Securing Documents with Digital Signatures Part 3

Digital signature with keyboard

After Part 1 about the basics and legal aspects and Part 2 about the technical background, this third and final article shows the practical use of digital signatures with webPDF.

How Does the Practical Workflow Look in the webPDF Portal?​

With webPDF, employees can convert documents and digitally sign PDFs on all kinds of end devices. Different signature levels are available for this purpose. Signatures, certificates, and timestamps play a central role in long-term archiving. With appropriate certificates, an electronic signature gains legal validity, while timestamps complement the archiving process.

Facts at a Glance​

  • With webPDF, you can use key functions for digitally signing and certifying PDF documents.
  • Local and smart card based certificate stores are supported.
  • PDF documents can be signed centrally on the server.
  • Time-critical documents can be enhanced with timestamps.

How Do You Apply Digital Signatures with webPDF?​

After uploading a document, you choose the position of the signature. Use the feather icon to open the Add Signature dialog. The available options include:

  • Certificates
  • Appearance (use file)
  • Opacity
  • Position
  • Certification level

You can also enter personal, organizational, and local data. After that, the document can be digitally signed.

When you click Execute, the PDF is digitally signed. No new document is created. Instead, the existing document is modified. The Digital Signature service is intended only for PDF documents, not for external formats.

Background for Developers: Signature Webservice​

The digital signing function is based on the Signature webservice. You can find the technical coding example here: webPDF Webservices Signature

We also refer to the webPDF Webservices category, where additional coding examples for using the webPDF wsclient library are gradually being published.

What Are Digital Signatures Used For?​

With the signature function, you can digitally sign, electronically sign, or certify PDF documents. A signature confirms the authenticity of the PDF and protects it against tampering. Advanced electronic signatures are important, for example, for electronic invoices or audit-proof archiving.

For signing, an asymmetric cryptographic process is used. This allows documents to be clearly identified. A certificate also protects them from later changes. With webPDF, you can use certificates issued by an official Certificate Authority (CA).

More details: BSI - Digital Signature