Sendin ID parameter in encrypted form

Question

How can we Send the ID parameter in encrypted form?? in 

below code:-

public  GetHelpVideo(int ID)
{
    try
    {
        HelpContent obj = db.HelpContents.Find(ID);
        string FileName = string.Empty;
        FileName = obj.FileName;
        if (!string.IsNullOrEmpty(FileName))
        {
        }