C# - Text codieren

using System;
using System.Collections.Generic;
using System.Linq;

namespace MechCoding
{
    public static class Coder
    {
        public static string Codieren(string source)
        {
            List<string> Ausgabe = new List<string>();

            Random ran = new Random();
            foreach (var item in source.Split(' '))
            {
                if (item.Count() <=3)
                {
                    Ausgabe.Add(item);
                    continue;
                }
                char first = item[0];
                char last = item[item.Count() - 1];
                char[] list = new char[item.Count() - 2];
                string alpha = item.Remove(0, 1);
                alpha = alpha.Remove(alpha.Count() - 1, 1);
                foreach (var item2 in  alpha )
                {
                    int ini;
                    bool tr = true;
                    while (tr)
                    {
                        ini = ran.Next(0,alpha.Count());
                        if (list[ini] == '\0')
                        {
                            list[ini] = item2;
                            tr = false;
                        }
                    }
                }
                string fertig = "";
                fertig += first;
                foreach (var item2 in list)
                {
                    fertig += item2; 
                }
                fertig += last;
                Ausgabe.Add(fertig);
            }

            string Fertig = "";
            foreach (var item in Ausgabe)
            {
                Fertig += item + " ";
            }
            return Fertig;
        }
    }
}