Dim rsa As New RSACryptoServiceProvider
    Dim xmlKeys As String 'A combination of both the public and     'private _
      keys  
 
 
#Region " Vom Windows Form Designer generierter Code "
 
    Public Sub New()
        MyBase.New()
 
        ' Dieser Aufruf ist für den Windows Form-Designer erforderlich.
        InitializeComponent()
 
        ' Initialisierungen nach dem Aufruf InitializeComponent() hinzufügen
        xmlKeys = rsa.ToXmlString(True)
    End Sub

        api.RSAVerschlüsseln(api.GetKey("Benutzername"), xmlKeys)
        api.RSAEntschlüsseln(rk.GetValue("Benutzername"), xmlKeys)

Function RSAVerschlüsseln(ByVal text As String, ByVal xmlKeys As String)
        'The plaintext message in a byte array
        Dim PlainTextBArray As Byte()
        'The cyphertext message in a byte array
 
 
        Dim rsa As New RSACryptoServiceProvider
 
        xmlKeys = rsa.ToXmlString(True)
 
        'get the message
        Dim message As String = text
 
        If message.Length > 58 Then MsgBox("You must use fewer than 59" & _
          "characters") : Exit Function
 
        'transform message string into a byte array:
        PlainTextBArray = ASCIIEncoding.UTF8.GetBytes(message)
 
        ' Encrypt 
 
        Dim rk As Microsoft.Win32.RegistryKey = _
          Microsoft.Win32.Registry.CurrentUser.OpenSubKey("SOFTWARE\\SAmAs", _
          True)
        rk.SetValue("Benutzername", rsa.Encrypt(PlainTextBArray, False))
        rk.Close()
    End Function

Function RSAEntschlüsseln(ByVal text As Byte(), ByVal xmlKeys As String)
        Dim rsa As New RSACryptoServiceProvider
 
        'Hold both keys in a global variable that will be used in the         
        ' 'decryption procedure   
 
        'get the keys, thereby creating an RSA object that's identical
        ' to the one used in the Form_Load event when the keys were first built
        rsa.FromXmlString(xmlKeys)
        rsa.ToXmlString(False)
        Dim RestoredPlainText As Byte()
 
        'create a byte array and then put the decrypted plaintext into it
        Try
            RestoredPlainText = rsa.Decrypt(text, False)
        Catch ex As CryptographicException
            MsgBox(ex.ToString())
        End Try
 
        Dim test As String
        'Step through the two-byte unicode plaintext, displaying the restored   
        '       'plaintext message
        For i As Integer = 0 To (RestoredPlainText.Length - 1) Step 2
            test &= Chr(RestoredPlainText(i))
        Next i
 
    End Function