History that survives Q-day
Every checkpoint is signed with ML-DSA, the NIST post-quantum signature standard (FIPS 204). After today’s signatures can be broken, your certificates still separate the real chain from a forged one.
Product · PQC Sidecar
Protect your blockchain’s history from quantum forgery, starting today.
Once quantum computers can break today’s signatures, attackers can forge blocks your chain has already finalized. PQC Sidecar issues post-quantum proof of the real history as it happens, so bridges, custodians, and auditors hold evidence that still stands after Q-day.
No hard fork. No validator coordination. Just deploy one sidecar beside one node.
What you get
Trust now, forge later is the signature problem. This closes it for your history.
No fork, no coordination
Nothing changes on-chain: no validator upgrades, no governance vote, no protocol migration. One sidecar runs beside one node you already operate.
Evidence auditors can use
A standard algorithm, signing keys that can live in AWS KMS hardware security modules, and certificates you can hand to a quantum-readiness review today.
Verify anywhere, no lock-in
About 3.4 KB per checkpoint, checkable with any standard ML-DSA library. Rust and TypeScript verifiers are available, and the TypeScript one is open source (Apache 2.0); no custom cryptography is involved.
Who it’s for
Anyone who depends on a chain they can’t upgrade themselves.
- Bridges and interoperability
- A quantum-safe reference for the source-chain state you relay and prove.
- Custodians and exchanges
- Readiness evidence for the chains you hold but cannot upgrade yourself.
- Auditors, archives, compliance
- Long-lived records whose integrity outlasts today’s signature schemes.
- Chain foundations
- Cover your ecosystem’s history now, while a native migration takes years.
Why now
Secure your history now. Native migrations take years.
NIST has standardized ML-DSA, and its draft transition plan disallows today’s classical signatures after 2035. Some ecosystems are starting to add post-quantum validator keys, but a chain is only protected once most of its validators have switched, and every block finalized before that stays classical.
PQC Sidecar does not wait for that. It starts producing post-quantum evidence the day you deploy it, for the chains you depend on.
How it works
Stalls rather than skips. Verifies before it writes.
01 · Follow
Follows a node you operate block by block, using only finalized blocks and validating every field. On any failure it retries the same block; it never skips one.
02 · Select
Certifies every N blocks, plus any block that carries an event you choose, such as a validator-set rotation. The strategy reloads live.
03 · Sign
Signs a canonical message with hedged ML-DSA-65, then verifies the signature against the pinned public key before releasing it.
04 · Publish
Stores each certificate atomically as its own file. Anyone holding the public key can verify it.
- Signature
- ML-DSA-65 · FIPS 204
- Certificate
- ≈ 3.4 KB per checkpoint
- Keys
- Local file or AWS KMS
- Chains
- CometBFT today · adapters on request
- Runtime
- Static Rust binary · scratch container
- License
- BSL 1.1 · commercial for production
Chain support
Adapts to any chain, by design.
The certificate format, signing pipeline, key custody, and verifiers do not depend on any one chain. A certificate commits to a chain id, height, block hash, and consensus commitment. Each chain needs only a node adapter that follows its finalized blocks.
Available now
CometBFT-based chains, including Cosmos SDK chains.
Your chain
A standard adapter for your chain is part of every engagement. Tell me the chain and the node software you run.
Key custody
Keep the signing key out of reach.
Use a locked-down local key file, or an AWS KMS ML-DSA-65 key that never leaves KMS. AWS states that its ML-DSA keys and signing operations run in FIPS 140-3 Security Level 3 validated hardware security modules. Either way, the sidecar checks every signature against the pinned public key before releasing it.
Trust model
Clear about what a certificate proves.
A certificate proves that the holder of a specific post-quantum key attested to a chain, height, block hash, and consensus commitment. It does not by itself prove that the validators finalized the block; the sidecar trusts the node it runs beside. Verifiers pin the operator’s public key, which makes certificates useful as operator-attested evidence for bridges, compliance, and archives.
Status
Tested on Cosmos Hub, and clear about what’s left.
- Version 0.1. Not yet externally audited.
- Live run on Cosmos Hub, where certificate hashes matched the chain. A sample certificate is below.
- AWS KMS backend implemented and tested through the AWS SDK; validation on live KMS keys is in progress.
- Long-running soak testing is underway.
Licensing
Evaluate freely. License for production.
PQC Sidecar is licensed under the Business Source License 1.1, with source access for evaluators. Evaluation, testing, and development are free. Production use needs a commercial license, and each version converts to Apache 2.0 within four years of its release. Every engagement includes hands-on integration help.
Sample certificate
Verify a real Cosmos Hub certificate yourself.
A certificate for Cosmos Hub block 33,481,570, produced live by the sidecar, with its public key, the byte format, and a short script that checks it using an independent open-source ML-DSA library. It was signed with a throwaway test key, so it shows the format and the verification path rather than serving as a trust anchor.
- Step 1
Download the sample and install an independent ML-DSA library: pip install dilithium-py. - Step 2
Run python3 verify_sample.py on the certificate and public key. It reports the signature valid; change any byte and it fails. - Step 3
Look up block 33,481,570 on any Cosmos Hub explorer or RPC node. The block hash and validator-set hash match the certificate.
Prefer TypeScript? The open-source verifier checks it too: npx @exocognosis/pqc-sidecar-verify --certificate cosmoshub-4-33481570.pqcc --public-key public_key.hex (GitHub, npm). The byte layout is specified in FORMAT.md.
Engagements
Start an engagement for the chain you rely on.
Tell me the chain and who needs the proof. I’ll tell you whether the sidecar fits and what an engagement involves, including the adapter your chain needs.
rick@dytallix.com