Encryption and Decryption using TripleDES

Following is the helper class for encrypting or decrypting a string using TripleDES method.

using System;
using System.Security.Cryptography;
using System.Text;

namespace CareerBox
{
    public class CryptoHelper
    {
        static TripleDESCryptoServiceProvider cryptDES3 = new 

TripleDESCryptoServiceProvider();
        static MD5CryptoServiceProvider cryptMD5Hash = new MD5CryptoServiceProvider();

        static string key = "g0p!P0rt@L";

        public static string Encrypt(string text)
        {
            try
            {
                cryptDES3.Key = cryptMD5Hash.ComputeHash(ASCIIEncoding.ASCII.GetBytes

(key));
                cryptDES3.Mode = CipherMode.ECB;
                ICryptoTransform desdencrypt = cryptDES3.CreateEncryptor();
                byte[] buff = ASCIIEncoding.ASCII.GetBytes(text);
                string Encrypt = Convert.ToBase64String

(desdencrypt.TransformFinalBlock(buff, 0, buff.Length));
                //Replace +,/,= with !,@,# for URL friendly
                Encrypt = Encrypt.Replace("+", "!").Replace("/", "@").Replace("=", 

"$");
                return Encrypt;
            }
            catch
            {
                return "";
            }
        }
        public static string Decyrpt(string text)
        {
            try
            {
                //Replace !,@,# with +,/,=
                text = text.Replace("$", "=").Replace("@", "/").Replace("!", "+");
                byte[] buf = new byte[text.Length];
                cryptDES3.Key = cryptMD5Hash.ComputeHash(ASCIIEncoding.ASCII.GetBytes

(key));
                cryptDES3.Mode = CipherMode.ECB;
                ICryptoTransform desdencrypt = cryptDES3.CreateDecryptor();
                buf = Convert.FromBase64String(text);
                string Decrypt = ASCIIEncoding.ASCII.GetString

(desdencrypt.TransformFinalBlock(buf, 0, buf.Length));
                return Decrypt;
            }
            catch
            {
                return "";
            }

        }
    }
}

You can use your own phrase as key.
Encrypt function will return a string contains A-Z, a-z, 0-9,+,/ and = only as we are converting the encrypted bytes array using Base64 encoding. Here last 3 characters (+,/,=) are not suitable for URLS. So I replaced them with !,@,$ respectively. While decrpting, I simply reverse the replacement.

Gopikrishna