Lehrstuhl Netzarchitekturen und NetzdiensteInstitut für InformatikTechnische Universität München

NFC – Near Field Communication

HauptseminarInnovative Internettechnologien und

Mobilkommunikation

Wintersemester 09/10

Christian Lohmaier <lohmaiec@in.tum.de>

NFC – Near Field Communication 2

Overview

Was is NFC?

Comparison with other technologies

Standards

Security

Weblinks

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What is NFC? - Basics

Goal: low-range, easy, natural and secure interaction Low-range communication – up to 10 cm Same base technology as RF-ID Supports peer-to-peer communication Three operating modes

reader/writer (PCD – proximity coupling device) Peer-to-peer Card emulation (PICC – proximity inductive coupling card)

Can act as “helper” for other technologies

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What is NFC? - Basics (continued)

As mentioned very similar to RF-ID

Uses magnetic field induction 13,56 Mhz Both active/passive as well as active/active mode Combination of “(Secure) Smart Card” with RF-ID Can be used when barcodes/data-matrix codes cannot hold enough

information

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What is NFC? - Applications

PCD Timetables at the busstop Touristic information in museum/points of interest Bookmark or other info from advertizing poster Usually less than 4 Kb of data

PICC Make payments Take part in loyalty/bonus programs Access control (key card)

P2P Synchronize calendars Setup other wireless communication methods (Wi-Fi/Bluetooth)

© Rhein-Main-Verkehrsverbund GmbH

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Comparison with other technologies

Data Rates

50-100 high

Bluetooth 10 medium

50-100

10

NFC 0,1

Range (m) PowerConsumption Use Cases

Wi-Fi 11/54 Mbit/s WLAN, filtetransfer, internet connectivity

1 Mbit/s headsets and similar

Zigbee very low 20/40/250 kbit/s monitoring, embedded sensing, industrial control

Ultra-Wideband low 100-500 Mbit/s image and video transfer

low 106-424 kbit/s Payment/Ticketing, etc.

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Standards

Near Field Communication Interface and Protocol-1 (NFCIP-1) ISO/IEC 18092 ECMA 340 ETSI 102.190

Covers modulation schemes, coding, transfer speeds, frame format of the RF interface initialization schemes, data collision control during initialization

Near Field Communication Interface and Protocol-2 (NFCIP-2) ISO/IEC 21481 ECMA 352

Covers detection/selection of one of the three communication modes

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Standards – Backwards compatibility

ISO/IEC 14443 (type A and B)

Proximity Cards (distance up to 20 cm) ISO/IEC 15693

Vicinity Cards (10 cm up to 2 m)

Proprietary Standards FeliCa (Sony) MIFARE (Philips) Topaz (Innovision)

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Security considerations

Eavesdropping possible at all times Active devices up to 10 m Passive devices up to 1 m

Data corruption Easily possible, using a RFID-jammer (DoS)

Data modification Possible in general, feasability depends on

modulation used Miller with 100% Modulation (106 kbps)

only some bits can be altered Manchester with 10% Modulation (transfer

speeds > 106kbps) all bits can be altered, although probably recognized because of the signal level

Creative commons by Joe Howell

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Security considerations (continued)

Data insertion Possible when there's a big pause before real device sends its answer

Man-in-the-Middle attack Practically impossible Alice would detect Eve's attempt to block the message to Bob Eve would need to send Data to Bob, while Alice's RF-field is still active

(or when both Alice and Bob are using active mode, Alice would turn off the RF-field and receive Eve's message to Bob)

Solution to the above problems: Establish a secure channel

A plain Diffie-Hellmann key exchange protocol is enough, as Man-in-the-Middle attacks are pratically impossible

other problem: Privacy

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Weblinks

NFC-Forum http://www.nfc-forum.org

ECMA http://www.ecma-international.org/publications/

ISO http://standards.iso.org/ittf/PubliclyAvailableStandards/index.html

StoLPaN http://www.stolpan.com

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Questions

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