Simple Text Cypher to Obscure data

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roger_wgnr

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Since I am fairly new to this forum I could not post this to the Code Library.
I posted it on Extreme VB talk and thought someone here may find it of use also.

This is a simple class to encode and decode lines of text. I find it very usefull to keep prying eyes from data (as long as true security is not an issue) such as file locations and specific program data that I save to data files. While the Encoding is simple and can be broken there are steps that make it harder. Such as using a different key for each encoded line. This helps hide the method used and adds complexity to the process of trying to break it.

However, I want to make it plain that this does not provide secure encryption.
This is more of a method to obscure data for privacy.
Visual Basic: 
Public NotInheritable Class CypherText
    ' Prevent the compiler from creating a default public constructor.
    Private Sub New()

    End Sub
    Public Shared Function EnCode(ByVal ToEnCode As String, ByVal KeyCode As String) As String
        Dim MyReturn As String = ""
        'Convert string to Character array
        Dim MyArray() As Char = ToEnCode.ToCharArray
        Dim Result As String
        'Loop through Array and alter the character
        For MyLoop As Integer = 0 To MyArray.Length - 1
            Result = Chr(Asc(MyArray(MyLoop)) Xor Asc(KeyCode))
            'Do not alter if it results in a Carrage Return or Line Feed
            If Result = Chr(13) Or Result = Chr(10) Then
                MyReturn = MyReturn & Chr(Asc(MyArray(MyLoop)))
            Else
                MyReturn = MyReturn & Result
            End If
        Next
        Return KeyCode & MyReturn
    End Function
    Public Shared Function DeCode(ByVal ToDeCode As String) As String
        Dim MyReturn As String = ""
        Dim Result As String
        'First Character is the Encoding Key
        Dim KeyCode As String = ToDeCode.Substring(0, 1)
        'Convert string to Character Array
        Dim MyArray() As Char = ToDeCode.ToCharArray
        'Loop through all but first character and convert back to original character
        For MyLoop As Integer = 1 To MyArray.Length - 1
            Result = Chr(Asc(MyArray(MyLoop)) Xor Asc(KeyCode))
            'If result is a Carrage Return oR Line Feed it was not encrypted
            If Result = Chr(13) Or Result = Chr(10) Then
                MyReturn = MyReturn & Chr(Asc(MyArray(MyLoop)))
            Else
                MyReturn = MyReturn & Result
            End If
        Next
        Return MyReturn
    End Function
End Class
Now to call the methods I use the following
Code: 
Const KeyVal As String = "abcdefghijklmnopqrstuvwxyz0123456789[]?/><!@#$%^&*()ABCDEFGHIJKLMNOPQRSTUVWXYZ"
Public RndKey As New Random


Dim EncodedTextVariable As String
EncodedTextVariable = CypherText.EnCode("Text to encode Here", KeyVal.Substring(RndKey.Next(0, 77), 1)


Dim OriginalText As String
OriginalText = CypherText.DeCode(EncodedTextVar)

Hope this will be of use :D
 
Let me start by saying I am not trying to be rude, but why create something like this when secure encryption is readily accessible in the runtime and can be implemented with as little or less code?
 
PrOpHeT said:
Let me start by saying I am not trying to be rude, but why create something like this when secure encryption is readily accessible in the runtime and can be implemented with as little or less code?
Click to expand...
Well I'll tell you why I did this. First, this is something I developed when I was using VB6 which did not have the secure encryption available without using API's and getting fairly involved.

Second, This is an alternative that can be included within the code that will not be dependant on any external library. While this does not have any real impact when dealing with the .NET framework. it is an alternative if you are wanting some type of stand alone program.

Third, I always like to have alternatives. I have had issues when trying to use System.Security.Cryptography (But most of that I am sure is my inexperience with .NET)

Fourth, Sometimes it's just looking for a different way of doing things.

My reason was I was looking for a method that I needed to function easily on several platforms with several languages (The code is easy to develop in any language) and in some cases on systems where .NET was not going to be an alternative. This was used in programs using Foxpro, VB6, C++ (Unmanaged), and VB 2005.
 
The title of the post says that it is only intended to obscure data -- The .NET Cryptography Library may be slight overkill in this situation.
 
This is a similar method, however you use the same method for "encrypting" and "decrypting"

C#: 
            public static String Crypt(String sInput)
            {
                // your integer key here, lower values will leave "readable" text, higher will be unprintable..generally speaking
                int iKey = 64;
                System.Text.StringBuilder sbInput = new StringBuilder(sInput, sInput.Length);
                System.Text.StringBuilder sResult = new StringBuilder(sInput.Length);
                for (int i = 0; i < sbInput.Length; i++)
                {
                    sResult.Append((Char)(sbInput[i] ^ iKey));
                }
                return sResult.ToString();
            }
 
Nate, Your method is pretty much what mine is the reason for seperate encode and decode functions is I developed my to encode lines of text and as such I wanted to make it where if several lines of text had similar data the obscured text would not reflect it. By using a random character from the 77 character Keyval constant results in each line having different encodings.

There are a lot of ways to do something like this this was just an exercise for me in getting a function to work the same in .NET as I had working in VB6 so that files encoded in VB6 apps could be read in .NET. I also find doing things like this often help me learn new aspects of the language.

Prophet,

No offense taken (I wondered why I needed this when I first did it)
 
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