Encryption !!!

I know that I have to use System.Security.CreateEncryptor
but can someone plz give me an example? :p
Lets say I have a text file and I want to encrypt the data in the file by using a "key" for the enctyption. How can I do that?

I will appriciate if anyone can show a little example for me, I cant figure it out:(

I saw this thread and it made me think, so after a few hours I came up with this....

Create a new vb app and add a module, erase all the pre generated code and place this code inside... then on the properties of the form set the "startup object" to point to sub main

Code:

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Imports System
Imports System.Text
Imports System.Security.Cryptography

Module Module1

  Private RSA As New RSACryptoServiceProvider()
  Private KeyInfo As RSAParameters = RSA.ExportParameters(False)
  Private AE As ASCIIEncoding = New ASCIIEncoding()

  Sub Main()
    Dim StrToEncode As String = "This is the text that will be encrypted."
    Dim EncodedStr() As Byte ' This is the Array that will hold the Encrypted Data


    ' Display the Test to be encrypted
    MsgBox("String To Be Encrypted:" & vbCrLf & vbCrLf & StrToEncode)

    ' Encode the Data
    EncodedStr = DataEncrypt(StrToEncode)

    ' Do something with this Encrypted Data
    MsgBox("String Encoded:" & vbCrLf & vbCrLf & AE.GetString(EncodedStr) & vbCrLf & vbCrLf)

    ' Decode the Data
    StrToEncode = DataDecrypt(EncodedStr)

    'Display the Decrypted String to a Message Box
    MsgBox("String Decoded:" & vbCrLf & vbCrLf & StrToEncode)
  End Sub

  Private Function DataEncrypt(ByVal RawData As String) As Byte()
    Dim ByteArray() As Byte = AE.GetBytes(RawData)
    DataEncrypt = RSA.Encrypt(ByteArray, False)
  End Function

  Private Function DataDecrypt(ByVal RawData As Byte()) As String
    Dim ByteArray() As Byte = RSA.Decrypt(RawData, False)
    DataDecrypt = AE.GetString(ByteArray)
  End Function

  Private Function GetParamVal(ByVal RawData As Byte()) As String
    Dim i As Integer = 0
    GetParamVal = "{"
    For i = 0 To UBound(RawData)
      If i = UBound(RawData) Then
        GetParamVal = GetParamVal & RawData(i)
      Else
        GetParamVal = GetParamVal & RawData(i) & ", "
      End If
    Next
    GetParamVal = GetParamVal & "}"
  End Function

End Module

---

I didn't have the time to write the extra code that needs to save the "KeyInfo" data but I wrote a function that can turn each member of the class into a string for storage just call the GetParamVal function with the KeyInfo.propertyname and it will return the property in a string type, if you wish to access the encrypted data you will need the exact keyinfo data when the string was encrypted.

Hope this helps, if not well at least I learned something about encryption....

Another thing you could do is use the HashTable class to create your own encryption scheme.