CMS - CISUC - Universidade de Coimbra

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(c) Carlos Bento et al., RFID Technologies

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CMS - CISUC - Universidade de Coimbra

Carlos Lisboa Bento

Francisco Câmara Pereira

Pedro Fonseca

RFID Technologies Avances Tecnológicos para la Sociedad Digital UEM April 14-18

Contents

o

RFID: An Introduction

o

Security Issues

o

Privacy Issues

o

Steps for Development of a Medium Project

o

Applications

o

A Practical Example

o

Our tags

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(c) Carlos Bento et al., RFID Technologies

RFID: An Introduction

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Radio Frequency IDentification

Dedicated Short Range Communication (DSRC)

Designates a range of technologies that use radio waves to automatically

identify goods or people

An RFID system consists of two sides:

Reader

Antenna

Transceiver

Processing device

Tag

Radio Frequency circuitry

Information to be transmitted

Reader

Antenna

Transceiver

Processing device

Tag

Radio Frequency circuitry

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RFID: An Introduction

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Passive Tag

Antenna signal

feeds power to

the tag

It then transmits its information to the reader

Active Tag

The tag has its own on-board power supply

It becomes a relatively self-sufficient unit

(own memory, sensors,...)

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RFID: An Introduction

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RFID: An Introduction

Frequency

LF

125-134KHz

13.56MHz

HF

88-108MHz

VHF

860-960MHz

UHF

1.6-30GHz

MW

Reflection

Absorption

No

Low

High

Very High

Very Very

High

Atmospheric

Interference

No

High

Low

Very Low

No

Electrical

Interference

Very High

High

Medium

Low

Very Low

Reading

Distances

< 2m

< 1m

1-100m

1-100m

1-300m

Band Wide

1-10KB/s

1-3KB/s

1-20KB/s

0.1-10MB/s

0.1-10MB/s

Pos

Low Price/

Lower obfusc

and Rd Speed

Medium Dist

Long Dist and High Rd Speed

Cons

Reading

Speed

Price Higher

than LF

Expensive Hardware

Typical

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(c) Carlos Bento et al., RFID Technologies

RFID: An Introduction

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Antennas

A - Wall/Desktop antenna

B - HF antenna

C - Portal antenna

Range shape is also an issue.

Contents

o

RFID: An Introduction

o

Security Issues

o

Privacy Issues

o

Steps for Development of a Medium Project

o

Applications

o

A Practical Example

o

Our tags

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(c) Carlos Bento et al., RFID Technologies

Security Issues

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Radio Frequency Absorber

Disable the tag from being read (e.g. involve it in an aluminum sheet)

Spoofing

Produce faking information for the reader

Inserting

Insert commands in memory areas that result into bad behaviour of the tag

Replay

Save a valid signal from the tag and produce a ghost signal

DoS

Denial of Service

Back-end

Produce attacks in the back-end of the system

Memory overflow

Change the memory size parameters in the tags to produce a memory

overflow error

Contents

o

RFID: An Introduction

o

Security Issues

o

Privacy Issues

o

Steps for Development of a Medium Project

o

Applications

o

A Practical Example

o

Our tags

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(c) Carlos Bento et al., RFID Technologies

Privacy Issues

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Destroy the tag (e.g. destroy the antenna)

Reduce tag performance (e.g. cut part of the antenna)

Create a Faraday Cage

Privacy Issues

Signal Interference

Information Encryption

Re-encryption

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(c) Carlos Bento et al., RFID Technologies

Contents

o

RFID: An Introduction

o

Security Issues

o

Privacy Issues

o

Steps for Development of a Medium Project

o

Applications

o

A Practical Example

o

Our tags

o

Programming in C#

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Development Steps

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(c) Carlos Bento et al., RFID Technologies

Contents

o

RFID: An Introduction

o

Security Issues

o

Privacy Issues

o

Steps for Development of a Medium Project

o

Applications

o

A Practical Example

o

Our tags

o

Programming in C#

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Applications

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Applications

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Applications

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(c) Carlos Bento et al., RFID Technologies

Applications

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TOUAKI (SU 2006/7)

Contents

o

RFID: An Introduction

o

Security Issues

o

Privacy Issues

o

Steps for Development of a Medium Project

o

Applications

o

A Practical Example

o

Our tags

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(c) Carlos Bento et al., RFID Technologies

A Practical Example

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SRF55V10P RFID tags

128 pages of 8 bytes each

Three first pages (0 to 2) are protected

A Practical Example

SRF55V10P RFID tags

Aproximately 1Kb available

Syscan CF-Reader E04-40D

Interface with Compact Flash interface

13.56 frequency (HF)

Range of a few centimeter

Reads one tag at a time

Simple commands

Read, write, getID, getReaderVersion

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A Practical Example

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PDA RFID reader

C#, Visual Studio CF environment

As with other interfaces (GPS, GSM, WiFi...), communication is made via

the "COM" ports

In this case, it is always Port #7

A Practical Example

Library available (in a DLL)

NetSerial.dll

using Intensecomp.RFIDCE

Class to access the reader, RFID: Comm

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(c) Carlos Bento et al., RFID Technologies

A Practical Example

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Reading an ID

Reading

reader version

String id = comm.GetTagID();

if (id != null && id.Length > 0)

MessageBox.Show(“ID:”+id);

else

{

MessageBox.Show("Etiqueta não encontrada!");

return;

}

if (comm.OpenPort())

{

string rv = comm.GetReaderVersion();

}

A Practical Example

Writing data

Hexadecimal representation

"KLMN“(ASCII) = "4B4C4D4E" (Hexa)

Each

char

(of a

string

), 8 bits, is represented by Hexadecimal symbols.

“K”=“4B”

private string StringToHexString(string source)

{

string result = string.Empty;

for (int i = 0; i < source.Length; i++)

{

int ch = source[i];

result += Convert.ToString(ch, 16);

}

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A Practical Example

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Writing data

Example: Write the “email” on pages 4 to 6

String strpage = string.Empty;

String s1 = textBox1.Text;

String s1HEX = StringToHexString(s1) + new string('0',2000-

s1.Length);

for (int i = 0; i < 124; i++)

strpage = comm.WritePage(i + 3, s1HEX.Substring(i * 16,

16), 100);

//Três páginas (4 a 6) de 8 bytes dedicadas ao email (24

bytes)

for (int i = 4; i < 7; i++)

email = email + comm.ReadPage(i , 20);

A Practical Example

Reading data

Hexadecimal representation

The converse operation

private string HexStringToString(string source)

{

string result = string.Empty;

try

{

while (source.Length > 1)

{

string sub = source.Substring(0, 2);

char ch = (char)Convert.ToInt32(sub, 16);

if ((ch != (char)30) && (ch != (char)0))

result += ch;

source = source.Substring(2, source.Length - 2);

}

}

catch

{

}

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A Practical Example

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Reading data

Reading email (pages 4 to 6)

String email = string.Empty;

//Três páginas (4 a 6) de 8 bytes dedicadas ao email

(24 bytes)

for (int i = 4; i < 7; i++)

email = email + comm.ReadPage(i , 20);

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(c) Carlos Bento et al., RFID Technologies

RFID Technologies

Figure

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