Encrypt and decrypt a string

there are many methods one of is following
add following name space
Using System.Security.Cryptography
remember whenever you are encrypting and decrypting same word you will have 
to add same key parameter 
it means if you are encrypting word csharp and sending parameter c in 
string strKey  parameter then while decrypting also you will havew to pass same key
in decrypt function with decrypt string  
public static string Encrypt(string strToEncrypt, string strKey) { try { TripleDESCryptoServiceProvider objDESCrypto = new TripleDESCryptoServiceProvider(); MD5CryptoServiceProvider objHashMD5 = new MD5CryptoServiceProvider();  byte[] byteHash = null; byte[] byteBuff = null; string strTempKey = strKey;  byteHash = objHashMD5.ComputeHash(ASCIIEncoding.ASCII.GetBytes(strTempKey)); objHashMD5 = null; objDESCrypto.Key = byteHash; objDESCrypto.Mode = CipherMode.ECB; //CBC, CFB byteBuff = ASCIIEncoding.ASCII.GetBytes(strToEncrypt); return Convert.ToBase64String(objDESCrypto.CreateEncryptor().TransformFinalBlock(byteBuff, 0, byteBuff.Length)); } catch (Exception ex) { return "Wrong Input. " + ex.Message; } }



public static string Decrypt(string strEncrypted, string strKey) { try { TripleDESCryptoServiceProvider objDESCrypto = new TripleDESCryptoServiceProvider(); MD5CryptoServiceProvider objHashMD5 = new MD5CryptoServiceProvider();  byte[] byteHash = null; byte[] byteBuff = null; string strTempKey = strKey;  byteHash = objHashMD5.ComputeHash(ASCIIEncoding.ASCII.GetBytes(strTempKey)); objHashMD5 = null; objDESCrypto.Key = byteHash; objDESCrypto.Mode = CipherMode.ECB; //CBC, CFB byteBuff = Convert.FromBase64String(strEncrypted); string strDecrypted = ASCIIEncoding.ASCII.GetString(objDESCrypto.CreateDecryptor().TransformFinalBlock(byteBuff, 0, byteBuff.Length)); objDESCrypto = null;  return strDecrypted; } catch (Exception ex) { return "Wrong Input. " + ex.Message; } }