Not every signature is a signature
An image drawn over a PDF looks like a signature, but proves nothing: anyone can copy and paste it. A real digital signature is cryptographic, ties the document to a certificate and becomes invalid if anyone modifies the file after signing.
What PAdES is
PAdES (PDF Advanced Electronic Signatures) embeds a PKCS#7 signature directly into the PDF's structure. The result:
- verifiable in Adobe and other readers;
- tamper-evident: any later change invalidates it;
- contains information about the signer and the moment of signing.
How it works in Voltzzflow
- The owner uploads a certificate
.pfx / .p12, encrypted at rest. - When signing, a popup appears where you pick the certificate.
- Click on the document to place the signature exactly where you want it.
- Apply it, a signed PDF is generated.
When you need a qualified signature (QES)
For contracts with strict legal requirements you can use a qualified signature through a provider with a remote HSM. This needs a separate contract and credentials, but the placement flow stays just as simple.
A digital signature isn't just about compliance, it's also about speed: no more printing, signing and scanning.
The feature is included in the Pro plan.