Gaming machines connected to a network each have a smart card reader and an internal memory for receiving electronic tokens downloaded from the smart cards. In a secure room of a casino, there are a number of card readers containing smart cards having an appropriate memory size. These external card readers are connected to the various gaming machines via the network to provide secure financial transactions over the network. Whenever the electronic token balance of a gaming machine's internal memory exceeds a configurable upper limit, the balance is automatically reduced to a default level by the gaming machine transferring the excess money to an idle external smart card. Whenever the electronic token balance of a gaming machine's internal memory falls below a configurable lower limit, the balance is automatically increased to a default level by the gaming machine transferring the money from an idle external smart card.