The behaviour of these functions is affected by settings in php.ini.
| Name | Default | Changeable | Changelog | 
|---|---|---|---|
| blenc.key_file | /usr/local/etc/blenckeys | PHP_INI_ALL | 
Here's a short explanation of the configuration directives.
blenc.key_file
     string
    It's the location where BLENC can find the file containing a list of available decryption keys. This file must be readable by webserver.