public class Md5Helper

{

    public static string Md5(string value)

    {

        var result = string.Empty;

        if (string.IsNullOrEmpty(value)) return result;

        using (var md5 = MD5.Create())

        {

            result = GetMd5Hash(md5, value);

        }

        return result;

    }

    static string GetMd5Hash(MD5 md5Hash, string input)

    {

        byte[] data = md5Hash.ComputeHash(Encoding.UTF8.GetBytes(input));

        var sBuilder = new StringBuilder();

        foreach (byte t in data)

        {

            sBuilder.Append(t.ToString("x2"));

        }

        return sBuilder.ToString();

    }

    static bool VerifyMd5Hash(MD5 md5Hash, string input, string hash)

    {

        var hashOfInput = GetMd5Hash(md5Hash, input);

        var comparer = StringComparer.OrdinalIgnoreCase;

        return  == comparer.Compare(hashOfInput, hash);

    }

}