Data Encryption (Triple DES)

Here is a module that i created to encrpyt/decrypt data using VB's TripleDESCryptoServiceProvider. Hope this may be useful. I have commented code as much as possible so that you may be able to understand it a bit better:

Code:

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Module Data

    'Declare key and initialization vector to use for encryption'

    Private Key() As Byte = {26, 15, 5, 46, 98, 21, 2, 36, 19, 4, 22, 50, 42, 14, 24, 18, 34, 16, 82, 76, 65, 91, 54, 78}
    Private InitializationVector() As Byte = {65, 110, 68, 26, 69, 178, 200, 219}

    Public Function Encrypt(ByVal Text As String) As Byte()

        'Create UTF8 encoder to convert text into byte array'

        Dim UTF8Encoder As System.Text.UTF8Encoding = New System.Text.UTF8Encoding()
        Dim TextBytes() As Byte = UTF8Encoder.GetBytes(Text)


        'Create triple DES service provider'

        Dim TDESProvider As System.Security.Cryptography.TripleDESCryptoServiceProvider = New System.Security.Cryptography.TripleDESCryptoServiceProvider

        Dim CryptoTransform As System.Security.Cryptography.ICryptoTransform = TDESProvider.CreateEncryptor(Key, InitializationVector)


        'Create memory stream to store encrypted data'

        Dim EncryptionStream As System.IO.MemoryStream = New System.IO.MemoryStream
        Dim CryptoStream As System.Security.Cryptography.CryptoStream = New System.Security.Cryptography.CryptoStream(EncryptionStream, CryptoTransform, Security.Cryptography.CryptoStreamMode.Write)


        'Write the encrypted information to the stream. Flush the information when done to ensure everything is out of the buffer'
        CryptoStream.Write(TextBytes, 0, TextBytes.Length)
        CryptoStream.FlushFinalBlock()
        EncryptionStream.Position = 0


        'Read the stream back into a Byte array and return it to the calling method'

        Dim Result(EncryptionStream.Length - 1) As Byte
        EncryptionStream.Read(Result, 0, EncryptionStream.Length)
        CryptoStream.Close()
        Return Result

    End Function


    Public Function Decrypt(ByVal TextBytes() As Byte) As String

        'Create triple DES service provider'

        Dim TDESProvider As System.Security.Cryptography.TripleDESCryptoServiceProvider = New System.Security.Cryptography.TripleDESCryptoServiceProvider

        Dim CryptoTransform As System.Security.Cryptography.ICryptoTransform = TDESProvider.CreateDecryptor(Key, InitializationVector)


        'Create memory stream to store decrypted data'

        Dim DecryptionStream As System.IO.MemoryStream = New System.IO.MemoryStream
        Dim CryptoStream As System.Security.Cryptography.CryptoStream = New System.Security.Cryptography.CryptoStream(DecryptionStream, CryptoTransform, Security.Cryptography.CryptoStreamMode.Write)

        CryptoStream.Write(TextBytes, 0, TextBytes.Length)
        CryptoStream.FlushFinalBlock()
        DecryptionStream.Position = 0


        'Read contents of memory stream, convert back to a string and return result'

        Dim result(DecryptionStream.Length - 1) As Byte

        DecryptionStream.Read(result, 0, DecryptionStream.Length)
        CryptoStream.Close()


        'Create UTF8 Encoder to convert bytes back to string'

        Dim UTF8Encoder As System.Text.UTF8Encoding = New System.Text.UTF8Encoding()

        Return UTF8Encoder.GetString(result)

    End Function

End Module

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Please note that that you can use any numbers for your key and initialization vector but the key must only be 24 bytes (24 number) and the initialization vector 8 bytes (8 numbers).

edit sorry, wrong topic

Thanks a lot! This was very helpful.

Nice one.