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A Technical Seminar ReportOn
“NFC TECHNOLOGY”
Submitted in partial fulfillment of the requirements for the award of the degree of
BACHELOR OF TECHNOLOGYin
ELECTRONICS & COMMUNICATION ENGINEERINGfrom
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD
by
M.SAIPRASAD (10TK1A0462)
Under the esteemed guidance of
Mr. CH. RAMESH BABU M. TechAsst. Professor
E.C.E
DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING
SVS INSTITUTE OF TECHNOLOGY (Approved by AICTE, New Delhi & Affiliated to JNTU, Hyderabad & ISO 9001:2008 certified)
BHEEMARAM(V), HASANPARHY(M),WARANGAL (Dt). A.P. India -506015Ph: 0870-2453900, 6560833
www.svsit.ac.in (2010-2014)
SVS INSTITUTE OF TECHNOLOGY
(Approved by AICTE, New Delhi & Affiliated to JNTU, Hyderabad & ISO 9001:2008 certified)BHEEMARAM(V), HASANPARHY(M),WARANGAL (Dt). A.P. India -506015
1. INTRODUCTION
Near Field Communication is a new short-range wireless connectivity
technology that evolved from a combination of existing contactless identification and
interconnection technologies. It was jointly developed by Sony and NXP
Semiconductors (formerly Philip).
NFC operates in a frequency range centered at 13.56 MHz and offers a data
transmission rate of up to 424 kbit/s within a distance of approximately 10cms. NFC is
backward compatible with the Smart Card infrastructure based on ISO/IEC
(International Organization for Standardization/ International Electrotechnical
Commission) 14443 A and ISO/IEC 14443 B as well as with the Sony FeliCa
card. For the exchange of information between two NFC devices, a new protocol was
developed which is defined in the standards ECMA (European Computer Manufacturers
Association) 340 and ISO/IEC 18092 . The NFC Forum was founded in the year 2004
by NXP, Sony and Nokia to work towards the development and deployment of NFC.
The NFC forum develops
Specifications which ensure interoperability of NFC units and services.
Fig. 1.1 Evolution of NFC technologies
Currently, devices such as Nexus S, Galaxy Nexus, Samsung Galaxy Note, Sony Xperia
ZR, Nokia 6131 NFC etc. provide NFC facility to its users. Some applications of NFC are
Google Wallet (US), A Little World (India) for mobile payments, China Unicom for
mobile transport ticketing (China) etc.
1.2 Comparison with Existing Technologies
Table 1.1 shows the comparison of various existing wireless technologies with NFC and
its benefits over the others.
Table 1.1 Comparison of NFC with various existing technologies.
Sr.
No
Concept NFC Bluetooth
(IEEE
802.15.1)
WiFi
(IEEE
802.11)
RFID Zigbee (IEEE
802.1.5.4)
1 Range <0.1m
(generally
10cm)
10m 100-150m 3m 30-100m
2 Throughput 106, 212,
424kbps
721kbps 6Mbps Varies 100Vkbps
3 Operating
Frequency
13.56Mhz ISM band
2.4Ghz to
2.485Ghz
2.4Ghz Varies 862Mhz,
915Mhz,
2.4Ghz
4 Latency <0.1 sec 6 sec 1.5ms < 1 sec 20 ms
5 Cost Low Moderate High Low Moderate
6 Power
Consumption
Moderate
to low
Low High Low Moderate
7 Security Fairly
secure
PIN 64bit,
128bit
(Less secure
than WiFi)
More
secure
than
bluetooth
Secure 128-bit AES
Hence, NFC has good speed of operation for close proximity. It is suitable for crowded
areas. It uses ISM band of frequency which is available worldwide. NFC is affordable,
has good throughput and low latency. Since transactions are done at a small range at
which signals are not much susceptible to interception, NFC is highly secure. Thus, NFC
can be a very beneficial wireless mode of communication for short ranges and can be
used for fast transactions eg. Money transfer etc.
NFC occurs between two NFC devices in a close proximity range (within a few
centimeters). These two NFC devices can operate in several modes as described in
chapter 2.
2. OPERATION OF NFC
There are two different roles that a device can play in NFC which can be illustrated
as a “request and reply” concept as shown in Fig. 1.2. The initiator (or polling device)
sends a request message to a target and the target (or listening device) replies by sending
a message back to the initiator. In this case the role of the initiator is to start the
communication. The role of the target is to respond to the requests coming from the
initiator .
Fig. 2.0 Initiator (Polling device) and Target (Listening device) device
2.1 Basics of Data Transmission with NFC
NFC is based on inductive coupling, where loosely coupled inductive circuits
share power and data over a distance of a few centimeters . Similar to the transformer
principle, the magnetic near-field of two conductor coils is used to couple the polling
device (initiator) and listening device (target) as shown in Fig. 1.2. The operating
frequency is 13.56 MHz, and a bit-rate of 106 kbit/s (also 212 kbit/s and 424 kbit/s)
is used. Modulation schemes are amplitude on/off keying (OOK) with different
modulation depth (100 % or 10 %) and BPSK. This is summarized in Table 1.2
Table 2.1 Modulation and coding schemes based on device type and data rate.
Speed Active Device Passive Device
106 kbps Modified Miller, 100% ASK Manchester, 10% ASK
212 kbps Manchester, 10% ASK Manchester, 10% ASK
424 kbps Manchester, 10% ASK Manchester, 10% ASK
Power Transmission and Data Transmission from a Polling Device
For transmission to a passive system such as an NFC phone in passive card
emulation mode (described in chapter 2), the passive system uses the 13.56 MHz
carrier signal of the polling device as energy source. Modulation scheme of the polling
device is ASK. For NFC peer-to-peer mode, both directions are modulated and coded like
a polling device. However less power is necessary because both NFC devices use their
own power supply and the carrier signal is switched off after end of transmission.
Data Transmission from a Listening Device
Due to the coupling of the coils of initiator and target, a passive target also affects
the active initiator. A variation in the impedance of the target causes amplitude or phase
changes to the antenna voltage of the initiator, detected by it. This technique is called
load modulation. Load modulation is carried out in target mode using an auxiliary
carrier at 848 kHz which is modulated by the baseband and varies the impedance of the
target device. Fig.1.3 shows the spectrum with load modulation. The modulation scheme
Is ASK (ISO/IEC 14443 A) or BPSK (ISO/IEC 14443 B) .
Modulation Schemes used by NFC are ASK (100% and 10% modulation depths)
and BPSK. Also, NFC uses Modified Miller and Manchester Coding schemes
depending upon the type of communication used, i.e., Type A (normal) or Type B
(banking/short range).
Fig. 2.1 Modulation Spectra showing Load modulation
Time Domain Frequ enc y Dom ain
Fig 2.2 Visualization of load modulation
Fig. 1.4 visualizes load modulation for ASK modulation with Manchester Coding.
2.2 NFC OPERATING MODES
In the previous chapter we discussed how basic data transmission takes place in
NFC. In this chapter we discuss the classification of devices used in NFC. Building
upon the basics learned in chapter 1, we move towards the study of various operating
modes of NFC devices and discuss their usage models.
2.2.1 Mobile Interaction Techniques
When mobile devices are used to interact with smart objects in the
environment, additional components are required where when a user interacts with a smart
object using an interaction technique. Fig. 2.1 shows the available interaction techniques
that the mobile devices use, which are called mobile interaction techniques, are
touching, pointing, and scanning. The NFC technology interaction technique is touch
based.
Fig 2.2.1 Mobile Interaction Techniques
2.2.2 Active vs. passive devices
An active device is one that is powered by some power source, e.g. battery, so that
it generates its own electromagnetic field. On the other hand, a passive device is one that
does not have any integrated power source. In NFC, the energy to the passive device is
supplied by the active device. To summarize, an active device powers the passive device by
creating the electromagnetic field.
2.2.3 INITIATOR vs. TARGET DEVICES
NFC always occurs between two parties, so that one party is called the initiator, and
the other party is called the target. The initiator is the one that initiates the
communication; the target responds to the request that is made by the initiator.
An initiator always needs to be an active device, because it requires a power source
to initiate the communication. The target, on the other hand, may be either an active or a
passive device. If the target is an active device, then it uses its own power source to
respond; if it is a passive device, it uses the energy created by the electromagnetic field
which is generated by the initiator that is an active device. Table 2.1 shows the summary of
the NFC devices.
Table 2.2.3 Summary of NFC devices.
Devices Initiator Target
Active Yes Yes
Passive No Yes
Now, we move towards the discussion of various operating modes of NFC. The three existing operating modes are the reader/writer, peer-to-peer and card emulation modes. The reader/writer mode enables NFC enabled mobile devices to exchange data with NFC Forum mandated NFC tags. The peer-to-peer mode enables two NFC enabled mobile devices to exchange data with each other. In the card emulation mode, the user interacts with an NFC reader in order to use her mobile phone as a smart card such as a credit card. Each operating mode has different use case scenarios and each provides various underlying benefits to users.
2.3 Reader/Writer Mode
In reader/writer operating mode, an active NFC enabled mobile phone
initiates the wireless communication, and can read and alter data stored in NFC tags. In
this operating mode, an NFC enabled mobile phone is capable of reading NFC Forum
mandated tag types, such as NFC smart poster tags. This enables the mobile user to retrieve
the data stored in the tag and take appropriate actions afterwards. This is shown in Fig. 2.3
Fig. 2.3 Reader/Writer Mode
The reader/writer mode’s RF interface is compliant with ISO/IEC 14443 Type A and Type B. NFC Forum has standardized tag types, operation of tag types and data exchange format between components. The reader/writer operating mode usually does not need a secure area. The process consists of only reading data stored inside the passive tag and writing data to the passive tag. The protocol stack architecture of the reader/writer operating mode, the (NFC Data Exchange Format) NDEF and record types are explained in the following sections.
PROTOCOL STACK ARCHITECTURE OF READER/WRITER MODE
fig. 2.3.1 shows the protocol stack architecture of reader/writer mode.
2.4 Peers-to-Peer Mode
In peer-to-peer mode, two NFC enabled mobile phones establish a
bidirectional connection to exchange information as depicted in Fig. 2.6. They can
exchange virtual business cards, digital photos, and any other kind of data. Peer-to-peer
operating mode’s RF communication interface is standardized by ISO/IEC 18092 as
NFCIP-1.
Due to the low transfer speed of NFC if large amounts of data need to be sent,
peer to peer mode can be used to create a secondary high speed connection (handover) like
Bluetooth or Wi-Fi.
Fig. 2.4 Peer-to-peer mode
This mode has 2 standardized options: NFCIP-1 and LLCP. NFCIP-1 takes
advantage of the initiator-target paradigm in which the initiator and the target devices are
defined prior to starting the communication. However, the devices are identical in LLCP
communication. After the initial handshake, the decision is made by the application that is
running in the application layer.
On account of the embedded power to mobile phones, both devices are in active
mode during the communication in peer-to-peer mode. Data are sent over a bi-directional
half duplex channel. Meaning that when one device is transmitting, the other one has to
listen and should start to transmit data after the first one finishes. The maximum possible
data rate in this mode is 424 kbps.
PROTOCOL STACK ARCHITECTURE OF PEER-TO-PEER MODE
Fig. 2.4 shows the protocol stack architecture of peer-to-peer mode.
Fig. 2.4 Protocol Stack of peer-to-peer operating mode
2.5 Card Emulation Mode
In card emulation mode, the NFC enabled mobile phone acts as a contactless
smartcard. Either an NFC enabled mobile phone emulates an ISO 14443 smart card or a
smart card chip integrated in a mobile phone is connected to the antenna of the NFC
module. As the user touches her mobile phone to an NFC reader, the NFC reader initiates
the communication. The communication architecture of this mode is illustrated in Fig.
2.5.
In this mode, the NFC device appears to an external reader much the same as a
traditional contactless smart card. This enables contactless payments and ticketing by
NFC devices without changing the existing infrastructure. Mobile devices can even store
multiple contactless smart card applications in the smart card. Examples of emulated
contactless smart cards are credit card, debit card, and loyalty card
.
Fig. 2.5 Card Emulation mode
PROTOCOL STACK ARCHITECTURE OF CARD EMULATION MODE
Fig. 2.5.1 Protocol stack of Card Emulation Mode
3. NFC SECURITY
Security is the degree of protection against an intentional or accidental misuse or
action. So far we have discussed the working of NFC. This chapter gives analysis of
security with respect to NFC. It lists the threats, which are applicable to NFC, and
describes solutions to protect against these threats. All of this is given in the context of
currently available NFC hardware, NFC applications and possible future developments of
NFC.
3.1 Threats and Solutions
A possible danger that has the potential to cause an unfair benefit to the
unauthorized people or to cause harm by exploiting vulnerability is called a threat.
Threats may be either intentional or unintentional. The threats involved are eavesdropping,
data corruption, data modification, data insertion, man-in-the-middle attack etc. NFC by
itself cannot protect against eavesdropping. It is important to note that data transmitted in
passive mode is significantly harder to be eavesdropped on.
NFC devices can counter data corruption because they can check the RF field,
while they are transmitting data. If an NFC device does this, it will be able to detect the
attack. The power which is needed to corrupt the data is significantly bigger, than the
power which can be detected by the NFC device. Thus, every such attack should be
detectable.
Protection against data modification can be achieved in various ways. By using
106k Baud in active mode it gets impossible for an attacker to modify all the data
transmitted via the RF link. This means that for both directions active mode would be
needed to protect against data modification. But this has the major drawback, that this mode
is most vulnerable to eavesdropping. Also, the protection against modification is not
perfect, as even at 106k Baud some bits can be modified. NFC devices can check the RF
field while sending. This means the sending device could continuously check for such an
attack and could stop the data transmission when an attack is detected . Data insertion
attack can be avoided by the answering device by answering without delay.
3.2 Standardised NFC Security Protocols
Security protocols of NFCIP-1 are standardized in ECMA 385 as NFC-SEC (NFC
Security) and ECMA 386 as NFC-SEC-01 .These security protocols are used in peer- to-
peer operating mode.
NFC-SEC provides security standard for peer-to-peer NFC communication.
Protocols that are included within NFC-SEC are defined to be used on top of NFCIP-1
protocol .
NFC-SEC-01 is standardized in ECMA 386 which specifies cryptographic
mechanisms for key agreement, data encryption and integrity .
NFC-SEC describes two different protocols as summarised in Table 3.1
Table 3.2 Summary of security services provided by various protocols.
Protocol Security Services
NFC-SEC Eavesdropping, Data modification
NFC-SEC-01 -Diffie-Hellman key exchange (192 bit)
-Key derivation and confirmation (AES 128 bit)
-Data encryption (AES 128 bit)
-Data integrity (AES 128 bit)
NFC by itself cannot provide protection against eavesdropping or data
modifications. The only solution to achieve this is the establishment of a secure
channel over NFC using NFC-SEC protocols. This can be done very easily, because
the NFC link is not susceptible to the Man-in-the-Middle attack. This resistance against
Man-in-the-Middle attacks makes NFC an ideal method for secure pairing of devices.
4. NFC APPLICATIONS
This chapter is about developing NFC applications for mobile phones. There are
various NFC development platforms and languages. Example, for mobile phones with
Android operating system, Android SDK is used for NFC development .
NFC is used for a wide range of applications which can be divided into three
categories as shown in Fig. 4.1:
Fig. 4.1 Range of applications of NFC
The several of applications of NFC can be shown in Fig. 4.2.
Fig. 4.2 Applications of NFC
5. CONCLUSION
Near field communication can be extremely beneficial in the modern era of
technology. NFC is an extremely simple and convenient technology because the data
exchange can be done by just bringing two NFC enabled devices together. It is
interactive and secure which does not require any special software to run on. The
underlying standards of NFC follow universally implemented ISO, ECMA and ETSI
standards. It also does not require any manual configuration or settings which make it
easier for consumers.
Thus, NFC is a new technology and like other technologies it is hard to make it
mainstream as of now because of technological limitations. But it’s fast growing and it
will be successful once the strict security measures are set in place.
5. REFERENCES
[1] Vedat Coskun, Kerem Ok and Busra Ordenizci, “Near Field Communication from
Theory to Practice”, 1st Edition. New York: Wiley, 2012.
[2] NFC Forum, Analog, Technical Specification, Version 1.0, July 2012.
[3] M. Csapodi, A. Nagy, “New applications for NFC devices”, Proc. of 16th IST
Mobile and Wireless Communications, Budapest, Hungary, IEEE, 2007, pp. 245-
249.
[4] ECMA 340: Near Field Communication Interface and Protocol (NFCIP-1), 3rd
Edition, June 2013.
[5] ECMA 352: Near Field Communication Interface and Protocol (NFCIP-2), 3rd
Edition, June 2013.
[6] Rukzio E., Callaghan V., Leichtenstern K., and Schmidt A. (2006), “An
Experimental Comparison of Physical Mobile Interaction Techniques: Touching,
Pointing and Scanning”, Proc. of Eighth International Conference on Ubiquitous
Computing, CA, USA, 17–21 September 2006, pp. 7–104.
[7] NFC Forum, NFC NFC Data Exchange Format (NDEF), Technical Specification,
Version1.0, July 2006.
[8] NFC Forum, NFC NFC Data Exchange Format (NDEF), Technical Specification,
Version1.0, July 2006.
[9] NFC Forum, Logical Link Control Protocol, Technical Specification, Version 1.0,
December 2009.
[10] Tuikka T. and Isomursu M., “Touch the Future with a Smart Touch”, VTT
Tiedotteita – Research Notes 2492, Espoo, Finland, 2009.
[11] B. Ozdenizci, M. N. Aydin, V. Coskun, K. Ok, “NFC Research Framework: A
Literature Review and Future Research Directions”, Proc. 14th IBIMA
International Business Information Management Conf., Istanbul, TURKEY, 2010,
pp. 2672-2685.
[12] Vedat Coskun, Kerem Ok and Busra Ordenizci, “Current Benefits and Future
Directions of NFC Services”, Proc. of 2010 International Conference on
Education and Management Technology (ICEMT), Cairo, Egypt, 2–4 November
2010, pp. 334–338.
[13] E. Haselsteiner, K. Breitfuß, “Security in Near Field Communication (NFC)”, in
Workshop on RFID Security, 2006.
[14] ECMA 386: NFC-SEC-01: NFC-SEC Cryptographic Standard using ECDH and
AES, June 2010.
[15] ECMA 385: NFC-SEC: NFCIP-1 Security Services and Protocol, June 2010.
[16] Franssila H., “User Experiences and Acceptance Scenarios of NFC Applications
in Security Service Field Work”, Proc. of the 2010 Second International
Workshop on Near Field Communication, Monaco, 20–22 April 2010, pp. 39
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