JSignPdf is a Java application which adds digital signatures to PDF documents. It can be used as a standalone application or as an Add-On in OpenOffice.org. JSignPdf is open-source software and can be freely used in both private and business sectors.
visible signatures - image and/or description located visualy in a PDF file (page and position can be specified)
several different keystore types (as provided by Java)
timestamps from authority in signature (TSA)
certificate validation through CRL and/or OCSP
setting certification level
setting hash algorithm
PDF encryption and setting rights
comprehensive Swing GUI
support for batch processing (controlled by command line arguments, without GUI)
FreewareFiles tested JSignPdf 1.4.4 on 2013-02-08 using leading
antivirus scanners and found it 100% Clean. It does not contain any form
of malware, spyware, viruses, trojans, etc. We will re-test each updated
version and remove the award as well as the program if found infected.