Do I need a fast Internet connection? How much data does Kryptex consume?
Speed is not that important as its quality and stability. If there are any lags, cuts or other problems, that would lower your profits.
It is best to have your PC connected to your hotspot using a cable instead of WIFI. Though, if there is no possibility to avoid wireless connection, make sure it is strong and stable enough.
As of data, Kryptex meters around 200-300 Mb monthly.