2006.10 ShangHai

Chaotic Encryption Based Information

Security of RFID System

Xin Ding Nanjing University of Posts and Telecommunications

2006.10 ShangHai XINDING,NJUPT

Introduction

RFID technology (Radio Frequency Identification) :

A means of automatically identifying a unique object by using a radio frequency transmission.

2006.10 ShangHai XINDING,NJUPT

RFID system block diagram

Backend computer

Control unit

Transceiver

TA

G

Data

Timing

Power

Coupling element (Coil, Antenna)

Reader

2006.10 ShangHai XINDING,NJUPT

Threats and Attacks against RFID system

Phyllis

Mallory

Eve

Tracy

Denise

Threats & Attacks again

RFID system

In the paper”Security and Privacy in Radio-Frequency Identification Devices” written by Stephen August Weis from http://rfidioumal.com, five kinds of attack behavior are summarized：

GOTO

2006.10 ShangHai XINDING,NJUPT

The strongest attacker. Phyllis is assumed to be able to physically obtain tags and conduct sophisticated attacks in a lab setting, can’t carry out attacks in public or on a widespread scale.

BACK

Phyllis

2006.10 ShangHai XINDING,NJUPT

Mallory

Mallory does not have physical tag access,but may actively participate in protocols or construct her own counterfeit tags.Mallory may initiate queries to tags or respond to reader queries at will.

BACK

2006.10 ShangHai XINDING,NJUPT

Eve plays a passive role.She cannot actively take part in protocols and is limited to eavesdropping.

BACK

Eve

2006.10 ShangHai XINDING,NJUPT

Tracy

Tracy is weaker than Eve.She cannot read the contents of messages,but still may detect their presence. Tracy may conduct attacks against “Location Privacy”

BACK

2006.10 ShangHai XINDING,NJUPT

Denise is the weakest behavior,Denise is limited to disrupting broadcasts,blocking messages or any other denial of service attacks.

BACK

Denise

2006.10 ShangHai XINDING,NJUPT

PresentPresentNo overall security mechanism has been proposed

ReasonReasonThe RFID system is designed to be fully open, the RFID IC itself and the communication process between reader and tag are easily attacked.

ExampleExampleRFDump: Anyone who installs a reader in his laptop can get the data in passive tags within 3 feet area by using RFDump SW.(The Black Hat 2004 conference , Las Vegas USA)

Why is the RFID information vulnerable to attacks?

2006.10 ShangHai XINDING,NJUPT

A new approach to information security of RFID system

In the new scheme proposed, the information of each RFID tag is encrypted with :

Unique corresponding Discrete Chaotic Sequence.

2006.10 ShangHai XINDING,NJUPT

What is chaos or chaotic system ?

Chaotic system :

A deterministic, nonlinear, dynamical system displaying sensitive dependence on initial conditions and having evolution through phase space that appears to be quite random.

2006.10 ShangHai XINDING,NJUPT

Properties of chaotic system

initially nearby points of the system can evolve very quickly into great different trajectories

The property is popularly known as the “butterfly effect" As a result of the sensitivity, the behavior of chaotic systems

appears to be random, exhibiting an exponential error dispersion

Being topologically transitive Having a dense collection of points with periodic orbitsBeing sensitive to the initial condition of the system

2006.10 ShangHai XINDING,NJUPT

Logistic Map

[ ] [ ]1,1,2,0,1 2

1 −∈∈−=+ xuuxx kk

When the map is exhibiting the chaotic behavior with positive Lyapunov exponent,having at least one positive Lyapunov exponent is the most important characteristic of chaotic system. the map represents a repeated folding and stretching of the phase space on which it is defined.

,241.1 <<u

2006.10 ShangHai XINDING,NJUPT

The Advantages of DCS

- Eac h DCS is no n pe rio d ic1

-DCS s a re unc o rre la te d

2

3

4 The mo re da ta the be tte r pe rfo rmanc e DCSis

Ps e udo random is be tte r than M and Go lds e que nc e

2006.10 ShangHai XINDING,NJUPT

Backend computer

Control unit

Transceiver

TA

G

Data

Timing

Power

Coupling element (Coil, Antenna)

Reader

DCSG

+

New diagram of RFID system

2006.10 ShangHai XINDING,NJUPT

Backend computer

Control unit

Transceiver

TA

G

Data

Timing

Power

Coupling element (Coil, Antenna)

Reader

RFID system block diagram

2006.10 ShangHai XINDING,NJUPT

Backend computer

Control unit

Transceiver

TA

G

Data

Timing

Power

Coupling element (Coil, Antenna)

Reader

DCSG

+

New diagram of RFID system

2006.10 ShangHai XINDING,NJUPT

+Parameter,initial condition computing

Discrete chaotic mapping

Threshold computing

DCS OUT

Discrete Chaotic Sequence Generator

2

11

kkuxx −=+0

, xu

2006.10 ShangHai XINDING,NJUPT

Public Key:designated

by the users

Sys te m Ke ys

Private Key:

its globally unique S/N

number

Initia l c o nd itio nPa rame te r u

Selection of parameter and initial condition

2006.10 ShangHai

XINDING , NJPUT