How can I identify if I have CC or fakes?

"Supposedly" they came direct from Cuba. My buddy goes down to the Carribean 2-3 times a year and has done so for 20+ years (hotel business) and has a guy down there that he has been buying from that "supposedly" brings them over from Cuba himself. Hes been getting 2-3 boxes a year (same thing every time) from same guy for over 20 years but who knows cause when money is involved honesty has a way of being absent. This is pretty fun though trying to play super slueth!