Crypto keys... love them/hate them.... but I wonder if this would work to get some *note- this may violate our CoC guidelines on glitching... but it's only affecting the black market portion of the game... not the actual gameplay so it's a little bit in the grey area....
I found this for glitching cryptokeys... (this could be patched by now for all I know)
1. Join any multiplayer gamemode
2. Press start and either Y or TRIANGLE and join a friends multiplayer game or a recent players multiplayer match (press SQUARE or X to do that)
3. You will then get a black screen with a trey arch logo in the bottom right corner (which means you have done it right so far!)
4. Next you will then be backed out into a multiplayer lobby, then it will back you out to the multiplayer menu
5. VERY QUICKLY go to the black market and burn your duplicate items from supply drops
6. The duplicates should burn for a while (couple mins or less) giving you 50 Cryptokeys to 300 per time.