when you do this operation (first exponentiate, then modulu) it will give a number 0-10, which is the rest of the division
example
when you know the result, you can not determine the a. There are many a for which this works
this result (2) can be used as a starting point for another operation
overall this was
Now, you can also do these calculations in reverse and the result will be the same as above
Why does this work?