(PECL haru >= 0.0.1)
HaruDoc::setEncryptionMode — Set encryption mode for the document
$mode
   [, int $key_len = 5
  ] )Defines encryption mode for the document. The encryption mode cannot be set before setting the password.
modeThe encryption mode to use. Can be one of the following:
HaruDoc::ENCRYPT_R2 - use "revision2"
         algorithm.
        HaruDoc::ENCRYPT_R3 - use "revision3"
         algorithm. Using this value bumps the version of PDF to 1.4.
        key_len
       The encryption key length in bytes. This parameter is optional and used only
       when mode is HaruDoc::ENCRYPT_R3. The default
       value is 5 (40bit).
      
   Returns TRUE on success.
  
Throws a HaruException on error.