What achow101 says...!

It might be interesting to know what kind of software you have there, so others can be properly warned.
If you have some really old legitimate mining software (from the time when mining with CPUs or GPUs was still possible) the "server key" might be a key from a mining pool which would be used to allocate fractional block rewards to the people running the miners on their computer. But that time is long gone.
Bitcoin mining today is only possible with special-purpose hardware, and mining profitably requires a lot of knowledge and access to cheap electricity.
Just forget about it for the moment (you might look into it again after you have learned about how bitcoin works, but even then you will most likely find that you can't mine bitcoins for profit at home).

Onkel Paul