<p>using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.IO;
using System.Xml;
using System.Text.RegularExpressions;

public interface IStringUtilities
{
  string Encrypt(string message, string password);
  string Decrypt(string encryptedMessage, string password);
}

public class Solution : IStringUtilities
{
  public string Encrypt(string message, string password)
  {
    byte[] results;
    System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
    
    var HashProvider = new System.Security.Cryptography.MD5CryptoServiceProvider();
    byte[] TDESKey = HashProvider.ComputeHash(UTF8.GetBytes(password));
    
    var TDESAlgorithm = new System.Security.Cryptography.TripleDESCryptoServiceProvider();
    
    TDESAlgorithm.Key = TDESKey;
    TDESAlgorithm.Mode = System.Security.Cryptography.CipherMode.ECB;
    TDESAlgorithm.Padding = System.Security.Cryptography.PaddingMode.PKCS7;
    
    byte[] dataToEncrypt = UTF8.GetBytes(message);
    
    try
    {
    	var encryptor = TDESAlgorithm.CreateEncryptor();
    	results = encryptor.TransformFinalBlock(dataToEncrypt, 0, dataToEncrypt.Length);
    }
    finally
    {
    	TDESAlgorithm.Clear();
    	HashProvider.Clear();
    }
    
    return Convert.ToBase64String(results);
  }
  
  public string Decrypt(string encryptedMessage, string password)
  {
    byte[] results;
    System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
    
    var hashProvider = new System.Security.Cryptography.MD5CryptoServiceProvider();
    byte[] tdesKey = hashProvider.ComputeHash(UTF8.GetBytes(password));
    
    var tdesAlgorithm = new System.Security.Cryptography.TripleDESCryptoServiceProvider();
    
    tdesAlgorithm.Key = tdesKey;
    tdesAlgorithm.Mode = System.Security.Cryptography.CipherMode.ECB;
    tdesAlgorithm.Padding = System.Security.Cryptography.PaddingMode.PKCS7;
    
    byte[] dataToDecrypt = Convert.FromBase64String(encryptedMessage);
    
    try
    {
    	System.Security.Cryptography.ICryptoTransform decryptor = tdesAlgorithm.CreateDecryptor();
    	results = decryptor.TransformFinalBlock(dataToDecrypt, 0, dataToDecrypt.Length);
    }
    
    finally
    {
    	tdesAlgorithm.Clear();
    	hashProvider.Clear();
    }
    
    return UTF8.GetString(results); 
  }
}
</p>