UNIVERSITI PUTRA MALAYSIA

AN AUTHENTICATION METHOD FOR SECURE INTERNET TRANSACTION USING SMART CARD AND SECURE

COPROCESSOR

MUSTAFA ABDSALAM AYAD

FK 2002 4

AN AUTHENTICATION METHOD FOR SECURE INTERNET TRANSACTION USING SMART CARD AND SECURE COPROCESSOR

By

MUSTAFA ABDSALAM AYAD

Thesis Submitted in Fulfillment of the Partial Requirement for the Degree of Master of Science in the Faculty of Engineering University Putra Malaysia

July 2002

DEDICATION

To my family ....

i i

Abstract of thesis presented to the Senate of University Putra Malaysia in fulfil lment of the partial requirement for the degree of Master of Science

AN AUTHENTICATION METHOD FOR SECURE INTERNET TRANSACTION USING SMART CARD AND SECURE COPROCESSOR

By

MUSTAFA ABDSALAM AYAD

July 2002

Chairman V. Prakash, Ph. D.

Faculty Engineering

Authentication is the process of confirming an identity. In the context of

network interactions, authentication involves the confident identification of one

party by another party. Authentication of users in distributed systems poses

special problems because, users lack the ability to encrypt and , decrypt. In

most systems today, the user is forced to trust the node he wants to use. In a

more satisfactory design , the user carries a smart card with sufficient

computing power to assist him. This thesis deals with relatively new methods

of authentication using a smart card and secure coprocessor. We analyze two

cases to authenticate a client, depending on the smart card usage. The major

attacks that affect the smart card and the server are applied to our proposed

methods of authentication. The result shows that using the proper system

preparation and proper authentication sequence for our methods the effects

could be minimized .

iii

Abstrak tesis yang d ikemukakan kepada Senat Universiti Putra Malaysia untuk memenuhi keperluan ijazah Master Sa ins

KAEDAH AUTENTIKASI BAGI TRANSAKSI INTERNET YANG SELAMAT MENGGUNAKAN KAD PINTAR DAN PROSESOR BERSAMA YANG

SELAMAT

Oleh

MUSTAFA ABDSALAM AYAD

Pengerusi : V. Prakash,Ph.D.

Fakulti : Kejuruteraan.

Julai 2002

Pengesahan adalah suatu proses pemastian identiti . Di dalam konteks

perhubungan menggunakan rangkaian, pengesahan melibatkan pemastian

identiti suatu pihak oleh pihak yang d ihubungi . Pengesahan oleh pengguna

di dalam sistem teragih mempunyai masalah tersendiri disebabkan pengguna

tidak boleh penyulitan dan menyah sulitan. Kebanyakan sistem pada masa

ini terpaksa mempercayai pelayan yang ingin d igunakan. Reka bentuk yang

lebih memuaskan ialah pengguna menggunakan kad pintar untuk membantu

membuat pengluomputan pengesahan. Tesis ini mengemukakan kaedah

baru untuk pengesahan dengan menggunakan kad pintar dan pembantu

pemproses keselamatan. Kami menganalisa dua kes untuk pengesahan

pengguna, bergantung kepada penggunaan kad pintar. Serangan

d ilaksanakan ke atas kaedah ini yang cuba mengkompromi kad pintar dan

pelayan. Keputusan menunjukkan bahawa dengan pengasingan serta

turutan pengesahan yang betul , keberkesanan serangan boleh dikurangkan

ke tahap yang minima.

iv

ACKNOWLEDGEMENTS

I wish to thank my supervisor, Dr. V. Prakash, for the guidance that he

managed to extend to me during my Master study, and for his efforts to

provide a good research environment, which made this thesis possible.

I am no less grateful to the other committee members Puan Wan Azizun,

Puan Norkamariah Nordin, who were kind enough to read and comment on

my work.

I am grateful to the researchers at Wireless Research Group, Department of

Computer and Communication, for their helpful d iscussion

Last but certainly not least, I wish to thank my wife Hasna and my brother

Khaled for having supported me in such a stable and loving environment,

which has enabled me to come so far.

v

I certify that an Examination Committee met on 15th July 2002 to conduct the final examination of Mustafa Abdsalam Ayad on his Master of Science thesis entitled "An Authentication Method for Secure Internet Transaction Using Smart Card and Secure Coprocessor" in accordance with Universiti Pertanian Malaysia (Higher degree) Act 1980 and Universiti Pertanian Malaysia (Higher Degree) Regulations 1981. The Committee recommends that the candidate be awarded the relevant degree. Members of the Examination Committee are as follows:-

ABDUL RAHMAN RAMLI , Ph. D. Faculty of Engineering Universiti Putra Malaysia (Chairman)

V. PRAKASH , Ph.D. Faculty of Engineering, Universiti Putra Malaysia (Member)

WAN AZIZUN WAN ADNAN, Faculty of Engineering , Universiti Putra Malaysia (Member)

NOR KAMARIAH NOORDIN , Faculty of Engineering, Universiti Putra Malaysia (Member)

SHAMSHER MOHAMAD RAMADILI, Ph.D, ProfessorlDeputy Dean School of Graduate Studies, Universiti Putra Malaysia

Date: 3 0 .lUI. 2002

vi

This Thesis submitted to the Senate of Universiti Putra Malaysia has been was accepted as fulfillment of the partial requirements for the degree of Master of Science.

vi

-

AIN I IDERIS, Ph.D, Professor/Dean School of Graduate Studies, Universiti Putra Malaysia

Date: 1 a SEP 2002

DECLARATION FORM

I hereby declare that the thesis is based on my original work except for quotation and citations, which have been duly acknowledged. I also declare that it has not been previously or concurrently submitted for any other degree at UPM or other institutions.

viii

TABLE OF CONTENTS

Page

DEDICATION . . . . . , . . . . . . . . . . . . . , . . . . '" . . . . . . . . . . . , . . . ... . . . . . . . . , . . . . . . . . . . . . . . . . . . , . . . . . . . ii ABSTRACT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i i i ABSTRAK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. iv ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v APPROVALSHEETS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vi DECLARATION FORM . . . . . . . , . . . . . . . . , . . . . . . . . . , . . . . . . . . . . . . . , . . . . . . . . , . . . . . . . . . , . . . . . . vii i LIST OF TABLES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi LIST OF FIGURES . . . . . . . . . . . . . . . . . , . . . . , . . . . . . . . ,. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv LIST OF ABBREViATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii

CHAPTER 1 INTRODUCTION . . . . . , . . . . , . . . . . . . . . . . . . . . . . . , . . . . . . . . , '" . , . . . . . . . . . . . . . . . . . . . . 1

1 . 1 An Overview . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . , . . . . . . . " . . . . . . . . . . . . . . , . 1 1 . 1 . 1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

1 .2 Threats in Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1 .2 . 1 Network Security Issues . . . . , . . . . . . . . , . . . . '" . . . . . . . . . . . , . . . . ,. . . . . 5 1 .2.2 Security Threats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

1 .3 Inter-Networks (I nternets) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1 .3. 1 Internet Security Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0 1 .3.2 Tasks to Avoid the above Listed Threats. . . . . . . . . . . . . . . . . . . . . . 1 2

1 .4 Authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 2 1 .5 Research Objective . . . '" . . . . . . . . . . . . . . . . . , . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . 1 4 1 .6 Outline of the Thesis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 5

2 LITERATURE REViEW. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6 2. 1 Authentication Systems . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6

2 . 1 . 1 Authentication Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6 2.2 Password-Based Authentication. . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . 21

2.2. 1 Storing User Passwords. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2.2.2 Address-Based Authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 2.2.3 Cryptographic Authentication Protocols . . . . . . . . . . . . '" . . , 24

2.3 Eavesdropping and Server Database Reading . . . . . . . . . . . . . . . . 25 2.4 Trusted I ntermediaries . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

2.4. 1 Key Distribution Center (KDC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2.4.2 Certification Authorities (CAs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 2.4.3 Problem with both KDCs and CAs. . . . . . . . . . . . . . . . . . . . . . . . 29 2.4.4 Multiple KDC Domains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

2.5 Autt.entication of People. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 2.5 . 1 Password-Related Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 2.5 .2 A Login Trojan Horse to Capture Passwords . . . . . . . . . . . , 32 2.5.3 Authentication Tokens . . . . . . . . . . .. . . . . . . . . . . . . . . . .. . . . . . . , . . . . . 33

2.6 Security Handshake Pitfalls . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

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2.6. 1 Login Only. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . 34 2.7 Mutual Authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

2.7. 1 Reflection Attack . . . . . . . . . . . . . .. '" . . . . . . . . . . . . . . . . . . . . . . , . . . . . , 38 2.7.2 Public Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . 39

2.8 Mediated Authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 40 2 .8 .1 Needham-Schroeder Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

2.9 Smart Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . 43 2.9 . 1 Contact vs. Contact-Less I nterfaces . . . . . . . . . . . . . . , . . . . . . 44 2.9.2 Types of Smart Cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ' " . . . . . 44 2.9.3 Cryptographic Smart Card . . . . . . . . . . . . . . , . . . . . , . . . . . . . . . . . . 45 2 .9.4 Classes of Attacks on Security Modules . .. . . . . . . . . . . . . 49 2.9.5 Tamper Resistance versus Tamper Evidence . . . . . . . . 50 2.9.6 Smart Card Threat . . . . . . . . . . . , . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . 55 2.9.7 Classes of Attack. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 2.9.8 Trans-Formation, or Impersonation Attacks. . . . . . . . . . . 58

2. 1 0 Secure Coprocessor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 2. 1 0. 1 Secure Coprocessor Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 2. 10.2 Secure Coprocessors Counteract Threats. . . . . . . . . . . . . 62 2. 1 0.3 Security Partitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 2. 1 0.4 Some of Secure Coprocessor Applications. . . . . . . . . . . . 64

2. 1 1 Various Authentication Protocols . . . . . . . . . . . . . . . . . , . . . . . , . . . . . . . . . . . 66 2. 1 1 . 1 SSL Protocol. . . . . . . . . . . . . . . . . . . . , . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . 66 2.1 1 .2 SET Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

2. 1 2 Server Security . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . , . . . . . , 88 2. 1 2. 1 Server Attacks . . . . . . . . . . . . . . , . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

3 METHODOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 3. 1 System Preparation . . . . . . . . . . . . . . . . . . . . . . , . . . . . , . . . . . . . . . . . . , . . . . . . . . . . . 91

3. 1 . 1 Central Repository Preparation . . . . . . . . . . . . . . . . . . . . . : . . . . . . 91 3. 1 .2 Smart Card Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 3. 1 .3 Workstations Preparation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 3. 1 .4 Central Repository Contents and Functions . . . . . . . , . . . . 96 3. 1 .5 Workstation Contents . . . . . . . . . . , . . . . . , . . . . . . . . . . . . , . . . . . , . . . . . 97

3.2 The Central Repository Authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 3.2 . 1 Authentication of the User to the Central Repository,

Which Issues his Smart Card Case 1 . . . . . . . . . . . . . . . . . . . . 98 3.2.2 Authentication of the User to the CR that Connected

to the Issuer CR Case 2 . . . . . . . . . . . . . . . . . . . . , . . . . . , . . . . . . . . . . . . 1 04 3.3 Method ( 1 ) Using Virtual channel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 06 3.4 Method (2) Using Intermediate Central Repository. . . . . . . . . . . . . 1 1 0 3.5 Implementation of Authentication Methods . . . . , . . . . . . . . . . . . . . . . . . 1 1 3

3 .5 .1 Hardware Requirement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 3 3.5.2 Software Requirement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 4 3.5.3 Flow Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 6

3.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . '" . . . . . . . . . 1 1 9

4 RESULTS and DiSCUSSiON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 20 4 . 1 Smart Card and Secure Coprocessor Functions and Usage. . . 1 21 4.2 The Affect of Major Attacks on (Case 1 ) . . . . , . . . . . . , . . . . . , '" . . . . . . . . 1 22

4.2. 1 Micro Probing . . . . . . . . . . . . . . . . . . . . . . . . . . . . " . . . . . . . . . . . . . . . . . . . . . . . 1 22

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4.2.2 Eavesdropping . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . 1 23 4.2.3 Software Attacks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 23 4.2.4 Fault Generation . . . . . . ' " . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 24 4.2.5 Attacks by Card Issuer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 24 4.2.6 Attacks by the Reader Against the Cardholder

or Data owner . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . 1 24 4 .2.7 Attacks by the Cardholder Against the Reader . . . . , . . . . . . 1 25 4.2.8 Attacks by the Cardholder Against the Data Owner. . . . . 1 25 4.2.9 Attacks by the Cardholder Against the Issuer. . . . . . . . . . . . . 1 26 4.2. 1 0 Effect of Impersonation Attacks . . . . . . . . . . ,. . . . . . . . . . . . . . . . . . . . 1 26

4.2. 1 0. 1 Attacks by Third Parties Using Stolen Cards 1 26 4.2 . 1 0.2 Compromised Workstation Attacks. .. . . . . . . . . . . . . 1 27

4.2. 1 1 Reflection Attack . . . . . . . . . . . , . . . . . . . . . . . . . . . . . , . . . . . . . . . '" . . . . . . . . 127 4.3 The Affect of Major Attacks on (Case 2) . . . . . . . " . . . . . . . . . . . . . . . . . . . 1 28 4.4 SSL, SET and their Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 30

5 CONCLUSION . . . . . . . . . . . . . . . . . . . . . . . . '" . . , . . . . . . . . , . . . . . . . . , '" . , . . . . . . . . . . . . . . . 1 35

5. 1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 35 5.2 Suggestions for Future Work. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 36

REFERENCES .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 37 BIODATA OF THE AUTHOR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 43

xi

LIST OF TABLES

Table Page

1 Credit Card Statistics- VISA and MasterCard . . . . . . . . . . . . 4

2 Comparison of MD5, SHA-1 , and RIPEMD-160. . . . .. . . . 20

3 Cryptographic Card Model 330 Performances . . . . . . . . . . . . 49

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LIST OF FIGURES

Figure Page

1 . 1 Unclear Network Boundaries . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . 8

2. 1 Encryption and Decryption with a Key. . . . . . . . . . . . . . . . . . . . . . . . 1 7

2.2 Encryption and Decryption with Public and Private Keys. 1 8

2.3 IP ( Internet Protocol) Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

2.4 Cryptographic Operation . . . . , . . " . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . 25

2.5 Protocol 1 , Fiddlesticks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

2.6 Protocol 2, Computing Cryptographic Function . . . . . . . . . . . . . . 27

2.7 KDC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

2.8 Two KDCs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

2.9 Protocol 3. . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

2. 1 0 Protocol 4 , A authenticates B Based on his Public key

Signature . . . '" . . . . . . . . . . . . '" . . . . . . . . . . . , . . . . . . . . . . . . . . . . ,. . . . . . . . . . ... . . 35

2 . 1 1 Protocol 4. 1 , Another Variation of Original Protocol . . . . , . . . . 36

2. 1 2 Protocol 5 , Mutual Authentication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

2 . 1 3 Protocol 6, Optimized Mutual Authentication . . . . , . '" . . . . . . . . . 37

2 . 1 4 Protocol 7, Beginning of Reflection Attacks . . . . . . . . . . . . . . . . . . . . 38

2. 1 5 Protocol 8, Second Session of Reflection Attack . . . . . . . , . . . . . 38

2. 1 6 Protocol 9 , Mutual Authentication with Public Keys. . . . . . . . . 39

2. 1 7 Protocol 1 0, KDC Operation in Principle. . . . . . . . . . . . . . . . . . . . . . . . 41

2. 1 8 Protocol 1 1 , KDC Operation in Practice . . . . . . . . . . . . . . . . . . . . . . . . . 41

2. 1 9 Protocoi 12 , Needham-Schroeder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

2.20 Block Diagram of a Cryptographic Card, Chip Contents . . . 46

xiii

2.21 Secure Coprocessor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

2.22 SSL runs above TCP/IP and below high-level application . . . 67

2.23 How a Netscape server authenticates a client certificate . . 73

2.24 Netscape server authenticates a client certificate . . . . . . . . ... . 76

2.25 Shows the participants in the SET system. . . . . . . . . . . . . . . . . . . . . 79

2.26 Construction of dual signature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

2.27 Cardholder sends purchase request. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

3 . 1 Loading and Computing Cryptographic Checksum. . . . . . . . . 94

3.2 Server and Workstations Communication . . . . . . . . . . . . . . . . . . . . . 97

3.3 User A Authenticates the Issuer Central Repository. . . . . . . . . 98

3.4 Hashed Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 00

3.5 Key Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 02

3.6 Steps of Authentication of Case 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 04

3.7 Authentication Using Virtual Channel . . . . . . . . . . . . . . . . . . . . . .. . . . . . 1 09

3.8 Method (2) , Using Intermediate Central Repository . . . . . . . . . . 1 1 0

3.9 Flow Chart Case 1 . . . . . . . . . . . ' . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 6

3. 1 0 Flow Chart Case 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1 7

xi

LIST OF ABBREVIATIONS

ACL Access Control List

ATM Automatic Tal ler machine

CA Certification Authority

CBC Cipher Block Chaining

CC Cryptographic Checksum

CIA Central I ntelligence Agency

CPU Central Processing Unit

DES Data Encryption Standard

ON Distinguished name

DSA Digital Signature Algorithm

DSS Digital Signature Standard

ECB Electronic Code Book

FAT File Allocation Table

F IPS Federal Information ProceSSing Standard

FLs Financial Institutions

H (M) Hash Code for Message M

HTTP Hyper Text Transport Protocol

IMAP Internet Messaging Access Protocol

ISO International Standard Organization

KDC Key Distribution Center

KEA Key-exchange algorithms

KGB Russian Equivalent of the CIA

KLP Key Loader Program

xv

LDAP

MD4

MD5

NCL

01

OIMD

PI

PIMD

PKCS

PKI

ROM

RSA

RSA

SIN

SET

SHA

SSL

TCPIIP

VLSI

Lightweight Directory Access Protocol

Message-Digest Algorithm 4

Message-Digest Algorithm 5

National Consumer's League

Order Information

Order Information Message Digest

Payment Information

Payment Information Message Digest

Public key Cryptography Standard

Public Key Infrastructure Functions

Read only Memory

(Rivest, Shamir and Adleman)

A public key Cryptographic Algorithm Named for its Inventors

Serial Number

Secure Electronic Transaction.

Secure Hash Algorithms

Secure Sockets Layer

Transmission Control Protocolllnternet Protocol

Very Large Scale Integration

xv

1 .1 An Overview

CHAPTER 1

INTRODUCTION

Security in networks of computers is an important issue, although networks

raise new issues in security, famil iar topics appear in the list of solutions to

network security problems. The problems are loss of confidentiality, integrity,

and avai lability. The solutions to these technologies include, encryption,

access controls, strong authentication, and protocols. In fact, networks can be

viewed as more complex example of computing systems. Threats arise at

d ifferent points based on different technologies, so that many program

development and operating system security concepts and controls apply to

networks as well . Computer networks offer several advantages over single­

processor systems, such as:

1 . Resource Sharing. Users of a network can access a variety of

resources through the network. Sharing databases, data and program

files, and other resources reduces maintenance and storage costs while

providing each user with improved access.

2. Distributing the Workload. The use of single system varies as users join

and leave a system. The degree of fluctuation of workload for a single user

can be moderated in a network, so the workload can be shifted from a

heavily loaded system to an underused one.

3. Increased Reliability. Because a computing network consists of more

than one computing system, the fai lure of one system or just one

component need not necessarily block users from continuing to compute.

If similar systems exist, users can move their computing to other systems

when one system fails.

4. Expandability. Network system can be expanded easily by adding new

nodes. This expansion of user-base can occur without the manager of any

single system having to take special action {Pfleeger 1 997}.

Computing networks have similar characteristics. The network must ensure

integrity of data, secrecy of data and availabil ity of services. Each user

accesses the network through a single operating system, which also includes

network interface responsibilities. Users sti l l expect the operating systems to

enforce the security pOlicies of the network. However, in a network the

operating systems at the two ends of the communication, as well as the

operating systems of al l computers in between, must cooperate to enforce

security (PfJeeger 1 997) .

1 .1 .1 Motivation

The security of credit card transactions remains the number one concern both

for Internet users who have yet to make an online purchase, and for those

who have performed an online transaction. The US National Consumer 's

League Internet Fraud Watch (NCL) has reported that American consumers

2

lost over $3.2 million to online scams in 1 999, a 38 percent increase over the

previous year. The vast majority of cases reported to the NCL involved

payments by cheque or money order, with credit card transactions accounting

for only three percent of cases. An online survey in January, March 2000

found that 41 percent of regular Internet users had shopped online two to four

times, whi le 22 percent had made one online purchase. Significantly, 1 9

percent had made over 1 0 online transactions. Due to continued strong

growth i n the number of Internet users, it seems likely the total number of

people shopping online and the proportion of frequent shoppers will continue

to i ncrease. Internet-related fraud is certainly a matter for concern, and

authorities around the world are active in combating a range of illegal

activities being conducted over the Internet. One of the most widely publicized

cases of credit card fraud occurred in the US, where a group of web-based

companies made smal l , recurrent charges to hundreds of thousands of credit

cards (Phantom Menace 2001 , Meridien Research 2001 ) .

I mprovements in security and encryption technology will make it more d ifficult

for crim inals to intercept online transactions. Both Netscape Navigator and

Microsoft Internet Explorer use Secure Sockets Layer (SSL) to encrypt data

before sending it over the Internet. SSL scrambles personal data and provides

an unbroken key or lock that appears in the bottom of the browser window.

This technology provides a secure connection that keeps data private during

transmission over the Internet, however it does not authenticate the parties at

either end of the transaction.

3

Table 1: Credit Card Statistics- VISA and MasterCard.

As at Fiscal No. of Cards No. of # Of Cards No. of Cards $ Amount Year Ending in Accounts with Reported Fraudulently of Oct. 31. Circulation balance Lost or used. Fraudulent

(Millions). (Millions). Stolen. Accounts written off (millions).

1 985 1 4.0 7.3 330,380 21 ,026 $1 7.54 1 986 1 5.5 7.9 378,239 22,326 $1 8.61 1 987 1 7.6 8.8 408,239 23,91 3 $1 5.78 1 988 1 9.4 9.5 460,348 25,773 $1 5.63 1 989 20.4 1 0.3 522,204 30,91 9 $1 9.20 1 990 23.2 1 1 . 1 520,716 32,851 $28.90 1 991 24.3 1 1 .8 623,946 53,968 $44.60 1 992 24.4 1 2.2 650,088 61 ,234 $63.50 1 993 25.0 1 2.4 674,988 63,442 $75.20 1 994 27.5 1 3.2 731 ,052 63,635 $70.60 1 995 28.8 1 3.6 648,824 66, 1 09 $72.64 1 996 30.2 14. 1 794,996 77,740 $83.63 1 997 31 .9 15.0 858,625 89,982 $88.08 1 998 35.3 1 6.0 895,81 7 1 26,384 $1 04.80 1 999 37.7 1 7.3 823,934 1 32,836 $1 34. 1 0 2000 40. 1 1 8.5 805,580 1 1 2,070 $156.38 2001 44. 1 1 9.6 81 3,624 1 1 6, 1 39 $1 42.27

VISA International and MasterCard International , with support from many of

the world 's top financial institutions, are presently working to develop a more

advanced encryption process called Secure Electronic Transaction (SET) .

SET involves a system of digital certificates provided by card issuers, and

encryption. It enables the identity of both merchant and cardholder to be

authenticated, and also ensures that neither the merchant or cardholder 's

bank sees the purchaser's credit card number (Konrad et al . 2000).

As shown in Table 1 , the number of cards in circulation, the number of

accounts with balance, the number of cards reported lost or stolen and the

numbers of cards fraudulently used are increased as the years going on from

4

1985-2001. The number of cards fraudulently used at 1985 is 21,026 cards,

while it is 116,139 at 2001 (Canadian Bankers Association 2001).

Enhancement of authentication protocols and encryption technology improved

the security and makes it more difficult for hackers to intercept or tamper with

online transactions. We propose the use of smart card and secure

coprocessor to provide a highly secure environment for the Internet

transactions. Two methods of authentication are proposed in this thesis,

which can provide a secure environment for handshaking and secure

transaction processing .

1 .2 Threats in Networks

I n the fol lowing sections we look to network security issues and reasons for

network security problems, and security threats considering damage to

confidentiality, integrity and availabil ity, and then looking to many ways to

accomplish threats to the network.

1 .2.1 Network Security Issues

Networks have several security problems for several reasons. In the next

sections we wil l explain each of the reasons, which are causing the network

security problems.

5

1 .2.1 .1 Sharing

Because of the resource sharing of networks, more users have the potential

to access networked systems than single computers. Perhaps worse access

is afforded to more systems, therefore access controls for single systems may

be inadequate in the networks.

1 .2.1 .2 Complexity of System

As we know that an operating system is the most complicated piece of

software ever produced. Reliable security is difficult if not possible on large

operating system, especially one not designed for security. A network

combines two or more dissimilar operating systems. Therefore, a network

operating system/control system is l ikely to be more complex than an

operating system for single computer system. This compl�xity l imits

confidence in the security of a network.

1 .2.1 .3 Unknown Perimeter

The expand abil ity of a network also implies uncertainly about the network

boundary. One host may be a node on two different networks, so that

resources on one network are accessible to the users of other networks as

well . Although wide accessibi lity is an advantage, this unknown or

uncontrolled group of possibly malicious users is a security disadvantage. A

similar problem occurs when new hosts can be added to the network. Every

6

network node must be able to react to the possible presence of new,

untrustable hosts. Figure 1 . 1 points out the problems in defining the

boundaries of a network. Notice that, users on a host in network D may be

unaware of the potential connections from users of networks A and B .

1 .2.1 .4 Many Points of Attack

A simple computing system is a self-contained unit. Access controls on one

machine preserve the secrecy of data on that processor. However, when a fi le

is stored in a network host remote from the user, the fi le may pass through

many hosts to get to the user. Although the administrator of one host may

enforce rigorous security policies, that administrator has no control over other

hosts in the network. The user has to depend on the access control

mechanism of al l of these systems.

1 .2.1 .5 Anonymity

An attacker can mount an attack from thousands of miles away and thus

never have to touch the system attacked or come into contact with any of its

administrators or users. The attack can be passed through many other hosts,

in an effort to disguise from where the attack originated . Finally, computer-to­

computer authentication is not the same as for humans to computers; secure

d istributed authentication requires thought and attention to detail .

7

1 .2.1 .6 Unknown Path

There may be many paths from one host to another. Suppose that a user on

one host wants to send a message to user on another host, that message

might be routed through different hosts before arriving at destination host.

Source host may provide acceptable security, but not intermediate nodes.

Network users seldom have control over the routing of their messages.

N etwork A

NetworkB

.,,­./

--'''- ... - ..... \

I I I I ,

� J \ .'

\, ___ I-!el�� p _____ . r'

Figure 1 .1 : Unclear Network Boundaries

1 .2.2 Security Threats

We looked at al l the parts of a network; considered damage to confidentiality,

integrity, and availabil ity; and hypothesized the kinds of attack that could

cause this damage.

8