using System;

using System.IO;

using System.Security.Cryptography;

using System.Text;

using System.Linq;

using System.Numerics;

using System.Collections.Generic;

​

public class Program

{

    public static void Main() {  

        Console.WriteLine("Enter text that needs to be encrypted..");  

        var nextChallenge="BLME1234";

        var  hexString = string.Join("",nextChallenge.Select(c => String.Format("{0:X2}", Convert.ToInt32(c))));

        Console.WriteLine(hexString);

        string data =hexString; //Console.ReadLine();  

        Apply3DES(data);  

        Console.WriteLine("End");  

    }  

    static void Apply3DES(string raw) {  

        try {  

            // Create 3DES that generates a new key and initialization vector (IV).  

            // Same key must be used in encryption and decryption  

            using(TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider()) {  

                // Encrypt string  

                byte[] encrypted = Encrypt(raw, tdes.Key, tdes.IV);  

                // Print encrypted string  

                Console.WriteLine(Convert.ToBase64String(encrypted));

                Console.WriteLine(System.Text.Encoding.UTF8.GetString(encrypted));  

                // Decrypt the bytes to a string.  

                string decrypted = Decrypt(encrypted, tdes.Key, tdes.IV);  

                // Print decrypted string. It should be same as raw data  

                Console.WriteLine(decrypted);  

            }  

        } catch (Exception exp) {  

            Console.WriteLine(exp.Message);  

        }  

    }  

    static byte[] Encrypt(string plainText, byte[] Key, byte[] IV) {  

        byte[] encrypted;  

        // Create a new TripleDESCryptoServiceProvider.  

        using(TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider()) {  

            // Create encryptor  

            ICryptoTransform encryptor = tdes.CreateEncryptor(Key, IV);  

            // Create MemoryStream  

            using(MemoryStream ms = new MemoryStream()) {  

                // Create crypto stream using the CryptoStream class. This class is the key to encryption  

                // and encrypts and decrypts data from any given stream. In this case, we will pass a memory stream  

                // to encrypt  

                using(CryptoStream cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write)) {  

                    // Create StreamWriter and write data to a stream  

                    using(StreamWriter sw = new StreamWriter(cs))  

                    sw.Write(plainText);  

                    encrypted = ms.ToArray();  

                }  

            }  

        }  

        // Return encrypted data  

        return encrypted;  

    }  

    static string Decrypt(byte[] cipherText, byte[] Key, byte[] IV) {  

        string plaintext = null;  

        // Create TripleDESCryptoServiceProvider  

        using(TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider()) {  

            // Create a decryptor  

            ICryptoTransform decryptor = tdes.CreateDecryptor(Key, IV);  

            // Create the streams used for decryption.  

            using(MemoryStream ms = new MemoryStream(cipherText)) {  

                // Create crypto stream  

                using(CryptoStream cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read)) {  

                    // Read crypto stream  

                    using(StreamReader reader = new StreamReader(cs))  

                    plaintext = reader.ReadToEnd();  

                }  

            }  

        }  

        return plaintext;  

    }  

}