Foundations
Which cryptography is affected?
What you will understand
Separate public-key migration from symmetric encryption and hash-function decisions.
Last reviewed:
Understand the context
RSA, finite-field Diffie–Hellman, and elliptic-curve public-key schemes rely on mathematical problems that would be vulnerable to a sufficiently capable quantum computer using Shor’s algorithm. Their uses include key establishment and signatures. A repository reference alone does not establish that the scheme protects a reachable production path.
Plan the work
Symmetric encryption and hash functions have different quantum considerations. Generic quantum search can affect security margins, but it does not mean every symmetric cipher or hash is broken in the same way as RSA. Review parameter sizes and the role of each primitive against applicable guidance; do not replace a password hash with a PQC signature algorithm.
Evidence to review
Inventory the purpose, algorithm, parameters, provider, key management, and protocol around each use. Separate encryption, authentication, signing, hashing, key derivation, and random-number generation. Include dependencies hidden behind TLS libraries, identity providers, software signing, and managed storage. Confirm runtime settings where evidence is available.
Limits and next steps
An algorithm-by-algorithm spreadsheet is only a starting point. A secure primitive can be deployed incorrectly, and a migration can introduce unrelated failures. Assess the whole construction and use established provider-supported implementations. FIPS 203, 204, and 205 define particular public-key mechanisms rather than universal replacements for every cryptographic function.
Evidence and limitations
Educational guidance with referenced standards; no customer system has been assessed for this article. Implementation and protocol support must be verified for the selected environment.