Qausal Reviews & Product Details

Qausal is an e-signature platform built on post-quantum cryptography. Most signing tools use RSA or ECDSA, which a large enough quantum computer will break, and a signature can't be upgraded after it is made. Qausal signs with ML-DSA-65, the algorithm NIST standardised as FIPS 204. It works like any signing tool: upload a PDF, invite one signer or several with roles and a signing order, and follow who has signed. Signers don't need an account. Two things are different. A signed PDF carries its signatures, public keys and digests inside the file, with a downloadable proof bundle, so it can be verified offline with open-source tools and stays verifiable if the vendor disappears. And documents already signed elsewhere can be sealed with a quantum-safe attestation, without changing the original file. There is a free 20-day trial. After that you can pay per signature with no monthly fee, from 48 cents each, or subscribe from $9 AUD a month.