Socket with data transfer in encrypted format

Module Module1

    Sub Main()

        Dim serverSocket As New TcpListener(8888)
        Dim requestCount As Integer

        Dim clientSocket As TcpClient

        serverSocket.Start()
        msg("Server Started")

        clientSocket = serverSocket.AcceptTcpClient()
        msg("Accept connection from client")

        requestCount = 0

        While (True)

            requestCount = requestCount + 1

            '' Data reading from client
            Dim networkStream As NetworkStream = clientSocket.GetStream()

            Dim bytesFrom(clientSocket.ReceiveBufferSize) As Byte
            networkStream.Read(bytesFrom, 0, CInt(clientSocket.ReceiveBufferSize))

            Dim dataFromClient As String = Encoding.ASCII.GetString(bytesFrom)


            msg("Data from client -  " + TripleDES.DecryptString(dataFromClient))
          
            '' Data writting to client
            Dim serverResponse As String = "Server response " + Convert.ToString(requestCount)
            Dim sendBytes As Byte() = Encoding.ASCII.GetBytes(TripleDES.EncryptString(serverResponse))
           
            networkStream.Write(sendBytes, 0, sendBytes.Length)
            networkStream.Flush()

            msg(serverResponse)

        End While


        clientSocket.Close()
        serverSocket.Stop()

        msg("exit")
        Console.ReadLine()

    End Sub

    Sub msg(ByVal mesg As String)
        mesg.Trim()
        Console.WriteLine(" >> " + mesg)
    End Sub

End Module

Public Shared Function SendRequest(ByVal InXML As String, ByRef OutXML As String) As Boolean
        Try
            Dim nwStream As NetworkStream = clientSocket.GetStream()

            '' write to network stream
            Dim outStream As Byte() = Encoding.ASCII.GetBytes(TripleDES.EncryptString(InXML))
            ' Dim outStream As Byte() = Encoding.ASCII.GetBytes(InXML)
            nwStream.Write(outStream, 0, outStream.Length)
            nwStream.Flush()

            '' data reading from server
            Dim inStream(clientSocket.ReceiveBufferSize) As Byte
            nwStream.Read(inStream, 0, CInt(clientSocket.ReceiveBufferSize))

            Dim tmpStr As String = Encoding.ASCII.GetString(inStream)
            OutXML = TripleDES.DecryptString(tmpStr)

            'OutXML = tmpStr

            Return True

        Catch ex As Exception
            OutXML = ex.Message
            Return False

        End Try

    End Function

End Class

Public Class TripleDES

    '' Initilization vector
    Private Shared IV() As Byte = Encoding.UTF8.GetBytes("password")

    '' Encryption key - base 64
    Private Shared EncryptionKey() As Byte = Convert.FromBase64String("rpaSPvIvVLlrcmtzPU9/c67Gkj7yL1S5")

    '' Encryption method
    Public Shared Function EncryptString(ByVal Input As String) As String
        Dim buffer() As Byte = Encoding.UTF8.GetBytes(Input)

        Dim des As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider()
        des.Mode = CipherMode.ECB
        des.Key = EncryptionKey
        des.IV = IV

        Dim output() As Byte = des.CreateEncryptor().TransformFinalBlock(buffer, 0, buffer.Length())

        Return Convert.ToBase64String(output)

    End Function

    '' Descryption method
    Public Shared Function DecryptString(ByVal Input As String) As String
        Dim buffer() As Byte = Convert.FromBase64String(Input)

        Dim des As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider()
        des.Mode = CipherMode.ECB
        des.Key = EncryptionKey
        des.IV = IV

        Dim output() As Byte = des.CreateDecryptor().TransformFinalBlock(buffer, 0, buffer.Length())

        Return Encoding.UTF8.GetString(output)

    End Function


End Class