VeryPDF PDF Encrypter for Mac is a powerful application that can encrypt PDF on Mac OS X. With VeryPDF PDF Encrypter for Mac, you can choose two security levels (40-bit and the other is 128-bit) to encrypt PDF. You can also set two types of passwords-user password and owner password. User password can be used to control the opening permission and owner password can be used to control the access permissions such as copying, modifying, and high quality printing. There are two security levels for encrypting your PDF. One is 40-bit encryption supported by PDF 1.3 and later version of PDF formats, and the other is 128-bit encryption supported by PDF 1.4 and later version of PDF formats. Choose 128-bit encryption will make your PDF much safer. You can set just a user password to control the opening permission of your PDF. Only those who know the user password can open your PDF. You can control the access permissions like copying, modifying, and high quality printing, with an owner password. Add stamps on the page header and page footer. Provide multiple position options, enabling you to put your stamp at the top, at the bottom, in the vertical center, at the diagonal-top left or at the diagonal-bottom left. Place the stamp on top of or underneath the original PDF contents.