PortableNotary-an open source software to verify pdf signature PortableNotary is an open source software to verify pdf signature, bases on iText, you can download it from here. PortableNotary permits you to verify pdf signature. It is OS independent and can be used from command line. Leave a Reply Cancel replyYou must be logged in to post a comment. This site uses Akismet to reduce spam. Learn how your comment data is processed.