Untitled

using System;
using System.Security.Cryptography;
using System.Text;

namespace Hasz
{
    class Program
    {
        static void Main(string[] args)
        {
            string stringKtoryHashuje = "Ala ma kota";
            Console.WriteLine(HashString(stringKtoryHashuje));

            Console.ReadKey();
        }

        static string HashString(string textToHash)
        {
            byte[] data = Encoding.UTF8.GetBytes(textToHash);
            byte[] hash;

            SHA512 shaM = new SHA512Managed();
            
            hash = shaM.ComputeHash(data);

            string wynik = ByteArrayToString(hash);

            return wynik;
        }
         static string ByteArrayToString(byte[] b)
        {
            StringBuilder hex = new StringBuilder(b.Length * 2);
            foreach (byte element in b)
            {
                hex.AppendFormat("{0:x2}", element);
            }
            return hex.ToString();
        }

    }
}