Lab 06 · Standards & selection · 30–40 minutes
NIST PQC: Same Goal, Different Jobs
Discover what ML-KEM, ML-DSA, and SLH-DSA share, where they differ, and why the task comes before the algorithm.
Finalized FIPS 203, 204, and 205 · No account needed
PQC is a toolbox, not one replacement algorithm
NIST publishes standards that specify how cryptographic algorithms work. This lab compares three finalized standards: ML-KEM (FIPS 203), ML-DSA (FIPS 204), and SLH-DSA (FIPS 205). They share a goal of resisting known classical and quantum attacks, but they do not all do the same job.
Agree on a secret
ML-KEM lets two parties establish a shared secret. A symmetric cipher such as AES can then protect their data. This is not a signature and does not, by itself, prove who the other party is.
Verify a message
ML-DSA and SLH-DSA sign messages. A recipient checks the signature with a trusted public key to detect changes and verify the signer. A signature does not hide the message.
Two ways to build signatures
ML-KEM and ML-DSA are module-lattice-based: their security relies on hard problems in structured mathematical objects called lattices. SLH-DSA is stateless hash-based: it builds signatures from cryptographic hash functions without requiring a running record of one-time keys already used.
You do not need to calculate a lattice to compare their roles. Think “same job, different construction,” not “one must be better at everything.”
Selected is not the same as finalized
The NIST sources checked for this lab identify Falcon / FN-DSA and HQC as selected for ongoing standardization, not finalized FIPS covered here. Selection, a draft, and final publication are different stages. Other NIST publications also cover quantum-resistant cryptography; this is a focused comparison of FIPS 203–205.
Check NIST's current project status ↗All three run on ordinary computers. A standardized algorithm is not proof that a whole product is validated, compliant, or secure.