If you are on a ps4 and you have finished your daily contracts you can keep refreshing and earning 10 cryptokeys at a time with this method, go over to the black market and look at your current daily contract, press the PS button and head over to settings > date and time, turn off automatic time and click manual select, simply put the clock 2 days forward and click X to save, go back over to black ops 3 and you should have a black screen with the orange treyarch logo at the bottom right, now go over to black market and look at your daily contract, it should be a brand new one. Ps, you can repeat this process as many times as you want and earn as many cryptokeys as you like! ( sorry for the bad tutorial wanted to get it out quick !)