GoGreen PC TuneUp™
Learn More

this is how we code sign our software and ssl encrypt our websites from our affiliate partner SSL.com


myBlog Home

Back to Blog MTNCOMP

RNGCryptoServiceProvider and running odds

by Andy Flagg, Publication Date: Tuesday, October 15, 2019
View Count: 251, Keywords: RNGCryptoServiceProvider, Random, C++, C#, Hashtags: #RNGCryptoServiceProvider #Random #C++ #C#

We had to quickly test some crypto random number generation for salt+hash functionality for another system.
This came from a Microsoft sample and we just wanted to test it.. not bad...

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

using System.IO;
using System.Security.Cryptography;

namespace WindowsFormsApp_RNGSP
    public partial class Form1 : Form
        public Form1()

        private static RNGCryptoServiceProvider rngCsp = new RNGCryptoServiceProvider();
        private void Form1_Load(object sender, EventArgs e)
            const int totalRolls = 25000;
            int[] results = new int[6];

            // Roll the dice 25000 times and display
            // the results to the console.
            for (int x = 0; x < totalRolls; x++)
                byte roll = RollDice((byte)results.Length);
                results[roll - 1]++;
            for (int i = 0; i < results.Length; ++i)
                Console.WriteLine("{0}: {1} ({2:p1})", i + 1, results[i], (double)results[i] / (double)totalRolls);


        public static byte RollDice(byte numberSides)
            if (numberSides <= 0)
                throw new ArgumentOutOfRangeException("numberSides");

            // Create a byte array to hold the random value.
            byte[] randomNumber = new byte[1];
                // Fill the array with a random value.
            while (!IsFairRoll(randomNumber[0], numberSides));
            // Return the random number mod the number
            // of sides.  The possible values are zero-
            // based, so we add one.
            return (byte)((randomNumber[0] % numberSides) + 1);

        private static bool IsFairRoll(byte roll, byte numSides)
            // There are MaxValue / numSides full sets of numbers that can come up
            // in a single byte.  For instance, if we have a 6 sided die, there are
            // 42 full sets of 1-6 that come up.  The 43rd set is incomplete.
            int fullSetsOfValues = Byte.MaxValue / numSides;

            // If the roll is within this range of fair values, then we let it continue.
            // In the 6 sided die case, a roll between 0 and 251 is allowed.  (We use
            // < rather than <= since the = portion allows through an extra 0 value).
            // 252 through 255 would provide an extra 0, 1, 2, 3 so they are not fair
            // to use.
            return roll < numSides * fullSetsOfValues;

more to come...

if you found this article helpful, consider contributing $10, 20 an Andrew Jackson or so..to the author. more authors coming soon
FYI we use paypal or patreon, patreon has 3x the transaction fees, so we don't, not yet.

© 2021 myBlog™ v1.1 All rights reserved. We count views as reads, so let's not over think it.