Imports System.Net.Sockets
Imports System.Threading
Imports System.Security.Cryptography
 
Module Module1
 
    Sub Main()
        Dim TCPListen As New TcpListener(System.Net.IPAddress.Loopback, 11000)
        TCPListen.Start()
 
        ' Checkt die Verbindung
        While Not TCPListen.Pending()
            Console.WriteLine("Warte auf Verbindung ...")
            Thread.Sleep(5000)
        End While
 
        Dim TCP As TcpClient = TCPListen.AcceptTcpClient()
 
        Dim NetStream As NetworkStream = TCP.GetStream()
 
        Dim RMCrypto As New RijndaelManaged
        Dim Key As Byte() = {65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, _
          77, 78, 79, 80}
        Dim IV As Byte() = {65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, _
        78, 79, 80}
 
        Dim CryptStream As New CryptoStream(NetStream,      _
          RMCrypto.CreateDecryptor(Key, IV), CryptoStreamMode.Read)
 
        Dim byteFeld(15) As Byte
        Console.WriteLine(CryptStream.Read(byteFeld, 0, 16) & " Bytes" & _
          "empfangen!")
 
        Console.Read()
 
        NetStream.Close()
        TCP.Close()
 
    End Sub
 
End Module

Imports System.Net.Sockets
Imports System.Security.Cryptography
 
Module Module1
 
    Sub Main()
 
        Dim TCP As New TcpClient("localhost", 11000)
 
        Dim NetStream As NetworkStream = TCP.GetStream()
 
        Dim RMCrypto As New RijndaelManaged
        Dim Key As Byte() = {65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, _
          77, 78, 79, 80}
        Dim IV As Byte() = {65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, _
        78, 79, 80}
        Dim CryptStream As New CryptoStream(NetStream, RMCrypto.CreateEncryptor( _
        Key, IV), CryptoStreamMode.Write)
 
        ' Testdaten
        Dim byteFeld As Byte() = {66, 59, 80}
        CryptStream.Write(byteFeld, 0, byteFeld.Length)
        CryptStream.Flush()
 
        Console.WriteLine("Die Nachricht wurde gesendet.")
 
        ' Wartet auf eine Eingabe
        Console.Read()
 
        CryptStream.Close()
        NetStream.Close()
        TCP.Close()
    End Sub
 
End Module