Your electronic signature is valid today. Will it still be in twenty years?
Once a quantum computer powerful enough exists, any RSA or ECDSA signature made today can be forged with a backdated timestamp. Documents with a legal duty of retention (registries, notaries, medical records) are signed with those algorithms right now. Arqasign audits a document's real risk, seals it with a downloadable post-quantum cryptographic proof, and checks whether the entity that signed it was still trustworthy on the exact date of signing.
We audited Spain’s Official State Gazette (BOE): RSA-2048 signature with a SHA-1 digest. Real cryptographic protection, until 2030.
Audit
Upload a signed document and find out which algorithms it uses and how long it stays defensible.
Seal
Generate a real evidence record (RFC 4998) with a hybrid classical and post-quantum signature. Downloadable, free, unlimited use.
Verify
Check whether the entity that signed the document was still trustworthy on the exact date of signing, against Europe's historical trust list archive.
Breaking an RSA-2048 signature with Shor’s algorithm used to require, according to the 2019 reference estimate (Gidney and Ekerå), about twenty million physical qubits with error correction. In May 2025, a new result from Google cut that figure to under a million: twenty times fewer, in six years. The most advanced processors today (Google Willow, IBM Heron) work with hundreds of qubits, not millions, and IBM’s own public roadmap points to a fault-tolerant system of 200 logical qubits by 2029. The gap is still real. But it has shrunk twenty-fold in half a decade, and NIST already sets 2030 as the deadline to stop recommending RSA and ECDSA, and 2035 to ban them outright (NIST IR 8547). A notarial deed or a medical record signed today has to remain defensible past that date.
Why this breaks a signature already made, not just new ones →