Security Analysis on Wireless LAN protocols HORI Yoshiaki - - PowerPoint PPT Presentation

SLIDE 1

ETRI-ISIT 1st joint seminar 1

Security Analysis on Wireless LAN protocols

HORI Yoshiaki hori@csce.kyushu-u.ac.jp Kyushu University / ISIT

SLIDE 2

ETRI-ISIT 1st joint seminar 2

Contents

・ S e c u r i t y a n a l y s i s

• n

I E E E 8 2 . 1 1 i

‐ S h

• r

t s u m m a r y

• f

C . H e a n d J . C . M i t c h e l l , “ S e c u r i t y A n a l y s i s a n d I m p r

• v

e m e n t s f

• r

I E E E 8 2 . 1 1 i , ” N D S S 5 , F e b r u a r y 2 5

・ S e c u r i t y a n a l y s i s

• n

M I S p r

• t
• c
• l

‐ Y e t a n

• t

h e r w i r e l e s s L A N p r

• t
• c
• l

b a s e d

• n

I E E E 8 2 . 1 1 p h y s i c a l l a y e r

SLIDE 3

ETRI-ISIT 1st joint seminar 3

Wireless LAN and Security

• Wireless LAN (WLAN)

– WLAN uses wireless media instead of wired media in order to provide connectivity for a terminal.

• A wireless terminal is connected with Access Point (AP) by using of

wireless media.

– WLAN provides mobility, no wire → WLAN enables easily to build LAN – Currently WLAN become widely deployed.

• WLAN security

– WLAN security has become a serious concern for many

• rganizations.

– Security requirements for a WLAN

• Data condidentiality
• Integrity
• Mutual authentication
• Availability

SLIDE 4

ETRI-ISIT 1st joint seminar 4

WLAN security model

Network Network

Wireless terminal (Supplicant) Access Point (AP) (Authenticator) (Authentication Server) Adversary Attack Eaves dropping

SLIDE 5

ETRI-ISIT 1st joint seminar 5

Wireless Threats

(by C. He and J. C. Mitchell, Stanford Univ.)

• Wireless Threats

– Threat 1: Passive Eavesdropping – Threat 2: Message Injection – Threat 3: Message Deletion and Interception – Threat 4: Masquerading and Malicious AP – Threat 5: Session Hijacking – Threat 6: Man-in-the-Middle – Threat 7: Denial of Service Threats 1, 2, and 3: attack all three type of frames in the Link Layer Threats 4, 5, and 6: defeat mutual authentication Threats 7: interferes with availabilit

SLIDE 6

ETRI-ISIT 1st joint seminar 6

IEEE 802.11i overview

・I E E E s t a n d a r d a p p r

• v

e d a n d p u b l i s h e d

• n

J u n e 2 4 ・D e s i g n e d t

• p

r

• v

i d e e n h a n c e d s e c u r i t y i n t h e M e d i a A c c e s s C

• n

t r

• l

( M A C ) l a y e r f

• r

8 2 . 1 1 w i r e l e s s n e t w

• r

k s

‐8 2 . 1 1 i w

• r

k s w e l l f

• r

d a t a c

• n

f i d e n t i a l i t y , i n t e g r i t y , a n d m u t u a l a u t h e n t i c a t i

• n

.

・D e f i n e d R

• b

u s t S e c u r i t y N e t w

• r

k A s s

• c

i a t i

• n

( R S N A ) w h i c h p r

• v

i d e s

‐t w

• d

a t a c

• n

f i d e n t i a l i t y p r

• t
• c
• l

s ;

・T e m p

• r

a r y K e y I n t e g r i t y P r

• t
• c
• l

( T K I P ) ・C

• u

n t e r

• m
• d

e / C B C

• M

A C P r

• t
• c
• l

( C C M P ) w i t h A E S

• 1

2 8 ( 1 2 8 b i t K e y a n d 1 2 8 b i t B l

• c

k s i z e )

‐A u t h e n t i c a t i

• n

a n d k e y m a n a g e m e n t p r

• t
• c
• l

・E x t e n s i b l e A u t h e n t i c a t i

• n

P r

• t
• c
• l

( E A P ) s c h e m e , e . g . E A P

• T

L S , p r

• v

i d e s m u t u a l a u t h e n t i c a t i

• n

. ・4

• w

a y h a n d s h a k e e n a b l e s t

• s

h a r e P a i r w i s e T r a n s i e n t K e y ( P T K ) d e r i v e d f r

• m

t h e i r P a i r w i s e M a s t e r K e y ( P T K ) .

・A l s

• s

u p p

• r

t e d p r e

• R

S N A f

• r

c

• m

p a t i b i l i t y w i t h 8 2 . 1 1

‐W i r e d E q u i v a l e n t P r i v a c y ( W E P )

SLIDE 7

ETRI-ISIT 1st joint seminar 7

Data confidentiality and Integrity

・ C C M P a p p e a r s t

• p

r

• v

i d e s a t i s f a c t

• r

y d a t a c

• n

f i d e n t i a l i t y , i n t e g r i t y , a n d r e p l a y p r

• t

e c t i

• n

f

• r

d a t a p a c k e t s a g a i n s t t h r e a t s 1 , 2 a n d 3 . ・ H

• w

e v e r , t h r e a t s 1 , 2 a n d 3 r e m a i n w i t h m a n a g e m e n t f r a m e s a n d c

• n

t r

• l

f r a m e s b e c a u s e t h e s e f r a m e s a r e n e i t h e r e n c r y p t e d n

• r

a u t h e n t i c a t e d b y t h e l i n k l a y e r e n c r y p t i

• n

a l g

• r

i t h m .

SLIDE 8

ETRI-ISIT 1st joint seminar 8

Authentication and Key Management

・I f t h e c

• m

p l e t e R S N A h a n d s h a k e s a r e p e r f

• r

m e d , t h e a u t h e n t i c a t i

• n

a n d k e y m a n a g e m e n t p r

• c

e s s a p p e a r t

• b

e s e c u r e . ・H

• w

e v e r , s i n c e a n a d v e r s a r y c a n i n t e r f e r e w i t h e a r l y s t a g e s i n R S N A h a n d s h a k e s , i t m a y p r e v e n t c

• m

p l e t i

• n
• f

t h e R S N A . ・S

• m

e a t t a c k s f

• r

8 2 . 1 1 i

‐S e c u r i t y l e v e l r

• l

l b a c k a t t a c k

・B

• g

u s b e a c

• n

a n d b

• g

u s p r

• b

e r e s p

• n

s e f r

• m

a n a u t h e n t i c a t

• r

( a c c e s s p

• i

n t ) , a n d b

• g

u s a s s

• c

i a t i

• n

r e q u e s t .

‐R e f l e c t i

• n

a t t a c k

• n

t h e 4

• w

a y h a n d s h a k e

SLIDE 9

ETRI-ISIT 1st joint seminar 9

Availability

・ K n

• w

n D

• SA

t t a c k s ・ M i c h a e l A l g

• r

i t h m C

• u

n t e r m e a s u r e ( i n T K I P )

‐ N

• t

a f f e c t e d w i t h C C M P

・ R S N I E ( R S N I n f

• r

m a t i

• n

E l e m e n t ) P

• i

s

• n

i n g ・ 4

• W

a y H a n d s h a k e B l

• c

k i n g ・ F a i l u r e R e c

• v

e r y

SLIDE 10

ETRI-ISIT 1st joint seminar 10

Known DoS Attacks

・A n a d v e r s a r y c a n e a s i l y f

• r

g e t h e m a n a g e m e n t f r a m e s a n d t h e c

• n

t r

• l

f r a m e s t

• l

a u n c h a D

• S

a t t a c k .

‐T h e m

• s

t e f f i c i e n t a t t a c k i s t

• f
• r

g e a n d r e p e a t e d l y s e n d D e a u t h e n t i c a t i

• n
• r

D e a s s

• c

i a t i

• n

f r a m e s . T h e s e a t t a c k s p e r s i s t e v e n i f 8 2 . 1 1 i i s u s e d . ‐T h e r e a r e a l s

• s

e v e r a l D

• Sa

t t a c k s t h a t e x p l

• i

t t h e u n p r

• t

e c t e d E A P m e s s a g e s i n 8 2 . 1 X a u t h e n t i c a t i

• n

. H

• w

e v e r , t h e s e v u l n e r a b i l i t i e s f

• r

t u n a t e l y c a n b e e l i m i n a t e d i n 8 2 . 1 1 i b y s i m p l y i g n

• r

i n g t h e s e m e s s a g e s .

・E A P O L ( E A P

• v

e r L A N )

• S

t a r t , E A P O L

• S

u c c e s s , E A P O L

• F

a i l u r e , E A P O L

• L
• g
• f

f

SLIDE 11

ETRI-ISIT 1st joint seminar 11

Summary: 802.11i security

・ S a t i s f a c t

• r

y d a t a c

• n

f i d e n t i a l i t y , i n t e g r i t y , a n d r e p l a y p r

• t

e c t i

• n

f

• r

d a t a p a c k e t s i s p r

• v

i d e d b y u s i n g

• f

C C M P ( A E S ) . ・ M u t u a l a u t h e n t i c a t i

• n

i s p r

• v

i d e d b y E A P

• T

L S a n d 4

• w

a y h a n d s h a k e . ・ I n

• r

d e r t

• s

u p p

• r

t a b

• v

e f e a t u r e s a n d t

• k

e e p u p p e r c

• m

p a t i b i l i t y w i t h I E E E 8 2 . 1 1 a n d I E E E 8 2 . 1 X ( p r e

• R

S N A ) , w e s h

• u

l d c

• n

s i d e r a v a i l a b i l i t y .

SLIDE 12

ETRI-ISIT 1st joint seminar 12

MIS Protocol

・B e t w e e n a t e r m i n a l ( M N : m

• b

i l e n

• d

e ) a n d a b a s e r

• u

t e r ( B R ) . ・M I S p r

• t
• c
• l

p r

• v

i d e s s e c u r i t y f e a t u r e s :

‐M u t u a l a u t h e n t i c a t i

• n

b e t w e e n M N a n d B R ‐S h a r i n g s e s s i

• n

k e y b e t w e e n M N a n d B R ‐P a c k e t a u t h e n t i c a t i

• n

a n d D a t a e n c r y p t i

• n

・A d v a n t a g e s

‐F a s t a u t h e n t i c a t i

• n

a n d D a t a e n c r y p t i

• n

・M I S p r

• t
• c
• l

c a n w

• r

k a s W L A N s e c u r i t y p r

• t
• c
• l

‐M I S u s e s p s e u d

• a

d h

• c

m

• d

e ( I E E E 8 2 . 1 1 p h y s i c a l l a y e r )

• f

I E E E 8 2 . 1 1 n e t w

• r

k i n t e r f a c e c a r d .

IP MIS protocol IEEE802.11 Pseudo AdHoc mode Protocol Layers

SLIDE 13

ETRI-ISIT 1st joint seminar 13

Design and Standardize

• Some ideas of MIS protocol were written in 2001

– “Fast Authentication System for Secure Wireless Internet Services” (K. Fujikawa, H. Nakano, M. Ohta, M. Hirabaru, H. Mano, and K. Ikeda) IPSJ SIGDPS technical report, 2001-DPS-107, March 2002

• Protocol specifications were approved by Mobile Broadband

Association (MBA) and published on their Web. http: / / www.mbassoc.org/

• Protocol Documents

(but these are written in only Japanese) – MBA standard 0201, “MIS protocol specification ver. 1.02” (announced on April 2004) – MBA standard draft 0301, “MISAUTH protocol specification” (annouced on June 2004)

SLIDE 14

ETRI-ISIT 1st joint seminar 14

MIS protocol time chart

Mobile Node (MN) Base Router (BR) Authentication Server (AS)

beacon

• Auth. Request

Access Request Access O.K.

• Auth. success

( t )

( s, t, Hk(t) ) ( s, t, Hk(t) ) ( Hk(s) )

Hk(s) is shared as session key s generated Hk(s) generate

Hk(s)

k: Shared Key s: seed t: timestamp Hk(): Keyed Hash Func.

SLIDE 15

ETRI-ISIT 1st joint seminar 15

Objective

・ S e c u r i t y a n a l y s i s

• n

M I S p r

• t
• c
• l
• n

W i r e l e s s L A N . ・ W e a t t e m p t t

• e

v a l u a t e M I S p r

• t
• c
• l

s e c u r i t y .

‐ C

• n

f i d e n t i a l i t y a n d I n t e g r i t y ‐ A u t h e n t i c a t i

• n

a n d K e y M a n a g e m e n t ‐ A v a i l a b i l i t y

SLIDE 16

ETRI-ISIT 1st joint seminar 16

Confidentiality and Integrity

・M I S p r

• t
• c
• l

p r

• v

i d e s d a t a e n c r y p t i

• n

a n d i n t e g r i t y b y u s i n g

• f

A E S

• C

B C

• 1

2 8 b i t a n d H M A C

• M

D 5 .

‐I t i s a p p r

• p

r i a t e w i t h e n

• u

g h k e y l e n g t h r a t h e r t h a n W E P .

・M I S p r

• t
• c
• l

a l s

• d
• e

s n

• t

p r

• v

i d e e n c r y p t i

• n

a n d i n t e g r i t y c h e c k

• f

c

• n

t r

• l

m e s s a g e s b e f

• r

e s h a r i n g s e s s i

• n

k e y .

‐M I S c

• n

t r

• l

m e s s a g e :

・B e a c

• n

m e s s a g e ・A u t h e n t i c a t i

• n

R e q u e s t m e s s a g e ・A u t h e n t i c a t i

• n

S u c c e s s m e s s a g e ・A u t h e n t i c a t i

• n

F a i l t u r e m e s s a g e ・S e s s i

• n

c l

• s

e m e s s a g e

SLIDE 17

ETRI-ISIT 1st joint seminar 17

Authentication

・ M I S p r

• t
• c
• l

c a r r i e s

• u

t m u t u a l a u t h e n t i c a t i

• n

b e t w e e n M

• b

i l e N

• d

e ( M N ) a n d B a s e R

• u

t e r ( B R ) . ・ M I S p r

• t
• c
• l

e n a b l e s m e s s a g e a u t h e n t i c a t i

• n

a f t e r s h a r i n g s e s s i

• n

k e y .

‐ A u t h e n t i c a t i

• n

f a i l u r e m e s s a g e a l s

• i

s u s e d a t r e n e w

• f

s e s s i

• n

k e y . T h e p r

• t
• c
• l

s p e c i f i c a t i

• n

s a i d “ a u t h e n t i c a t i

• n

i s n

• t

p r

• v

i d e d f

• r

a u t h e n t i c a t i

• n

f a i l u r e m e s s a g e . ”

SLIDE 18

ETRI-ISIT 1st joint seminar 18

Availability

・ M I S p r

• t
• c
• l

h a s s

• m

e w e a k n e s s f

• r

D

• S

a t t a c k b y u s i n g

• f

f

• r

g e d c

• n

t r

• l

m e s s a g e s b e c a u s e

• f

a l a c k

• f

a u t h e n t i c a t i

• n

.

‐ B e a c

• n

m e s s a g e ‐ A u t h e n t i c a t i

• n

f a i l u r e m e s s a g e

・ F

• r

g e d a u t h e n t i c a t i

• n

f a i l u r e m e s s a g e a t t h e a u t h e n t i c a t i

• n

p r

• c

e s s a n d t h e r e n e w

• f

s e s s i

• n

k e y .

‐ A u t h e n t i c a t i

• n

r e q u e s t m e s s a g e

SLIDE 19

ETRI-ISIT 1st joint seminar 19

Countermeasure of MIS protocol

・ F

• r

g e d a u t h e n t i c a t i

• n

f a i l u r e m e s s a g e

‐ W a i t i n g t i m e

• u

t

・ F

• r

g e d a u t h e n t i c a t i

• n

f a i l t u r e m e s s a g e a t r e n e w s e s s i

• n

k e y

‐ N e w c

• n

t r

• l

m e s s a g e f

• r

r e n e w s e s s i

• n

k e y i s r e q u i r e d .

SLIDE 20

ETRI-ISIT 1st joint seminar 20

Summary

・ M I S p r

• t
• c
• l

p r

• v

i d e s c

• n

f i d e n t i a l i t y , i n t e g r i t y , m u t u a l a u t h e n t i c a t i

• n

e q u i v a l e n t t

• I

E E E 8 2 . 1 1 i . ・ M I S p r

• t
• c
• l

a l s

• s
• m

e w e a k n e s s a g a i n s t D

• Sa

t t a c k l i k e I E E E 8 2 . 1 1 i . ・ W e c a n m e a s u r e a g a i n s t D

• Sa

t t a c k b y a l i t t l e m

• d

i f i c a t i

• n
• f

M I S p r

• t
• c
• l

b e c a u s e i t i s s

• s

i m p l e .