Upload a document and watch all three layers in action

First it audits: which algorithms it uses and how long they protect against a quantum computer capable of running Shor's algorithm, not just against a classical attacker. Then you can seal it for real with a hybrid classical and post-quantum evidence record (ML-DSA-65, NIST's standard against that threat), downloadable and yours, free. And finally you can check whether the CA that signed it was still trustworthy on the exact date of signing, against Europe's historical trust list archive. The analysis runs on the open engine arqasign-audit. Nothing is stored: every file is analyzed and discarded.