RC2 object to encrypt and decrypt data in a file in VB.Net

In this tutorial we will learn how to use RC2 object to encrypt and decrypt data in a file.
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This is the method by which we can encrypt and decrypt the data in the file. It is an important part of Security used in VB.Net application.

1. Open visual studio and create a project

2. Add the following assembly on the page

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

3. Now write the following code for Encryption and Decryption

Module
RC2Sample
    Sub Main()
        Try
            Dim RC2alg As RC2 = RC2.Create("RC2")
            Dim sData As String = "My name is yahoo"
            Dim FileName As String = "CText.txt"

 
            EncryptTextToFile(sData, FileName, RC2alg.Key, RC2alg.IV)
            Dim Final As String = DecryptTextFromFile(FileName, RC2alg.Key, RC2alg.IV)
            Console.WriteLine(Final)
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try
        Console.ReadLine()
    End Sub
    Sub EncryptTextToFile(ByVal Data As String, ByVal FileName As String, ByVal Key() As Byte, ByVal IV() As Byte)
        Try
            Dim fStream As FileStream = File.Open(FileName, FileMode.OpenOrCreate)
            Dim RC2alg As RC2 = RC2.Create
            Dim cStream As New CryptoStream(fStream, RC2alg.CreateEncryptor(Key, IV), CryptoStreamMode.Write)
            Dim sWriter As New StreamWriter(cStream)
            sWriter.WriteLine(Data)
            sWriter.Close()
            cStream.Close()
            fStream.Close()
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
        Catch e As UnauthorizedAccessException
            Console.WriteLine("A file error occurred: {0}", e.Message)
        End Try
        Console.ReadLine()
    End Sub
    Function DecryptTextFromFile(ByVal FileName As String, ByVal Key() As Byte, ByVal IV() As Byte) As String
        Try
            Dim fStream As FileStream = File.Open(FileName, FileMode.OpenOrCreate)
            Dim RC2alg As RC2 = RC2.Create
            Dim cStream As New CryptoStream(fStream, RC2alg.CreateDecryptor(Key, IV), CryptoStreamMode.Read)
            Dim sReader As New StreamReader(cStream)
            Dim val As String = sReader.ReadLine()
            sReader.Close()
            cStream.Close()
            fStream.Close()
             Return val
        Catch e As CryptographicException
            Console.WriteLine("A Cryptographic error occurred: {0}", e.Message)
            Return Nothing
        Catch e As UnauthorizedAccessException
            Console.WriteLine("A file error occurred: {0}", e.Message)
            Return Nothing
        End Try
    End Function

End
Module

4. The Encrypted file is store where the project is saved.

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