New use cases for NFC (Near Field Communication), based on pairing with WiFi and Bluetooth, will be opened up by the first specification to support full two-way communication between smartphones and IoT devices.
The venerable NFC protocol, first standardized by ISO/IEC in 2003, has already been exploited to the hilt for direct communication at distances up to four centimeters for smart payment and ticketing applications, as well as machine-readable documents including passports. But this great strength of being confined in distance also lends itself to a range of pairing applications where security is still required, but alongside the ability to transfer far larger amounts of data at distance.
The NFC component can be used to establish temporary communications for a session, with security enforced by the fact the data transfer can only take place after the user has intentionally paired the device by coming into close proximity. This physical aspect of security is also enhanced by the fact tampering or snooping of data is impossible beyond that 4cm limit.
The new bidirectional capability – without need for prior establishment of a P2P (peer-to-peer) connection via the Logical Link Control Protocol (LLCP) – also opens the door to IoT applications where smartphones are used to configure or control devices. Such devices could include digital cameras, home environmental control or lighting, or even individual radiator valves. They could also include video streaming devices, with the NFC encounter being used for authentication when the user is away from home, say wanting to view subscribed content in a hotel room.
Another use case already being worked on is the mobile secure document, such as an identity card, driving license, passport or visa. We have had chips embedded in passports for machine-readability some years, but the next logical step is to enable the document itself to be transferred to a handset.
This is not happening yet, although American Airlines has taken a step in that direction by introducing check-in using the airline’s app to scan the passport’s chip for verification of details via NFC. This allows passengers to go straight to the departure gate for international flights without having passports rechecked by a customer service agent.
But this still requires a physical passport and does not take advantage of the new bidirectional capability. However, that capability is integral to the new standard ISO/IEC 18013-5.2, specifically for driving licences on mobile devices. Applications of that come in two categories, firstly those that simply avoid need for a physical licence, such as police roadside checks where previously the licence might have been presented as proof the driver was qualified.
More interesting are the unattended use cases where the licence enables transactions that perhaps are dependent on age, or some other aspect of the user that can be verified. This might include purchase of alcohol, cigarettes, or pharmaceuticals from a vending machine. It could also include access control to websites or online services on the basis of age or other factors.
There are in fact two key related announcements from the NFC Forum, the global standards body for the technology. Firstly, it has approved and adopted the Tag NFC Data Exchange Format Exchange Protocol Specification (TNEP), and secondly, there is an updated version of the Connection Handover Technical Specification (CH 1.5).
TNEP defines bidirectional exchange of data between an NFC-enabled phone and an IoT device implementing tag and reader functionality. When combined with the CH 1.5, TNEP enables handover between NFC and either Bluetooth or WiFi by using the reader/writer mode, irrespective of the smartphone operating system. The term ‘tag’ simply refers to an NFC chip embedded in components such as smart payment cards without batteries, deriving power when close to their docking station or an active IoT device by electromagnetic induction.
TNEP is based on the standard procedure to read and write to an NFC Forum tag, so that all NFC-enabled smartphones are in principle capable of supporting it via an app. These apps are able to establish a bidirectional NFC communication link to IoT devices without need to implement the LLCP for P2P.
Bidirectional communication with IoT devices means NFC-enabled smartphones can read the actual state from the IoT device and can change its configuration through write operations. One of the main benefits is that the proximity-based security of NFC can allow applications involving reconfiguration of systems such as surveillance cameras that would previously have been considered too risky because of the potential for tampering or unauthorized access.
Of course there are still lingering security issues associated with the NFC protocol itself, around users’ credentials and encryption, but these are being addressed by ensuring that sensitive data on user devices is stored in a trusted environment.