modular addition

My fix is connected with fact that is not always necessary to perform a modulo operation. For example: we have number a = 3, b = 4, modulus = 10. So, the operation would look something like that: (a + b) mod modulus = (3 + 4) mod 10 = 7 mod 10.

I was browsing (ok, lets be honest - Goooogling) the web in order to find some Multiple-Precision Modular Arithmetics algorithms. Our lecturer recomended a very good book - "Handbook of Applied Cryptography".