From Sybrex Systems:
PDFSign is a stand-alone, fully automatic software application that can append digital signature to PDF documents. To sign PDF documents simply select the PDF file or folder with PDF files, select Digital ID file and push the "Start" button. ThatÃ¢â?¬â?¢s all. The PDF document will signed automatically.
The programÃ¢â?¬â?¢s features are:
ease of use
recursive search for PDF documents.
No additional plug-ins are required to open documents or verify signatures in Adobe Acrobat or Adobe Reader
Apply invisible signatures to a document or a collection of documents
Linearize for Fast Web View
Certificate information in a PKCS #12 file is used to digitally sign the document.
Use Adobe Acrobat or Adobe Reader to verify your signatures.
Not requiring full Adobe Acrobat or Adobe Reader plus the Adobe Document Server for Reader Extension !
The standard signatures produced by PDFSign are interoperable with the Adobe signature format, and can be verified using the freely available Adobe Reader 6.0+, therefore ensuring embedded signatures have the widest possible reach and can be verified by any recipient.
support for PDF format versions to 1.7.
The program is a must have tool for every individual or company that works with PDF documents extensively.