The ENCFS6_CONFIG environment variable is used by EncFs to allow the .encfs6.xml to be stored anywhere, not just at the root of the encrypted folder.
This would be a fantastic feature since having the .encfs6.xml file stored with the encrypted data gives a possible intruder a lot of information he/she could use.
BoxCryptor does not support the ENCFS6_CONFIG environment variable, but you can supply the path to the config file as a command line parameter.
You can find more information in the manual:
Unfortunately this option is not very practical because it is not supported on the ipad or iphone, right?
correct on android too - but I'm sure these guys will allow us to store the file locally on the phones in the long term, just a matter of time I guess
Yes, the "alternative configuration file" option is currently not supported in our mobile apps for Android and iOS - but it's on our todo list and we'll implement it also in the mobile apps as fast as possible.