tent of the document creator by restricting user access to an encrypted PDF file according to

the permissions contained in the file.

7.2.2 PDFlib                 

PDF_begin_document( )   

userpassword    masterpassword   

>                                                                                                

>                                                                                                                                        

>                                                                                                   

ASCII     

A                                                                         

A                                                                     

space                 

A                                   

A                                  

>                                                                                 

>                                                                                 

>                                                                                            

PDF_begin_document( )   

permissions                                      

permissions     

masterpassword                                                    

188

7   

:                    

PDF