Tangle is a product that allows you to easily manage the security of pdf documents you own. The app allows you to set up the security you want to implement on your pdf documents, making them secure to send to external parties. The app applies security you want to implement and then allows you to share the secured document. Some of the features of the app are:

Password protect a PDF document
Allow / Disallow assembly of a PDF document
Allow / Disallow extraction of a pdf document
Allow / Disallow modification of a pdf document
Allow / Disallow printing of a pdf document
Allow / Disallow printing a degradable version of the document
Share a secure version of the document
Scan and protect a document