Post-quantum VPN
ML-KEM-1024, NIST Category 5 and FIPS 203: What They Mean
Quick answer
ML-KEM-1024 is the FIPS 203 parameter set associated with NIST security category 5. In ALightVPN it is the post-quantum component of SecP384r1MLKEM1024. The category describes that component's security target; it does not certify the entire VPN service, its implementation or its certificate authentication.
What a category describes
People often search for a “NIST level 5 VPN.” The precise term here is security category 5 for the ML-KEM-1024 component. NIST's categories provide reference attack-cost targets; they are not an overall product score.
The target is benchmarked against exhaustive key search on AES-256. This does not mean ML-KEM encrypts traffic with AES, nor does it assign the same strength to certificate signatures, software handling secrets, or endpoints. Review those components on their own terms.
Standardization, validation and audits
| Claim | Evidence to look for | What it does not establish |
|---|---|---|
| Uses an algorithm standardized in FIPS 203 | Parameter set and implementation documentation. | FIPS 140 validation of the deployed module. |
| Uses SecP384r1MLKEM1024 | Release policy and selected-group diagnostics. | Post-quantum signatures on every certificate. |
| Uses a validated cryptographic module | Matching validation record, module version, operating environment and approved mode. | Certification of every surrounding service feature. |
| Independently audited | An identified report with date, scope and findings. | Assurance beyond the report's scope or review period. |
This page explains the standards used in the product's key agreement. It makes no claim of service certification, module validation or an independent ALightVPN audit.
ML-KEM and the Kyber name
ML-KEM developed from the Kyber submission to NIST's standardization process. Older names may appear in articles or experimental software. A historical name alone does not establish compatibility with a finalized ML-KEM implementation or the TLS hybrid group used by the current release.
For deployment decisions, use the exact group name, library version and supported package. Consult NIST's publication page for the standard and current errata rather than treating a marketing abbreviation as a specification.
Evaluate the connection as a whole
Check authentication, key establishment, data-channel encryption and the protection of credentials at rest. A category label cannot replace updates, correct certificate validation or protection of a compromised device.
Use the implementation guide to understand the boundary and the verification guide to identify evidence for an actual session. For procurement, request evidence for the particular requirement rather than assuming an algorithm label answers every compliance question.
Common questions
Is ALightVPN automatically FIPS-certified because it uses ML-KEM?
No. Standardizing an algorithm is different from validating a cryptographic module or certifying a service.
Does category 5 apply to the entire SecP384r1MLKEM1024 connection?
The category here describes the ML-KEM-1024 component. Other components and the complete deployment require separate assessment.
Is ML-KEM a certificate-signature algorithm?
No. It is a key-encapsulation mechanism used to establish shared secret material. Certificate signatures have a separate role.
Sources and product references
- NIST FIPS 203: ML-KEM standard and errata
- RFC 10024: hybrid key agreement for TLS 1.3
- NIST: preparing for post-quantum cryptography
- Official ALightVPN downloads
Reviewed 2 November 2026. Release configuration and platform availability are distinct from live-session test evidence.