I have received an NFC (near field commu­ni­ca­tion) TK eHealth card. Why do I need a CAN (card access number)?

The CAN (card access number) prevents your card from being used without your authorisation. The six-digit CAN is located on the front of your eHealth card. To access your data using NFC, you first need to enter the CAN before you can access it with your PIN.