Download free trial of PDF locker to batch protect PDF files. PDF security software set user password on bulk PDF documents which is used to open PDF file while reading. Application provides 128 bit RC4 and 40 bit RC4 encryption level security. User can set own user as well owner password. Once an owner password is applied, no one can modify the PDF. Tool sets various restrictions on PDF files like PDF text copying, PDF printing, page extraction etc. By applying user password, user need to enter PDF open password for reading and by applying owner password, no one can change the document. Software does not require any plug-in to download. Features: # Tool provides inbuilt user help manual. # PDF locker supports all latest Windows operating systems including Win XP, Vista and 7. # Application is able to set both user password as well owner password. # PDF encryption software is user friendly tool. # Application provides PDF right click context menu option as shortcut.