FAQ

Quick answers to questions we hear often. Open a Discussion if yours isn’t here.

General

What is Confium?

Confium is an open-source framework for multi-stakeholder threshold cryptography. It bundles 6 products: Threshold (signing), Transparency (audit logs), PKI (cert authorities), Keyless (OIDC-based signing), Privacy (PSI/MPC/DP), Verify (multi-language verification).

Why “Confium”?

Latin for “trust”. The framework is about distributing trust across multiple parties so no single party is a single point of failure.

Who owns Confium?

The Confium project, stewarded by Ribose. BSD-2-Clause licensed; no CLA; no commercial edition. Sponsored by NLnet and Mozilla MOSS — see FUNDING.yml.

Is there a hosted / SaaS version?

No. Confium is self-hosted only by design. The trust model requires that the operator of the threshold quorum is the consumer; a hosted threshold service re-introduces a single point of trust. See GOVERNANCE.md for the rationale.

Threshold

What’s the difference between CMP20, GG18, FROST?

GG18 (2018): 4-round threshold ECDSA. First practical protocol.
CMP20 (2020): 3-round threshold ECDSA. Faster, simpler. Preferred for new deployments.
FROST (2020): 2-round threshold Schnorr/EdDSA. Different signature scheme (Schnorr vs ECDSA).

See the Threshold product docs for the full matrix.

Can I use Confium with my existing HSM?

Yes — via PKCS#11 v3.0. See the PKCS#11 server spec. Supported HSMs: YubiHSM, Nitrokey HSM, Thales Luna, Utimaco, AWS CloudHSM, Azure Managed HSM, Google Cloud HSM.

What’s the minimum T-of-N?

T=2 (2-of-N). Below that you have a single-party signing scheme, which defeats the point.

What’s the maximum T-of-N?

Practical limit is ~50 parties for CMP20 / GG18 (network round overhead). FROST scales further (~100+).

Transparency

Is Confium’s transparency log the same as Certificate Transparency?

Conceptually yes — both implement RFC 6962. Operationally no — CT is operated by Google / Apple / Cloudflare as a public good; Confium’s logs can be operated by anyone for any purpose (cert issuance, supply chain provenance, regulatory audit trails).

What happens if the log operator goes rogue?

The log can silently rewrite history only if witnesses don’t notice. Confium mitigates via witness gossip: independent witnesses sign observed tree heads, so any fork becomes publicly detectable. For high-assurance use, anchor tree heads to Bitcoin via OTS every hour — see ots-bitcoin-anchoring.mdx.

PKI

Can Confium replace my existing CA?

Yes, if you control the root. Confium becomes the threshold signing layer behind your root key — see Threshold CA spec. End-user certificates verify in any standard X.509 chain validator (OpenSSL, BoringSSL, system trust stores).

What about post-quantum?

Composite signatures ship today (Ed25519 + ECDSA-P256). ML-DSA-65 / SLH-DSA composites land in v0.4 once the FIPS 204 crates are released. See Composite signatures spec.

Will Confium work with OpenSSL / Java / Go?

OpenSSL 3.0: Yes, via the Confium provider. See confium-openssl-provider.
Java (JCE): Yes, via the Confium JCE provider. See confium-jce-provider.
Go: Yes, via standard crypto/x509 — Confium-issued certs are vanilla X.509.

Keyless

What’s “keyless”?

Signing without the signer ever holding a long-lived key. Confium issues a short-lived (10 min) certificate to an ephemeral public key, anchored to an OIDC identity (GitHub Actions, Google, GitLab, etc.). The signer signs with the ephemeral key; the cert is published to a transparency log; the ephemeral private key is destroyed.

What if Confium’s keyless CA goes down?

Existing keyless signatures remain verifiable — the cert + signature + transparency log entry is all self-contained. New keyless signing stops until the CA recovers. For high-availability, run your own keyless CA via the threshold CA guide.

Does keyless signing work offline?

No. OIDC JWT verification requires network access to the provider’s JWKS, and the short-lived cert issuance requires network access to the Confium keyless endpoint. Once signed, verification works offline.

Privacy

Is Confium’s PSI production-ready?

For 2-party, semi-honest security, yes — up to ~10M element sets. For malicious security or N-party, use the confium-privacy crate APIs directly.

How is this different from FHE?

Confium’s privacy surface uses specific primitives (PSI, PIR, DP, MPC) that are dramatically faster than general FHE. FHE (confium-tc-fhe-bfv) is research-grade and out of scope for v1.0 — the long-term plan is tracked in the repository root.

Verify

Can I verify Confium signatures without installing anything?

Yes — @confium/confium-wasm runs in any browser. See verify-in-browser.mdx.

What languages are supported?

Rust, Python, Ruby, Node.js, WASM/TypeScript, Go. See the bindings parity matrix for feature coverage.

Operations

How do I monitor a production Confium deployment?

Prometheus exporter in confium-signerd and confium-log-server. Pre-built Grafana dashboard at deploy/grafana/confium-coordinator.json. See prometheus-monitoring.mdx.

How do I back up shares?

Each share lives under HSM protection in production. The share file (when stored on disk) should be encrypted with the operator’s KMS. Rotate via Herzberg refresh — see refresh-shares.mdx.

How do I upgrade without downtime?

confium-signerd supports graceful shutdown (in-flight sessions complete; new sessions rejected). Rolling-update the replicas one at a time. See deploy-signerd-k8s.mdx.

Licensing & contribution

License?

BSD-2-Clause. No CLA. No commercial edition. Forever.

Can I use Confium in a closed-source commercial product?

Yes. BSD-2-Clause permits this. Attribution requirements are minimal (preserve the copyright notice).

How do I contribute?

See CONTRIBUTING.md. Small PRs welcome any time; large architectural changes should start as a Discussion or spec PR.

Still have questions? GitHub Discussions is the right place.

FAQ