A serious problem with common Mifare readers, including ELID ER928 Mifare reader, is that it reads UID number (Unique Identifier number) which is the production serial number. This number is not protected and can be read by any Mifare reader. Furthermore, there are Mifare cards (known as “magic cards”) where the UID number can be changed readily by user using a low-cost Writer. Therefore, it is simple to clone a Mifare card, such that it has same UID number as another card.

ER958 Mifare SecurePlus systems do not use UID number as card ID. Instead, the card ID is written separately in a protected sector of the Mifare card, and requires knowledge of secret keys to gain access to read the content of the card. Cloning Mifare Secure Plus card is as difficult as cloning cards such as “Touch n Go” cards used in highway tolls.

All SecurePlus cards are encoded and supplied by ELID. A customer can buy standard ELID SecurePlus cards, or he can choose to have the Secure Plus cards encoded with a unique customer code, so that no other readers can read his card.