4. Encrypt your PDF files, step 1. You can select one or a batch of PDF files to encrypt. Encrypted files will be placed in an Output Folder, with a log file. Files will be encrypted with 128-bit RC4 encryption according to the PDF specification, unless you check the box for 40-bit encryption, which will make the files compatible with Adobe Acrobat 4. The keys are stored securely on the Publisher3 PermissionServer, not in the files themselves, and are transmitted over SSL for temporary access to documents by your users. The FileOpen client plug-in checks back with the Publisher3 PermissionServer every time the user opens or prints the document, unless Offline Permissions have been granted.