Creating Digital Signatures with PDFlib PLOP DS PDFlib PLOP DS (Digital Signature) offers all features of PLOP, plus the ability to apply digital signatures to PDF documents.
- PLOP DS can apply standard PDF signatures which can be verified with Adobe Reader or Acrobat 6 and above. Signature support is available in the PLOP DS library and in the command-line tool, and works as follows:
- PLOP DS reads certificates (digital IDs) from standard PKCS#12 or PFX files. On Windows, the certificate store can also be accessed to use certificates which are installed in the system.
- PLOP DS can create signatures in existing signature fields or generate new fields to hold the signature. The generated signatures can be invisible, or visible at a particular location on the page. Several signature properties which will be displayed in Acrobat can be specified, such as the reason of the signature, location, contact info, etc.
- PLOP DS supports all PDF versions up to and including PDF 1.7, the file format of Acrobat 8. Applying a signature can be combined with encryption (user password, master password, or permissions).
For specialized applications the crypto engine built into PLOP DS can be replaced with a custom engine, e.g. to leverage cryptographic hardware or certified cryptographic software modules.
Other Benefits PLOP is PDF/A-aware: if the input document conforms to the PDF/A standard, the output document is guaranteed to still comply with PDF/A. Similarly, PLOP is PDF/X-aware.
Since PLOP accepts PDF input documents from a disk file or directly in memory, it can easily be combined with PDFlib for dynamic PDF generation. For example, using the combination of PDFlib and PLOP DS you can create PDF invoices and sign them before sending them to the customer.