Locklizard Safeguard PDF Security is a powerful security solution for protecting PDF documents from unauthorized access and distribution. It allows users to create secure PDF documents that can be opened only with a valid user ID and password. The user ID and password are encrypted using strong encryption algorithms, making it virtually impossible for unauthorized users to gain access to the documents. Locklizard Safeguard PDF Security also offers a number of other features, such as watermarking, digital rights management (DRM) controls, and customizable security settings. The security settings can be set to allow or deny access to the document based on user permission levels, and the DRM controls allow users to control who can print, copy, and/or share the document. With Locklizard Safeguard PDF Security, users can be confident that their sensitive documents are secure and only accessible to those with the proper credentials.
Warning The PDFCore.com site has a bad reputation on WOT (http://www.mywot.com/en/scorecard/pdfcore.com) and SiteAdvisor identifies it as suspicious.
PDFTK Builder
QPDF
iSafePDF
PDFTools
GSView
PDF Architect
Advanced PDF Utilities Free
LockPDF
FileOpen RightsManager
Ignissta PDF Lock Unlock
PDF Protector
Wonderfulshare PDF Protect Pro
CapLinked FileProtect
The last discontinued version, 1.3, was released in August 2007. It can still be downloaded from the official website.