Certificate Verification

Verify a DNSign Certificate

Enter a certificate ID below to confirm document authenticity directly from the DN Deliveries servers. No email trust required.

Certificate Lookup

Your certificate ID can be found printed on the DN Deliveries PDF certificate, or by scanning the QR code embedded in the document.

Alternatively: Scan the QR code printed on the certificate PDF with your phone camera. It will take you directly to the verification result page.

Verification endpoint
https://sign.dn-deliveries.de/signcert.php?sign_id={certificate_id}

HOW SERVER VERIFICATION WORKS

01
You enter the certificate ID

You provide the unique reference ID from the certificate (e.g. found on the printed PDF or via QR scan).

02
Request is sent to our servers

Your browser sends the ID to sign.dn-deliveries.de — the same origin that issued the original certificate.

03
Integrity check is performed

The server fetches the original certificate record and runs a hash comparison to detect any tampering.

04
Result is displayed

You see the full certificate details with a clear status: Valid, Tampered, or Not Found.

Why server-side verification matters

The QR code approach solves the fundamental problem of email-attachment trust.

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The problem with static PDFs

A PDF attachment sent via email can be replaced, edited, or spoofed. Recipients have no way to know if the file they received is the original, unmodified version.

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Trust anchored to the origin server

DNSign certificates include a QR code that links to our server — not a local file. Verification is always performed against the authoritative source.

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Hash-based tamper detection

Every certificate is stored with a cryptographic hash. If any field — signature, timestamp, IP — is changed after issuance, the verification will fail.

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Immutable timestamp

The signing timestamp is recorded at server time and cannot be altered retroactively. You always know exactly when a document was signed.