The Signature995 conforms a PDF-related software suite together with Pdf995 and PdfEdit995 and is the free way to access to encryption of PDF files. It's not exactly free though. You can choose between the sponsored version – for free – in wich you will be seeing ads for Pdf955 and other software produced by the same software company, and the really affordable registered version.
When it's about security this application comes in handy. On an easy-to-use interface consisting on a set of tabs you will be provided of multiple interesting and usefull functions to secure your PDF files, among them:
Encryption: not only PDF files but Microsoft Office and zip files too. Generates a copy of the original document in the same location.
Decryption: decrypts files encrypted with Signature995 if the correct password is supplied. Generates a copy of the original document in the same location.
Sign: signs your documents using your digital certificate. Generates a copy of the original document in the same location.
Co-Sign: adds a signature using your digital certificate to documents that already have been signed.
Verify: verifies and display certificates on signed documents.
