Pre-standardisation Algorithms (Beta)

Pre-standardisation Algorithms (Beta Support)

ExeQuantum supports select pre-standardisation post-quantum algorithms for early access and hybrid cryptographic use cases. These algorithms are considered beta, and are made available to help organisations explore and test post-quantum resilience ahead of formal NIST standardisation.

By offering early access to algorithms such as HQC, ExeQuantum enables integrators, developers, and researchers to validate compatibility, assess performance, and prepare infrastructure for broader post-quantum transitions — without waiting for the final standards to be published. These implementations are hardened and fully functional, but may be subject to future updates as specifications evolve.

Beta Support: HQC (Hamming Quasi-Cyclic)

We currently offer production-hardened support for the HQC algorithm, a code-based Key Encapsulation Mechanism (KEM) finalist from the NIST PQC process. While HQC is not part of the initial 2024 NIST standardisation set, it has been selected to be standardised in 2027 as a backup algorithm to ML-KEM, in response to concerns about the long-term security assumptions of lattice-based cryptography.

HQC is based on the hardness of decoding random linear codes, a completely different mathematical foundation from ML-KEM (lattices) or ECC (elliptic curves), making it a valuable component in hybrid schemes.

⚠Advisory

ExeQuantum recommends using HQC in hybrid mode with a standardised KEM (e.g. ML-KEM / Kyber) and optionally ECC (e.g. X25519 or P-256) until NIST finalises the HQC standard.

This hybrid approach ensures cryptographic agility and resilience in the face of unforeseen cryptanalytic developments.

HQC Beta Endpoints

These endpoints behave exactly like their ML-KEM counterparts, but are namespaced under /api/hqc to reflect their beta status. Based on advice and guidelines, HQC may be integrated into the main kem endpoints either in addition to ML-KEM or in its stead.

Operation	Endpoint
Key Generation	/api/hqc/generate_keys
Encapsulation	/api/hqc/encapsulate_key
Decapsulation	/api/hqc/decapsulate_key

All response formats, shared secrets, and ciphertexts use the same format as standardised PQC endpoints.

No additional parsing or transformation is required when integrating HQC beta endpoints into an existing cryptographic flow.

Hybrid Usage

Applications may use the HQC shared secret in conjunction with ML-KEM and/or ECC-derived secrets. This is typically done by combining secrets via KDFs such as HKDF or HMAC, e.g.:

hybrid_secret = HKDF(mlkem_ss || hqc_ss || ecc_ss)

ExeQuantum supports hybrid constructs at the application layer, or can offer pre-constructed hybrid schemes upon request. Reach out to our team to discuss custom hybrid integrations.

What's Next: Classic McEliece

ExeQuantum is actively investigating support for Classic McEliece, another code-based KEM algorithm selected for long-term standardisation. Once internal testing and hardening are complete, we expect to release Classic McEliece endpoints under a similar /api/mceliece namespace with equivalent usage patterns and hybrid support.

Stay tuned for updates on timelines, availability, and implementation status.

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For further guidance or integration support, contact ExeQuantum at [e-mail].