[Skunkworks] OT--Counterfeit currency

Hi Everyone , I watching one of the local stations and they were talking about counterfeit notes in circulation , i was shocked to learn that how good the fake currency are and not easy to detect ...normally i used to check for the lion and the the eyes in specific then would know the currency is genuine or not ...apparently the fake notes have that too.. so any one with ideas on how to check if a note is fake or genuine will be really helpful thanks --