generate random unique key

random_unque_key.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
namespace ConsoleApplication32
{
    class Program
    {
        static HashSet<string> set = new HashSet<string>();
        static void Main(string[] args)
        {
            System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
            sw.Start();
            for (int i = 0; i < 10000000; i++)
            {
                if (false == set.Add(GetUniqueKey()))
                {
                    System.Diagnostics.Debugger.Break();
                }
            }
            sw.Stop();
            Console.WriteLine(sw.Elapsed);
            System.Diagnostics.Debugger.Break();
        }

        private static string GetUniqueKey()
        {
            RNGCryptoServiceProvider crypto = new RNGCryptoServiceProvider();
            byte[] data = new byte[uniqueKeySize];
            crypto.GetNonZeroBytes(data);
            StringBuilder result = new StringBuilder(uniqueKeySize);
            foreach (byte b in data)
            { result.Append(chars[b % (chars.Length - 1)]); }
            return result.ToString();
        }

        private const int uniqueKeySize = 16;
        private static readonly char[] chars = new char[] { '1', '2', '3', '4', '5', '6', '7', '8', '9', '0' };
    }
}