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

public class Test
{

 public static void Main()
 {
  Console.WriteLine(EncodePassword("Привет мир!"));
  Console.ReadKey();
 }
 
 public static string EncodePassword(string originalPassword)
 {
   Byte[] originalBytes;
   Byte[] encodedBytes;
   MD5 md5;
 
   md5 = new MD5CryptoServiceProvider();
   originalBytes = ASCIIEncoding.Default.GetBytes(originalPassword);
   encodedBytes = md5.ComputeHash(originalBytes);

   return System.Text.RegularExpressions.Regex.Replace(BitConverter.ToString(encodedBytes), "-", "").ToLower();
 }
}