Abstract: A smart card—host system that operates without the intermediation of a smart card reader. The smart card—host system comprises a host, which has a USB interface, and a portable device, which provides smart card function(s). The portable device has a smart card chip for performing the smart card function(s); a USB interface for connecting the portable device with the host via USB protocol; and a microprocessor for controlling the transfer of data between the USB interface and the smart card chip, for converting data from a USB format to the format of the smart card chip and for converting data from the format of the smart card chip to a USB format.