Recall the definition of two integers being congruent modulo n for a natural number n
Determine whether [two integers a and b] are congruent modulo [a given natural number n]
Recall the definition of a residue class modulo n
Perform modular reduction modulo n
Perform [various modular arithmetic operations] in Z n including addition, subtraction and multiplication (mod n)
Determine which elements of Z n have multiplicative inverses, and find these multiplicative inverses when they exist [for a particular natural number n]
Use the Square-and-Multiply Algorithm to perform modular exponentiation