Credit chip
A credit chip was a device used for the transfer of money in the 21st century. 

In 2024, Christopher Brynner asked a time traveling Jadzia Dax whether she had been "jacked" of her credit chips and identification card. 

Later, Biddle Coleridge thought it might be a good idea to trade hostages for amnesty and credit chips. ()

See also 
Credit
Credit card
Federation credit

de:Creditchip

Earth currencies