using System;

using System.Collections.Generic;

using System.Security.Cryptography;

using System.Linq;

using System.Text;

​

public class Program

{

    public static void Main()

    {

        byte Min = 0;

        byte Max = byte.MaxValue;

        Random randNum = new Random();

        byte[] result = new byte[10]; 

        byte[] sha256 = {0x0,0x0};

        var attempts = 0;

        var crypto = new SHA256CryptoServiceProvider();

        do

        {

            attempts++;

            for (int i = 0; i < result.Length; i++)

            {

                result[i] = (byte)randNum.Next(Min, Max);

            }

            sha256 = crypto.ComputeHash(result);

        }while(sha256[0] > 0);

​

        Console.WriteLine("attempts: " + attempts);

        Console.WriteLine("Sha256: " + ByteArrayToString(sha256));

        Console.WriteLine("Result: " + ByteArrayToString(result));

    }

    static string ByteArrayToString(byte[] ba)

    {

        StringBuilder hex = new StringBuilder(ba.Length * 2);

        foreach (byte b in ba)

            hex.AppendFormat("{0:x2}", b);

        return hex.ToString();

    }

}