PQC Hybrid Signing, explained for beginners

PQC Hybrid Signing seals records with today's method and a quantum-resistant one, so they stay tamper-evident for years.

What it is

Digital signatures are what make records tamper-evident. Today's methods are safe, but experts expect large quantum computers to break some of them one day. Records that must stay trustworthy for years (contracts, audit trails, payments) can be collected now and forged later. This is often called "harvest now, decrypt later".

PQC Hybrid Signing signs each record with two methods at once: Ed25519 (today's standard) and ML-DSA-65, a post-quantum method standardised by the US NIST in 2024 (FIPS 204). Both must verify. Change one character of the record and both fail.

An everyday comparison

Two different locks on the same safe, from two different makers: if one design is ever picked, the other still holds.

How it works, in 4 steps

1. A record (here: a payment instruction) is signed with both methods.
2. Both signatures are attached.
3. Checking requires both to verify.
4. Any change to the record fails.

Try it now

Open the three live demo tools → Every button sends a real request to the live product and shows the real answer.

See it on the homepage: PQC Hybrid Signing section →

Who it is for

Organisations keeping signed records for years: finance, legal, government suppliers, and anyone asked about post-quantum plans.

FIRME AI CORPORATION · CAIN-42 is a Byzantine trust fabric. Numbers marked "our own check" were run by us, not by an independent party. Nothing on these pages is a certification.