Visual Basic Code / Tutorial: How to Encrypt / Decrypt Using

'-----------------------------ENCRYPT

Imports System.IO
Imports System.Security.Cryptography

Module Encrypt

    Sub EncryptText()
        Try
            Dim EncryptStream As New FileStream("C:\somePath\Test.txt", FileMode.Open)
            Dim RMCrypto As New RijndaelManaged()
            Dim key As Byte() = {&H1, &H2, &H3, &H4, &H5, &H6, &H7, &H8, &H9, &H10, &H11, &H12, &H13, &H14, &H15, &H16}
            Dim IV As Byte() = {&H1, &H2, &H3, &H4, &H5, &H6, &H7, &H8, &H9, &H10, &H11, &H12, &H13, &H14, &H15, &H16}
            Dim CryptStream As New CryptoStream(EncryptStream, RMCrypto.CreateEncryptor(key, IV), CryptoStreamMode.Write)
            Dim sWriter As New StreamWriter(CryptStream)

            sWriter.WriteLine(Form1.TextBox1.Text)
            MsgBox("The plaintext has been converted to ciphertext.", MsgBoxStyle.Information, "Encrypted Text")

            sWriter.Close()
            CryptStream.Close()
            EncryptStream.Close()

        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Exclamation, "Encrypting Error")
        End Try

    End Sub

End Module




'--------------------------DECRYPT

Imports System.IO
Imports System.Security.Cryptography

Module Decrypt

    Sub Decyrpt()

        Dim key As Byte() = {&H1, &H2, &H3, &H4, &H5, &H6, &H7, &H8, &H9, &H10, &H11, &H12, &H13, &H14, &H15, &H16}
        Dim IV As Byte() = {&H1, &H2, &H3, &H4, &H5, &H6, &H7, &H8, &H9, &H10, &H11, &H12, &H13, &H14, &H15, &H16}

        Try
            Dim DecryptStream As New FileStream("C:\somePath\Test.txt", FileMode.OpenOrCreate)
            Dim RMCrypto As New RijndaelManaged()
            Dim CryptStream As New CryptoStream(DecryptStream, RMCrypto.CreateDecryptor(key, IV), CryptoStreamMode.Read)
            Dim sRead As New StreamReader(CryptStream)

            Form1.TextBox2.Text = String.Format("The plaintext is: {0} {1}", vbCrLf, sRead.ReadToEnd())
            sRead.Close()
            DecryptStream.Close()

        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Critical, "Decrypting Error")
        End Try
    End Sub

End Module