Echoding and decoding config values

Hi all, I want to know the encoding and decoding phenomenon of oxid esales. I wonder how values are being stored in oxconfig table. They are encrypted in such a way that I haven’t seen before. I went to see the procedure in oxshop_config class. I see a query fetching the config values and decoding using a function

$myConfig->getConfigParam( 'sConfigKey' )

.
I have not seen any variable in whole database and files. I wonder how it is set. I echoed the query and the value of above function is

fq45QS09_fqyx09239QQ

.

I checked in different browsers with different sessions this value remain same. I even tested on another system with new installation but it remain same. When I use this string it successfully decodes the value. I want to know that if this value is constant and used for all installations? If it changes then from where I can get the value. When I use

$myConfig->getConfigParam( 'sConfigKey' )

in my module files in returns nothing.
Can any one guide me from where I can get this variable?