Solving Linear Equations Modulo a Composite Number

Alternative Title: Put a Ring on It: Solving Matrix Equations Over Z/NZ Recently, I implemented the index calculus algorithm for computing discrete logs (i.e. solving a=bx mod N), in order to understand it better. The trickiest part, by far, was figuring out how to solve systems of linear equations modulo N, where N is an arbitrary integer which may not be prime. Web search turned up a number of…