An NFC Ticketing System with a new approach of an Inverse Reader Mode Dresden, 22/11/2013 Felipe de Sousa Silva
Outline NFC Overview NFC Public Ticket System. Intention of the Inverse Reader Mode The Inverse Mode Design Validation Process Conclusion
NFC Overview What is NFC? NFC ( near field communication ) is a short-range wireless technology that enable two devices to securely exchange small amounts of data when they are placed a few centimeters apart. Applications of NFC Files transference Collect multimedia information E-payment Public transportation ticketing
Why should I use NFC? NFC vs Paper tickets Tickets stored in phones are less likely to be lost than paper tickets. Studies have repeatedly shown that people are less likely to leave home without their phones than anything else. Obtaining a ticket is much more convenient, because it can be sent electronically to the NFC-enabled phone.
Why should I use NFC? NFC vs Contactless Card An NFC-enabled phone can hold more than one ticket from more than one transport operator. Using their NFC-enabled phones, consumers can manage their cards and tickets anywhere at any time. Smart cards stored in an NFC-enabled phone are less susceptible to collision.
Why should I use NFC? NFC vs Barcode NFC ticketing is also faster. There is no need to open an application to find the 2D barcode; the phone experience is a simple tap-and-go. NFC-enabled phones are two-way devices, enabling the traveler to both send and receive information, while 2D barcodes are read-only. QR codes are not always easy to read
NFC Modes Operation Modes Reader / Write Card emulation Peer-to-peer
NFC Modes Operation Modes Reader / Write Card emulation Peer-to-peer
NFC Modes Operation Modes Reader / Write Card emulation Peer-to-peer
NFC Design The NFC chip has direct access to UICC and SAM chip. The Secure chip and UICC are used to store sensitive data like keys and personal information. Unfortunately the usage of the SE is restricted by the owner. Manufacturer MMO TSM
NFC Ticketing System
Intention of the Inverse Reader Mode Current ticketing systems use NFC enabled mobile phones in card emulation or peer-to-peer mode. Problems with card emulation mode: Owner of the secure element vs. third party service provider restricted or no access to the secure element of the mobile phone. Problems with peer-to-peer mode: Compatibility problems with different implementations (e.g. Symbian vs. Android) No access to the lower layers (APDU) on some operating systems (e.g. Windows Phone) Problems with software emulated tags: Only few implementations (e.g. RIM s Blackberry OS since version 7, Cyanogenmod
Intention of the Inverse Reader Mode New approach: Inverse Reader Mode No secure element is needed on the mobile phone The mobile phone uses only the reader/writer mode, which works on all NFC enabled phones Light-weight and well-established protocol stack (ISO/IEC 14443-4 and 7816-4) Card emulation support is needed on the reader side
The Inverse Mode Design
APDU Exchange Data For exchanging data from the smartphone to the validation terminal APDU messages are used. APDU Commands SELECT DF READ BINARY WRITE BINARY
File System StationID Stores the identification of the ticket station. TicketID Used to store the ticket information into the ticket station. TicketDate Similar to the TicketID File. Used to store the ticket date. ValidInfo The Server check the information and write into this file the result.
Validation Process NFC phone requests the station ID. The phone selects the correct ticket, send to the system and wait for a confirmation. The phone send the ticket date and wait for another confirmation. At the end the phone send a message requesting the content of the validinfo file.
Validation Process If the validation process was accomplished successfully, all file identifiers will be set to their default values.
Conclusion Alternative to the card emulation mode Avoiding the access restrictions of the secure element Until now security was not considered in detail
References http://www.smartcardalliance.org/pages/publications-nfc-frequently-askedquestions http://www.nexperts.com/nexpertise/technology/how-does-it-work/ http://www.nfc.cc/wp-content/uploads/2011/03/architecture.jpg http://supportforums.blackberry.com/t5/native-development/peer-to-peer- NFC-How-to-send-multiple-messages/td-p/2645143 http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6482448 http://nfc-workshop.org/2013/documentation/presentation_fh- OOe_InverseReaderMode.pdf
Thank You!