Data-Card
Special cards with high data capacity. Akin to pen-drives of the twenty-first century, having half the size of a credit card of the same era.
Two type of Data-Cards are in use, one for general data which is encrypted with authenticity-algorithms to trace the owner and/or issuer back, the other is highly encrypted and is used exclusively for monetary transactions. The latter is similar to the twenty-first century prepaid credit cards.