near field communication (nfc) for next generation smart phone apps

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NFC – For Next Generation Smart Phone Apps

Ashutosh TripathiTalentica Softwares

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Agenda

• What is NFC ?

• Why NFC ?

• How NFC works

• NFC & Mobiles

• Building NFC App – Android

• Security Aspects

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What is NFC ?

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• Near Field Communication

• Short Range Wireless (a few centimeters)

• Operates at frequency 13.56 MHz

• Less speed (106kbps – 414 kbps)

• Low Friction Setup

• Passive Targets

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Why NFC ?

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To Read Smart Posters

As Event Tickets

Sharing Business Card

Easy Printing

Mobile Payment

Transport Ticketing

File Sharing

ID Cards

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Enhanced Wireless experience

•Instant Bluetooth Pairing

•Instant Wi-Fi Configuration

Wireless Nirvana

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Google Wallet

• Stores virtual version of your existing cards

• Tap and pay

• Receive loyalty cards, recipiets

• Secure

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Its just the beginning….

• Peer 2 Peer Payment

• Electronic Keys

• Social Networking

• Smart Mobility

• Entertainment

• Secure PC Login

• More…..

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How NFC Works

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Communication Modes

Active• Both Initiator and target is powered devices

Passive• Target device may draw its operating power from the initiator-

provided electromagnetic field

Initiator

Initiate Communication by generating RF field

Active Device Active/Passive Device

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Operating modes

Reader/Writer

Peer to Peer

Card Emulation

Card Emulation Mode

Peer 2 Peer Mode

Reader/WriterMode

Application

RTD&

NDEFLLCP

NFC Forum protocol bindingsCard emulation

Smart Card capability for

mobile devices Tag types 1-4

RF layer ISO 18092 + ISO14443 Type A,B + Felica

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NDEF – NFC Data Exchange Format

• Message Encapsulation format to exchange information between NFC devices/tags

• Lightweight, binary

• Supports URI,MIME or NFC specific types

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NDEF Record

Flags

• MB,ME,CF,SR

Type Name Format

Type

ID

Payload

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Type Name Format Value

Empty 0x00

NFC Forum Well Known Type 0x01

MIME Type 0x02

Absolute URI 0x03

NFC Forum External Type 0x04

Unknown 0x05

Unchanged 0x06

Reserved 0x07

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NFC & Mobiles

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Already in Market..

• Google Nexus S (1st NFC Android Phone)

• Samsung Galaxy SII (android)

• Nokia C7

• Blackberry Bold 9900 and 9930

• Nokia 6131 (1st NFC Phone now out of market)

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Upcoming & Rumored

• iPhone 5 (rumored)

• Nokia N9,N5

• Multiple Android OS 2.3.3 based phones

• LG Optimus NET

• Samsung BADA OS based phones

• Many more…

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Future Market

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What we have learned so far..

• NFC is short range wireless communication

• Works with both active/passive targets

• Can read/write passive tags

• Easy sharing ,printing, pairing and transaction

• Data transaction is done in NDEF format

• Great future

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Building NFC App - Android

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What we can do with Android (for now)

• Reading Tags

• Writing Tags

• Peer 2 Peer Communication (limited)

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How we start

• Essential

• Set required permission in Manifest

• Add required intent filers in Manifest

• Handle intent in main Activity to read data

• Working approach

• Intent Dispatch : identify appropriate application

• Foreground Dispatch : intercept in your application

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Defining Intent Filter

<intent-filter>  <action android:name="android.nfc.action.NDEF_DISCOVERED"/>  <data android:mimeType="mime/type" />

</intent-filter>

<intent-filter>  <action android:name="android.nfc.action.TECH_DISCOVERED"/>  <meta-data android:name="android.nfc.action.TECH_DISCOVERED"                android:resource="@xml/nfc_tech_filter.xml" />

</intent-filter>

<intent-filter>  <action android:name="android.nfc.action.TAG_DISCOVERED"/>

</intent-filter>

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Filtering supported TAG

<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">    <tech-list>        <tech>android.nfc.tech.IsoDep</tech>        <tech>android.nfc.tech.NfcA</tech>                <tech>android.nfc.tech.NfcB</tech>        <tech>android.nfc.tech.NfcF</tech>        <tech>android.nfc.tech.NfcV</tech>        <tech>android.nfc.tech.Ndef</tech>        <tech>android.nfc.tech.NdefFormatable</tech>        <tech>android.nfc.tech.MifareClassic</tech>        <tech>android.nfc.tech.MifareUltralight</tech>    </tech-list></resources>

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Your Manifest – Putting all together

<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.android.nfc">

<uses-permission android:name="android.permission.NFC" />

<uses-sdk android:minSdkVersion="9" />

<uses-feature android:name="android.hardware.nfc" android:required="true" />

<application android:icon="@drawable/icon" android:label="@string/app_name">

<activity android:name="TagViewer" >

<intent-filter>

<action android:name="android.nfc.action.TAG_DISCOVERED"/>

<category android:name="android.intent.category.DEFAULT"/>

</intent-filter>

</activity>

</application>

</manifest>

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Handle Intent : MainActivity.java

NdefMessage[] getNdefMessages(Intent intent) {

NdefMessage msg = null;

if (NfcAdapter.ACTION_TAG_DISCOVERED.equals(intent.getAction()))

{ msgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES)[0];

if (msg == null) {

byte[] empty = new byte[] {};

NdefRecord record = new NdefRecord(NdefRecord.TNF_UNKNOWN, empty, empty, empty);

msg = new NdefMessage(new NdefRecord[] {record});

} } else {

// Your logic }

return msg;

}

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

NdefMessage msg = getNdefMessage(getIntent());

// process msg

}

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Writing data:

String text;

NdefRecord textRecord = new NdefRecord(NdefRecord.TNF_MIME_MEDIA,

"text/plain".getBytes(), text.getBytes());

NdefMessage textMessage = new NdefMessage(new NdefRecord[]{textRecord});

Tag tag = getIntent().getExtra(NfcAdapter.EXTRA_TAG);

Ndef ndef = Ndef.get(tag);

ndef.writeNdefMessage(textMessage);

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Security Aspects

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1. Eavesdropping

2. Data Modifications

3. Data Insertion

4. Man-in-the-middle Attack

5. Lost Property

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Thanks