Parallel between a bitstream and source code

Hello,

I have the source code of a design and the bitstream and I have to make sure they are related. I was wondering if with Quartus II (v14.1) there is a verification function.

At first I thought that the checksum would be the same if the same design was compiled n times, but every time I compile the design, the checksum is different.

Thanks in advance for any answer,