Multiplication

public ArrayList<Integer> multiplyAbyB(Integer a, Integer b, Integer n, ArrayList<Integer> primes) {
        crt.setFactors(primes);
        crt.setMod(n);
        return crt.getMapping(((a * b) % n));
    }

    public ArrayList<Integer> multiplyAbyBModified(Integer a, Integer b, Integer n, ArrayList<Integer> primes) {
        crt.setFactors(primes);
        crt.setMod(n);
        ArrayList<Integer> aMapping = crt.getMapping(a);
        ArrayList<Integer> bMapping = crt.getMapping(b);
        ArrayList<Integer> result = new ArrayList<>();
        for (int index = 0; index < aMapping.size(); index++) {
            result.add((aMapping.get(index) * bMapping.get(index)) % primes.get(index));
        }
        return result;
    }