Developed for the banking sector in 1994, MIFARE has been used in transit systems for many years. Using 13.56 MHz as the carrier frequency, this read/write technology is extremely versatile, allowing the same card to be used in a range of applications, including access control.
Readers can be supplied to read the token Chip Serial Number (CSN) or for increased security, the reader can read information from a locked cell (termed as a Sector) on the card. To access the sector the reader must first unlock it using a special key.