not delete the only backup. First test whether another intact, restorable copy of the file exists. If the password for an encrypted archive, its recovery key, or the software used to create it is unknown, the data may be lost entirely during migration to a newer algorithm.
What should home users do?
Keep your phone, computer, browser, password manager, router, and backup tool up to date. Leaving an unsupported device exposed to the internet while preparing for the quantum threat would mean ignoring today’s security vulnerabilities. When buying a new device, compare the update period promised by the manufacturer, its security advisories, and the support it provides for older models.
Continue using unique passwords, passkeys, multi-factor authentication, and offline recovery codes. Post-quantum cryptography does not prevent phishing, malicious applications, weak screen locks, or the deceptive extraction of a one-time code. Do not discard your current security key simply because its packaging does not say “quantum.” Ask the manufacturer which protocol it uses and about its update roadmap.
If you are creating a long-term encrypted archive, choose a widely used, current tool that is open to independent review. Document the file format, software version, key owner, and most recent restoration test. Perform at least one sample restoration each year. If your service provider announces post-quantum protection, find out whether it applies to stored files, only to the network connection, or only to newly generated keys.
How can a “quantum-resistant” claim be assessed?
Ask which standard and algorithm the product uses. Descriptions such as “military-grade,” “quantum-safe,” or “future-ready” alone are not verifiable technical explanations. The exact name of the NIST standard, the protocol in which it is implemented, an independent security review, and the method used in the event of failure should be specified.
Some services offer hybrid key exchange that combines classical and post-quantum algorithms. This approach can be useful during the transition, but the word “hybrid” is not proof of security by itself. Examine whether the connection silently falls back to a weaker method when it encounters an older client, where keys are generated, and in which version of the application the feature is enabled.
Do not develop your own encryption algorithm or make an experimental implementation the sole layer of protection for a valuable archive. Even if the name of the standardized algorithm is correct, a faulty implementation, weak random-number generation, or key leakage can compromise the entire system.
A migration inventory for small businesses
List the public-key cryptography used in web certificates, VPNs, email security, code signing, identity management, API connections, payment systems, and backups. For each entry, record the algorithm, software library, certificate lifetime, data confidentiality lifetime, vendor, and responsible person. NIST’s current migration work also identifies cryptographic visibility and inventory as foundational stages.
Ask vendors three specific questions: In which product version will they support the NIST standards, can the transition be completed through a software update alone, and how will compatibility with older clients be managed? Instead of accepting “We have a plan,” request a date, version, and test documentation.
Test new algorithms first in an environment where changes can be rolled back. Measure how key and signature sizes affect gateways, smart cards, embedded devices, and databases. Test the certificate chain, signature verification, and disaster recovery processes together. The goal is not to replace every system overnight, but to create an auditable roadmap that begins with the most long-lived and sensitive data.
Research sources
- NIST, post-quantum cryptography overview: https://www.nist.gov/pqc
- NIST NCCoE, Migration to Post-Quantum Cryptography project: https://www.nccoe.nist.gov/applied-cryptography/migration-to-pqc
- NIST NCCoE, current migration questions and answers: https://pages.nist.gov/nccoe-migration-post-quantum-cryptography/