Wireless Sec Pres

8/9/2019 Wireless Sec Pres

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Security Issues, Concepts and

Strategies in Wireless AndMobile Systems

By: Imad Jawhar


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Outline

Introduction

!he wireless en"ironment and systems

Concepts and terminologies used in

wireless security

Some commonly used wireless and mobile

systems and protocols

Wireless application protocol #WA$%


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Wireless transaction protocol #W!$%

Wireless transport layer security #W!&S%

protocol

Some additional concerning WA$ security

Some research and 'uture directions in

wireless system security

Conclusions


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!he Wireless (n"ironment

Communications in the wireless en"ironment has

its own issues and challenges)

*enerally, it has the 'ollowing characteristics:+ elati"ely low bandwidth and data rate)

+ elati"ely high error rates)

+-eed 'or low power consumption to preser"e battery

li'e o' mobile systems)

+ Mobility o' the nodes adds more comple.ity because o'

topology changes)


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+Signal 'ading)

+/ando'' issues)

+And other challenges)

+All o' these issues a''ect design and design 'or

security


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!here e.ists many 'orms o' wireless

communications and networ0ing, and the

number o' these 'orms dynamicallyincreasing)

!he 'ollowing is a list o' the some "ery

popular 'orms o' wireless communications)


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Satellite Communications:

+1ses microwa"e lin0s and pro"ides global

connection o' many networ0 in'rastructures)

+!hree types o' satellites:

*(O: *eostationary (arth Orbit Satellites)

M(O: Medium (arth Orbit Satellites) &(O: &ow (arth Orbit Satellites)


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Cellular -etwor0s:

+Widely used recently) 2uic0ly increasing in

popularity all o"er the world)

+*eographic area is di"ided into cells)

+(ach cell is ser"iced by a base station #BS%)

+Se"eral stations are ser"ed by a Mobile!elecommunications Switching O''ice

#M!SO%, or a similar structure)


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+Base station connects mobile users to M!SO)

+M!SO connects base station #BS3s% to

telephone switching o''ice)+!he 'irst generation o' systems was AM$S

#Ad"anced Mobile $hone Ser"ice% which used

analog communications


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!he second generation uses digital tra''ic

channels, encryption, error detection,

correction, and allow channel access to bedynamically shared by all users)


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!hird generation systems will ha"e:

+4oice 5uality that is comparable to public

switched telephone networ0s)

+/igher data rates)

+Symmetrical and asymmetrical data

transmission rates)+Support 'or both pac0et and circuit switched

data ser"ices)


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+Adapti"e inter'ace to the Internet to re'lect

common asymmetry between inbound and

outbound tra''ic)+More e''icient use o' a"ailable spectrum

+Support 'or wide "ariety o' mobile )e5uipment)

+More 'le.ibility to accept new ser"ices andtechni5ues)


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Cordless Systems:

+1sed inside homes and buildings)

+Allow wireless communications between

cordless de"ices such as a telephone to a single

multiple base stations using !6MA #!ime

6i"ision Multiple Access% and !66 #!ime6i"ision 6uple.% communications)


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Wireless &ocal &oop #W&&%:

+Increasingly more popular way to pro"ide

wireless last mile connections between the enduser and the local switching telephone center)

+Allows reduction in installation cost, and time)

+Selecti"e installation is possible #only installwhen customer desires ser"ice, not in

anticipation o' the customer desiring ser"ice%)


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Mobile I$:+Allows nomadic access to the Internet 'rom

di''erent access points)+A user is able to maintain connectability to the

Internet while mo"ing 'rom one access point toanother)

+It uses process registration, agent solicitation,mo"e detection, and tunneling to achie"e thisob7ecti"e)


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Wireless &ocal Area -etwor0s #W&A-s%:

+apidly becoming "ery popular)

+!his is due to many characteristics such as:

-eed 'or mobility)

Cost e''ecti"eness)

Con"enience) apid deployment ability)


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6ecrease in si8e o' electronic and digital e5uipment)

Speed o' mobile computing de"ices)


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!here are 'our types o' wireless &A-s )

&A- (.tension:

+$ro"ide wireless connections o' mobile

computing units to a wired networ0)

+1sed in manu'acturing, stoc0 e.change, and

warehouses)


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Cross9building Interconnect:

+1sed to pro"ide wireless connections between

buildings)+1ses microwa"e communications with dish

shaped antennas)

+More o' a lin0 than a &A-)


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-omadic Access:

+1sed to pro"ide connecti"ity 'rom mobile units

such as a laptop, $6A or other computingde"ices to a 'i.ed campus networ0 per e.ample)


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Ad /oc -etwor0ing:

+Also called rapidly deployable networ0s)

+An increasingly popular 'orm o' establishing

networ0s between mobile computing de"ices,

such as laptops, computers inside mo"ing

"ehicles)

+!he temporary wireless networ0 is establisheddynamically on the 'ly)


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+4ery dynamic in nature because topology

changes while nodes mo"e 'rom one location to

another, and nodes dynamically mo"e in andout o' each other3s range and are added and

deleted to the networ0 all together)


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+e5uire robust communications algorithms and

protocols, which ha"e the 'ollowing

characteristics: Can 5uic0ly adapt to the changing networ0

topology)

Maintain e''icient connecti"ity and routing between

"arious nodes while wireless lin0s are lost andestablished dynamically as nodes mo"e in and out o'

each other3s range)


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+!here are numerous applications 'or Ad /oc

-etwor0s, such as:

!actical military operations) Con'erences)

Campus and classroom en"ironments)

6isaster reco"ery)

Search and rescue operations)

And so on)


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Bluetooth:

+A wireless communications protocol)

+Originally started by (ricsson)

+2uic0ly became adopted by a consortium o'

companies in the computer industry)

+*rew 'rom a 'ew companies to thousandsincluding all o' the ma7or companies in the

industry)


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+6esigned to establish and maintain connections

between "arious computing de"ices and

electronic e5uipment such as: Computers,cellular phones, $6A3s, and so on)

+!his is done wirelessly a"oiding the need 'or

wires to establish the connections)

+Intended to wor0 in a close pro.imity

en"ironments such as homes, o''ices,

classrooms, hospitals, airports, etc)


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+Connections are established by designating

master and sla"e nodes)

+It uses pro'iles 'or di''erent de"ices, whichcharacteri8e the applications)

+!here are types o' communication lin0s which

are multiple.ed o"er the same #adio

re5uency%:

Synchronous Connection9oriented #SCO% 'or "oice)

Asynchronous connectionless #AC&% lin0s 'or data)


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+1ses re5uency9hopping spread spectrum with

a high rate ;sec to reduce

inter'erence, and pro"ide low power, and lowcost o' radio communications)

+Operates in the ISM band at ?)@ */8 with a

transmission o' ; to ;== mW, and a range o' ;=

to ;== meters, and a ma.imum bit rate o' ;Mbps, and an e''ecti"e data trans'er rate o' ?;

bps)


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D=?);; wireless standard

!his is a wireless &A- standard)

which is increasingly being adopted by

many wireless de"ices to establishcommunications at the physical and datalin0 layers o' the OSI model)

In ?=== "endors sold around a millionD=?);; networ0 inter'ace cards, and salesare e.pected to go up to E)F million in ?==@


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Security Issues

Importance o' wireless systems)

In e"ery aspect o' our li"es)

Sensiti"ity o' in'ormation shared onwireless systems #increasingly important%'inancial, personal, social, con'idential, etc)

e.ample: wireless cameras #watching nannyand baby in houseGthe whole bloc0watching%)


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Security ser"ices needed

#especially in e9commerce transactions%

User authentication: !he process o'

pro"ing to the system that the user is whomhe>she says he>she is)


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Data authentication: It is 'urther subdi"ided into

two sub9ser"ices)

!he 'irst is data integrity, which is the process o'guaranteeing to the recei"er that the data was not

changed during the transmission process)

!he second is data origin authentication is the

process o' pro"ing to the recei"er that the data was

actually sent by the stated sender)


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Data confidentiality: It ensures that

unintended parties are not able to read the

data while in transit) (ncryption is used toachie"e this ob7ecti"e)


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Authorization: It is the process o' ensuring that only authori8ed users are

allowed to access the data>resources) In a Hclosed systema user is not allowed access without e.plicit authori8ation)!ypically, this is the desired model o' secure systems) Onthe other hand, in an Hopen system a user is allowedaccess #implicit authori8ation% unless speci'ically

deauthori8ed by the system) !he latter model isundesirable 'or the design o' secure systems, unlessabsolutely necessary because o' the nature o' theapplication #a public library, etc)%


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Audit: An audit trail is used to 0eep trac0

o' who, when, what, and how transactions

too0 place in a system) !his audit trail canbe an essential tool 'or a'ter the 'act

analysis in cases intentional or unintentional

security attac0s) It can also be used byintrusion detection algorithms to detect and

pre"ent current and 'uture attac0s)


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Non-repudiation: !his is an important ser"icethat is essential 'or the proper operation o'

certain e9commerce transactions) It is the

process o' guaranteeing that a certain user

actually did issue a certain order or re5uired acertain transaction) -on9repudiation is usually

implemented using digital signatures, which are

uni5ue to users and pro"ide proo' that a

particular user initiated a particular transaction)


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Some Commonly Used Mobile and

Wireless and Mobile Systems and

Protocols: D=?);;

Bluetooth

Mobile I$


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IEEE 802.11

!his is a wireless &A- standard)

which is increasingly being adopted by

many wireless de"ices to establishcommunications at the physical and datalin0 layers o' the OSI model)

In ?=== "endors sold around a millionD=?);; networ0 inter'ace cards, and salesare e.pected to go up to E)F million in ?==@


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!he D=?);; architecture uses the wired

e5ui"alent pri"acy protocol #W($%)

6ata is encrypted with W($ to protect thewireless lin0 between clients and access

points)

-etwor0 administrators distribute a W($9algorithm9based 0ey 'or authori8ed users,

which pre"ents access by unauthori8ed users)


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!he protocol has authentications,deauthentication #this ser"ice is in"o0ed

whene"er an e.isting authentication is to beterminated%, and pri"acy pro"isions ;K EK)

Authentication #and deauthentication%ser"ices are used 'or establishing identity o'a station)

!he standard does not speci'y any particularauthentication scheme)


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$ri"acy ser"ices are used to pre"ent the

content o' messages 'rom being read by

other than intended recipients EK)


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Bluetooth

!his is a wireless communications protocol,

which was originally started by (ricsson)

5uic0ly became adopted by a consortium o'companies in the computer industry)

!he consortium grew 'rom a 'ew companies

to thousands including all o' the ma7orcompanies in the industry)


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It is designed to establish and maintain

connections between computing de"ices,

and electronic e5uipment, such ascomputers, $6A3s, cell phones, and so on,

wirelessly a"oiding the need 'or wires)

It is intended to wor0 in a close pro.imityen"ironment, such as homes, o''ices,

classrooms, hospitals, airports, etc)


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Connections are established using

designated masterandslavenodes)

It usesprofiles'or di''erent de"ices, whichcharacteri8e the applications, synchronous

connection9oriented #SCO% 'or data, and

asynchronous connectionless #AC&% lin0s'or "oice, which are multiple.ed on the

same lin0)


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re5uency9hopping spread spectrum with a high

;sec rate is used to reduce inter'erence,

and pro"ide low power, low cost radiocommunications)

It operates in the ISM band at ?)@ */8 with a

transmission power o' ; to ;== mW and a range

o' ;= to ;== meters, and a ma.imum bit rate o' ;Mbps, and an e''ecti"e data trans'er rate o' ?;

bps)


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1p to D de"ices can communicate in a

$iconet with one de"ice acting as the master

and the other de"ices as sla"es) Se"eral$iconet in one area can 'orm a HScatternet

in which all nodes use the same 're5uency

range with each H$iconet using a di''erenthop se5uence)


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!he bluetooth baseband speci'ication

de'ines a 'acility 'or lin0 security between

any two Bluetooth de"ices, consisting o' the'ollowing elements EK:

- At!entication

- Encry"tion #"ri$acy%

- &ey mana'ement and sa'e.


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!he security algorithms use 'our parameters:

+Unit address: !he @D9bit de"ice address, which

is publicly 0nown)+Secret at!entication (ey: A secret ;?D9bit 0ey)

+Secret Pri$acy (ey: A secret 0ey o' length 'rom

@ to ;?D bits)


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+)andom nmber: A ;?D9bit random number

deri"ed 'rom a pseudorandom generation

algorithm e.ecuted in the Bluetooth unit) !he two secret 0eys are generated and

con'igured with the unit and are not

disclosed)


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!he authentication process is used to

pro"ide "eri'ication o' the claimed identity

o' one o' the two Bluetooth de"icesin"ol"ed in an e.change)

Authentication is done by "eri'ying that the

two de"ices share the same precon'iguredauthentication 0ey)


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(ncryption o' pac0et payload can be used to

protect user in'ormation) !he access code

and the pac0et header are ne"er encrypted) !he encryption is done using an encryption

algorithm 0nown as (=EK) or each pac0et

transmission, a new encryption 0ey isgenerated)


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!he algorithm generates a one9time payload

0ey by combining in a comple. 'ashion a

random number, which is sent to the sla"e,the masterLs address, the current cloc0 "alue

and a shared secret 0ey) Because the cloc0

"alue changes 'or each encryption, adi''erent encryption 0ey is used each time,

enhancing security)


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Mobile I$

It is used to enable computers to maintainInternet connecti"ity while mo"ing 'romone Internet attachment point to another)

It uses the concept o' home and 'oreignnetwor0s and home and 'oreign agents)

Messages intended 'or a certain node, which

are sent to its home networ0, are 'orwardedto a care o' address to the mobile node at the'oreign networ0 where it is registered

pre"iously when the mo"e was detected)


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!he 'orwarding process uses datagram9

tunneling and encapsulation options, which

include I$9within9I$, minimal9encapsulation,

or *eneric routing encapsulation #*(% EK)

Mobile I$ has security 'eatures, which are

essential to its operation) !his is because a

wide "ariety o' attac0s could be used by anunauthori8ed user to access in'ormation o'

another user)


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It uses message authentication, registrationre5uest and reply contain authenticatione.tensions with security parameter inde.

#S$I% and authenticator) Authentication procedures are carried out to

secure mobile9home #mobile node>homecommunication%, mobile9'oreign #mobilenode>'oreign agent communications%, and'oreign9home #'oreign agent>home agentcommunications%)

Wireless A""lication Protocol


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Wireless A""lication Protocol

#WAP%

!his is an open standard, which pro"ides mobile

users o' wireless terminals such as wireless

phones, pagers, and $6A3s access to telephony

and in'ormation ser"ices EK) It is designed to wor0 with all wireless networ0

technologies such as *SM, C6MA, and !6MA)

It is based on e.isting Internet standards such as

I$, M&, /!M&, and /!!$ EK ;=K FK ;?K)


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!he WA$ 'orum is an industry association o' o"er

== members Hthat has de"eloped the de9'acto

world standard 'or wireless in'ormation and

telephony ser"ices on digital mobile phones and

other wireless terminals ;


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1sers are able to access e9commerce sites

'rom new wireless de"ices such as $6As

and mobile phones)


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*!e WAP S"eci+ication:

WA$ de'ines an open, standard architecture,

and a set o' protocols 'or the

implementation o' wireless access to theInternet)

!he WA$ speci'ications include ;@K EK:


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An ,M-ty"e mar(" lan'a'e Wireless

Mar(" an'a'e #WM%: It has te.t and

image support with 'ormatting layout and

commands)

6ec0>card organi8ational metaphor #documents

subdi"ided into cards which speci'y one or more

units o' interaction%, and support 'or na"igationamong cards and dec0s)


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A sample o' WM& code, consider the 'ollowing simpledec0 with one card ?=K)

Nwml

Ncard idP3card;3

Np

/ello WA$ World)

N>p

N>card N>wml


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!he tags Nwml, Ncard, and Np enclose the dec0,

card, and paragraph, respecti"ely) When a wireless

de"ice recei"es this code, it will display the message

H/ello WA$ World on the terminal3s screen)

!he boo0 in EK has a table with all o' WM& tags,

which are di"ided into eight 'unctional groups: 6ec0

Structure, Content, ormatting, 1ser Input,

4ariables, !as0s, and !as0>("ent Bindings) e'er toEK ;?K 'or more in'ormation on the WM& language)


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A /microbroser s"eci+ication: It de'ines

how WM& and WM&Scripts are determined in

the wireless de"ice) A li'!tei'!t "rotocol stac(: Wireless Session

$rotocol is e5ui"alent to /!!$ in a compressed

'ormat) 6esigned to minimi8e bandwidth use

allowing di''erent wireless networ0s, with"arying bandwidth capacities, to run WA$

applications)


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rameor( +or Wireless *ele"!ony

A""lications #W*A%: It pro"ides access to

traditional telephony ser"ices #such as Callorwarding% through WM&Scripts)

Pro$isionin':It allows Ser"ice $ro"iders to

recon'igure mobile de"ices remotely usingShort Messaging System #SMS%, which is a

*SM standard ;K)


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Com"onents o+ t!e WAP

Arc!itectre !he WA$ model consists o' three elements:

the client, gateway, and original ser"er) !his

is shown in 'igure ;) !he gateway ser"es as a pro.y, which

connects the wireless de"ice>s to the original

ser"er) /!!$ is used to communicate between the

gateway and the original ser"er)


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!he WA$ gateway per'orms 'unctions, which are spared

'rom the relati"ely less capable processor in the wireless

de"ices)

It pro"ides 6-S ser"ice, con"erts between the WA$

protocol stac0 #protocols that ha"e been optimi8ed 'or

low bandwidth, low power consumption, limited screen

si8ed, and limited storage% and the traditional WWWstac0 which includes /!!$ and !C$>I$)

encodes>decodes in'ormation 'rom the wired web to

more compact 'orm)


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which is more easily digested and displayed

by the more limited wireless de"ice)

!his reduces the amount o' datacommunicated wirelessly)

!he gateway also reduces communication

o"erhead and latency by caching recentlyre5uested web pages and in'ormation)


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:igure ; + !he WA$ $rogramming Model)

Client Original Ser"er

WA( user agent

*ateway

(ncoders and

6ecoders

Content

C*IScripts, etc)

esponse #content%(ncoded response

e5uests(ncoded re5uests


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WA$ speci'ications ha"e se"eral

components to pro"ide secure

communications) !hese components include the W!&S

protocol, WA$ identity module #WIM%

smart cards 'or storing user certi'icates, and'unctions such as Crypto)sign!e.t#%, which

is used 'or signing o' WA$ transactions)


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As shown in 'igure ?, the WA$ $rotocolStac0 is a layered architecture whichconsists o' se"eral protocol layers)

We will brie'ly describe each o' the layersand 'ocus on the the W!$ and W!&S layersin this paper)

On top is the Wireless Mar0up &anguage#WM&% #described later%, and WM&Scriptlayer, which is a scripting language withsimilarities to Ja"aScript)


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Below WM& and WM&Script is the

Wireless Application (n"ironment #WA(%

layer, which speci'ies an application'ramewor0 'or wireless de"ices such as

mobile phone, pagers, and $6As)

WA( consists o' tools and 'ormats that aredesigned to ease the tas0 o' de"eloping

applications and de"ices supported by WA$)

Wireless Mar0up &anguage #WM&% WM&Script


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Wireless Application (n"ironment #WA(%

Wireless !ransaction $rotocol #W!$%

Wireless Session $rotocol #WS$%

Wireless !ransport &ayer Security #W!&S%

p g g # % p

Wireless 6atagram $rotocol #W6$%

16$

*SM

I$

69AM$S IS9F E* Bluetooth

igure ? + WA$ $rotocol Stac0)


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!he WA( layer is 'ollowed by the Wireless Session$rotocol #WS$%)

WS$ pro"ides applications with an inter'ace 'or two

session ser"ices connection9oriented operating o"er

the Wireless !ransport $rotocol #W!$% #comparableto !C$ on the in wired networ0s% and connectionless

operating o"er the unreliable transport protocol called

Wireless 6atagram $rotocol #W6$% #comparable to

16$ in wired networ0s%)


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Basically, WS$ is based on /!!$ with some

modi'ications and additions to optimi8e its use

o"er wireless lin0s)

Below the WS$ layer, resides the Wireless

!ransaction $rotocol #W!$%, which will be

described later)

!hen below W!$, resides the Wireless !ransport&ayer Security #W!&S%, which will also be

discussed later)


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Below the W!&S layer, 'ollows theWireless 6atagram $rotocol #W6$%, which

in turn operates on top o' the a number o'

bearer ser"ice pro"iders such as *SM, 69AM$S, IS9F, E*, Bluetooth, etc)

We will only concentrate on the W!$ and

W!&S layers in this presentation)


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Wireless *ransaction Protocol

#W*P% W!$ manages transactions by con"eying

re5uests and responses between a user agent

#such as a WA$ browser% and an application

ser"er 'or such acti"ities as browsing and e9

commerce transactions EK)

It pro"ides reliable transport ser"ices without the

undesirable o"erhead o' !C$, which is thetransport layer protocol, used in wired networ0s)


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!his results in a lightweight protocol more

suitable 'or implementation in Hthin clients

#such as wireless>mobile de"ices% and o"erlow9bandwidth wireless lin0s)

It includes the 'ollowing 'eatures:

+Optional user9to9user reliability: W!$ user triggers

the con'irmation o' each recei"ed message)

+Optional out9o'9band data on ac0nowledgments)


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+$61 concatenation and delayed

ac0nowledgment to reduce the number o'

messages sent)

+Asynchronous transactions)

+!hree classes o' transaction ser"ices to pro"ide:

unreliable datagram ser"ice, reliable datagram

ser"ice, and re5uest>response transactionser"ice and support the e.ecution o' multiple

transactions during one WS$ session)


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*!e Wireless *rans"ort ayer

Secrity #W*S% Protocol !he WA$ protocol stac0 includes security

'eatures in its Wireless !ransport &ayer

Security #W!&S% layer, which is directlybelow the Wireless !ransaction $rotocol

#W!$%)


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W!&S/andsha0e

$rotocol

W!&S Alert

$rotocolW!$

W!&S ecord $rotocol

W!&S ChangeCipher Spec

$rotocol

:igure E + W!&S $rotocol Stac0

W6$ or 16$>I$


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Security o' WA$ transactions is achie"ed using the

W!&S protocol ;DK EK)

!he W!&S protocol pro"ides entity authentication,data con'identiality, and data integrity)

It is based on the I(! SS&>!&S protocols ;=K

;FK) W!&S pro"ides security 'or communications

between the WA$ wireless de"ice and the WA$*ateway)


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As shown in 'igure E, the W!&S $rotocol

Stac0 includes W!&S handsha0e protocol,

W!&S Change Cipher Spec $rotocol,W!&S Alert $rotocol, and W!$ at the top)

Below resides the W!&S ecord $rotocol,

which in turn lays on top o' the W6$ or

16$>I$ layer)


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!he 'unction o' the W!&S ecord $rotocol is to ta0e

the user data 'rom the ne.t higher layer #W!$, W!&S

handsha0e protocol, W!&S Alert $rotocol, W!&Schange cipher spec protocol% and encapsulates the data

in a $61 #$rotocol 6ata 1nit% EK)

!he $61 contains the data in a compressed, and

encrypted 'orm with a W!&S record header appendedto it) (ncryption is done using a symmetric encryption

algorithm) !he allowable encryption algorithms are

6(S, triple 6(S, C and I6(A ;EK)


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!he W!&S protocol has three di''erentclasses o' ser"ice ;=K:

Class 1: !his class implements

unauthenticated 6i''ie9/ellman 0ey e.changeto establish the session 0ey) (arly WA$ de"ices

only implement this le"el, which is insu''icient

and should not be used 'or e9commerce

transactions ?;K)


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+Class 2: !his class en'orces ser"er side

authentication using public 0ey certi'icates

similar to SS&>!&S protocol) !he WA$ *ateway

uses a W!&S certi'icate, which is a particular

'orm o' )=F certi'icate compressed to sa"e

bandwidth) !his le"el is used in currently

a"ailable de"ices, which are being used in se"eral

read9only access and in9economy ban0ing

applications in (urope and the 1 ??K)


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+Class 3: 1sing this class, clients are able to

authenticate using client side certi'icates, which

are regular )=F 'ormat) !hese certi'icates

can be stored either on the client or on a

publicly accessible ser"er with a pointer to the

certi'icate stored in the wireless de"ice) !his

class is beginning to be used in wireless phones?EK)


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-o0ia, $- Mobile, and Interpay -ederland ha"e

success'ully tested 'inancial transaction on a mobile

networ0 ?EK, based on WIM technology, which is a

part o' the WA$ ;)? #Wireless Application $rotocol%speci'ication)

With this real time payment solution, a mobile

telecommunications networ0 operator, a mobile phone

and in'rastructure manu'acturer and a paymentprocessor ha"e made impro"ement in security 'or

mobile commerce transactions)


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!he solution is based on WIM #Wireless Identity

Module%, which is a mobile Internet technology

enabling more secure transactions)

-on9repudiation o' transactions is ensured by a

digital signature) In practice, this means users can

per'orm transactions sa'ely using a single $I-9code)

In addition, built9in security elements in the terminaland networ0 ensure more secure and reliable

transactions)


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Class E security ser"ices, which are in the process

o' being o''ered by di''erent wireless de"icemanu'acturers such as -o0ia and Motorola, are

e.pected to allow ban0ing institutions to enhance

their current wireless e9commerce ser"ices to

allow Hout9o'9economy transactions)


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As shown in 'igure E, the W!&S protocol stac0 alsocontains the 'ollowing protocols:

*!e C!an'e Ci"!er S"ec Protocol:

+!he cipher spec is associated with the current transaction)

+It speci'ies the encryption algorithm, the hash algorithm

used as part o' /MAC, and cryptographic attributes, such

as MAC code si8e) !his protocol is used in the process

o' establishing the cipher suite used 'or subse5uentcommunications during a session)


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*!e Alert Protocol:

+1sed to con"ey W!&S9related alerts to the peer entity)

Alert messages are compressed and encrypted as well)

*!e 3ands!a(e Protocol in t!e W*S:

+ It allows the ser"er and client to authenticate each otherand to negotiate an encryption and MAC algorithm and

cryptographic 0eys to be used to protect the data sent in

the W!&S record) !he /andsha0e protocol is used to

establish the security pro"isions be'ore any application

data is e.changed EK)

Some Additional Isses


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Concernin' WAP Secrity:

esearch has identi'ied some additional

issues regarding the security o' WA$ based

systems) !he 'ollowing are some o' theseissues)


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Abot Maintenance o+ t!e WAP 4ateay:

+!he WA$ *ateway can be maintained by the

Wireless Ser"ice $ro"ider #WS$% or by the(nterprise #on the ser"er side%)

+I' the WS$ maintains the WA$ gateway howe"er,

some literature ;=K re'ers to the presence o' a

security Hgap caused by the ending o' theWireless !ransport &ayer Security #W!&S%

session at the *ateway)


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+!he data is temporarily in clear te.t on the

*ateway until it is re9encrypted under the SS&

session established with the (nterprise3s web

ser"er)

+In such cases, the WA$ *ateway should be

maintained at the (nterprise) A more detailed

discussion o' this issue is presented in ;=K)


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*!e WAP Identity Modle #WIM%:+-ew generation o' WA$ phones will pro"ide

WIM to 'acilitate client side authentication?@K) WIM is used to implement W!&S

protocol Class E 'unctionality)

+It has embedded support 'or public 0ey

cryptography) With the WIM implementation,SA ?;K is mandatory and (lliptic Cur"eCryptography ?;K is optional)


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+Smart card is one possible implementation o' WIM)

It could be a part o' the SIM #subscriber identity

module% card in a cellular phone #in *SM ;K% or

an separate smart card #WIM card%)+A combination o' SIM9WIM card is typically called

a SWIM card) !he WIM card would be con'igured

by the manu'acturer with two sets o' pri"ate9public

0ey pairs #one 'or signing and one 'orauthentication%, and two manu'acturer3s certi'icates)


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+All W!&S sessions established through a WIM

and a WA$ *ateway will use the same public0eys 'or initial session negotiations)

+A WIM is able to store a number o' certi'icatesor user certi'icate re'erences, such as a 1&9

based re'erence)

+A user will be re5uired to register a certi'icateat each (nterprise #such as a Ban0, etc)%)

+!he WIM must be tamper resistant to ma0e itnot 'easible to e.tract or change in'ormation inthe module, because it contains user pri"ate0eys, which ne"er lea"e the WIM)

User Identi+ication and


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User Identi+ication and

At!entication in WAP !he type o' user identi'ication and authenticationpossible in WA$ di''ers with the W!&S class o'ser"ice used)

1sername>password identi'ication and authenticationcan be used with WM& 'orms e.changed betweenthe ser"er and the wireless de"ice)

It is also possible to ha"e client9side identi'ication

and authentication based on the public>pri"ate 0eypair that is hardcoded on the WIM card and boundwith the user3s name in their certi'icate)


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5on-re"diation in WAP:

+It re5uires client side certi'icates that bind the

user3s signing 0ey with their name)+!he WA$ browser, on the WA$ de"ice,

pro"ides WM&Script 'unction,

Crypto)sign!e.t#% ?K, which achie"es this

purpose using di''erent scenarios depending onthe implementation)

Some )esearc! and tre


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6irections in Wireless Systems

Secrity W!at is Secre Soc(ets ayer #SS% 7

+SS& is the most widely deployed and used

security protocol in the world)+(ssentially e"ery commercial Web browser and

ser"er supports secure Web transactions usingSS&)

+Qou are almost certainly using SS& e"ery timeyou buy online using Hsecure Web pages ;EK)Currently, tens o' billions o' dollars worth o'SS& transactions occur per year)


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+SS& is mostly used 'or securing Web tra''ictransactions, howe"er, it is a general protocol

suitable 'or securing many other types o' tra''ic)

+In addition to the World Wide Web, SS& and its

successor, !ransport &ayer Security #!&S%, are usedin other popular applications such as ile !rans'er

$rotocol #!$%, remote ob7ect access #MI,

COBA, IIO$%, e9mail transmission #SM!$%,

remote terminal ser"ice #!elnet% and directory access#&6A$% to secure their transactions)


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+As will be shown later in this paper, SS& is

currently being used in di''erent stages o' the

transaction communications between wireless

de"ices and the wired in'rastructure)

U i SS i Wi l


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n Usin' SS in Wireless

Commnications 6ue to the percei"ed relati"e decrease in capabilities o'wireless de"ice C$1s and lower bandwidth

capabilities o' wireless channels, there is a dri"e away

'rom SS& and toward security architectures designed'or wireless transactions that lac0 end9to9end security)

/owe"er, some literature


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*!e 6e$elo"ment o+ i'!tei'!t Secrity

Mec!anisms +or Wireless Mltimedia

*ra++ic *ransmission

In addition to the abo"e protocols, and

architectures, research is being done in order

to design Hlightweight encryptionalgorithms 'or M$(* "ideo transmission)

In K, researchers propose to pro"ide

encryption o' "ideo data while increasingthe decodability o' the "ideo stream in the

presence o' errors)


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!hese algorithm e.plore the predictable

relationship between the I, $, and B9'rames

o' compressed "ideo, and decrease thee.pected number o' bit errors le't in the

data a'ter encoding)

or more in'ormation on these techni5uesthe reader is re'erred to K)

n Secrity o+ Mobile P!one


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Commnications

urthermore, some research is being done on thesecurity management planning 'or

telecommunication systems, with 'ocus on intrusion

detection and cloning mobile phone problems)

In DK, researchers discuss mobile phone networ0security management planning with its "arious

aspects such as access control, con'identiality,

authentication, non9repudiation, and integrity o'

data communications)


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!he research also addresses intrusiondetection systems design 'or mobile phone

communications)

Intrusion can be classi'ied as: #i% misuseintrusion, i)e), well de'ined attac0s against

0nown system "ulnerabilitiesR and #ii%

anomaly intrusion, i)e), acti"ities based on

de"iation 'rom normal system usage patterns)


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Intrusion detection systems are considered

e''ecti"e security tools to de'end against such

attac0s DK)

esearch shows that current so'tware in mobile

phone systems

+#i% do not ha"e an e''icient scheme to "eri'y i' a call is

out o' the client patterns o' communications #in most o'these systems human sta''s are used to identi'y cloned

phones and warn their clients in such situations%R


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+#ii% ha"e no e''icient ways to control and

identi'y the impostorR and

+#iii% use an He.perimental satis'action to pro"e

the correctness o' their security mechanisms)

Better, and more automated techni5ues 'or

security management and identi'ication o'

'rauds, and impostors using cloned mobilephones are needed)


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+Some research uses neural networ0 techni5ues to

classi'y phone users into groups according to their

past>current pro'iles) It is then relati"ely easy to

determine whether a call was made by the actualsubscriber, or an impostor>intruder DK) Such

technology can be "ery e''ecti"e in battling and

pre"enting cloning o' mobile de"ices and

conse5uently result is substantial sa"ings and moresecurity and pri"acy 'or wireless ser"ice pro"iders

and their customers)


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Concldin' )emar(s

Wireless systems are 5uic0ly becoming an

important and increasingly essential part o'

our e"ery day acti"ities) !hey pro"ide unlimited potential 'or

con"enience, more independence,

portability, a"ailability, instantaneous, andubi5uitous connecti"ity where"er we go)


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!hey promise great 'inancial gains to thecompanies that in"est in the de"elopment,mar0eting, sales, leasing, maintenance anduse o' these 5uic0ly e"ol"ing andincreasingly smaller, easily portable, andprogressi"ely more intelligent products)

Wireless de"ices are e.pected to hold andcommunicate a large amount o' data andin'ormation about e"ery aspect o' our li"es)


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!hey are also e.pected to carry outnumerous, important, and sensiti"e 'inancial

transactions, which can only be done in a

relati"ely secure and well9protecteden"ironment)

!his protection and security is re5uired to

"arying degrees depending on theapplication in"ol"ed)


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!he authors in


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Some e.periments show that SS&, which is a well9

tested and e"aluated technology, is able to be

practically and e''iciently used in current and the

'uture wireless and portable de"ices)

!his is particularly the case considering that the

capabilities o' the C$13s, memory, and bandwidth

o' these de"ices is signi'icantly impro"ing e"eryday)


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!his e''iciency is achie"ed by care'ully selecting andimplementing a subset o' the protocol3s many 'eatures

#ull "ersus abbre"iated SS& handsha0e per e.ample,

etc)% to ensure acceptable per'ormance and

compatibility with a large installed base o' secure webser"ers)

All this can be done while maintaining a small memory

'ootprint) !his is in concert with the concept stated by

the Ice /oc0ey &egend, Wayne *ret8s0y who said:H6on3t s0ate to the puc0R s0ate to where it3s going


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Wireless systems3 'ull potential and promise canonly be reali8ed i' the security aspects o' these

systems are well considered)

$roper design and implementation must be done

according to sound security principles, which

must be employed throughout the analysis,

design, implementation, testing, and maintenance

phases o' these products and systems)


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6uring their initial inception and the 'irst years o' their

introduction to the mar0et, security was not a ma7or concern or

design ob7ecti"e) /owe"er, this is 5uic0ly changing to ta0e a proper high priority

in the design and implementation o' wireless systems)

Considerable amount o' research has been and is being done to

pro"ide 'or more secure wireless systems at e"ery le"el o' theirarchitecture)

!his research is needed to pro"ide security mechanisms at the

le"el o' the portable de"ice as well as the supporting wired and

wireless system in'rastructures)


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)e+erences;) Sandra ay Miller, Hacing the Challenge o' Wireless Security, I((( Computer) July ?==;)

$ages: ;


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F) 6) 4an !hanh, HSecurity issues in mobile ecommerce, 6atabase and (.pert SystemsApplications, ?===) $roceedings) ;;th International Wor0shop on, ?===) $age#s%: @;? 9@?

;=) $) Ashley, /) /inton, M) 4andenwau"er, HWired "ersus Wireless Security: !he Internet, WA$and imode 'or (9commerce, Computer Society Applications Con'erence, ?==;) ACSAC?==;) $roceedings ;thAnnual, ?==;) $age#s%: ?F>www)gsmworld)com

;D) Wireless Application $rotocol Wireless !ransport &ayer Security Speci'ication #W!&S%,http:>>www)wap'orum)org>tech>documents>WA$9;FF9W!&S9?====?;D9a)pd')
http://www.wapforum.org/http://www.wapforum.org/http://www.wapforum.org/http://www.wapforum.org/


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;F) !) 6ier0s, C) Allen, !he !&S $rotocol + 4ersion ;)=, C ??@

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