2154 A Model of Information Security Governance for E-Business challenge. Information Management & Computer Security, 8(3), 154-157. Mann, D. (2004). A life-cycle approach to risk management. Retrieved October 10, 2004, from http://www.computerworld.com/securitytop- ics/security/ McAdams, A. (2004). Security and risk manage- ment: A fundamental business issue. Information Management Journal, 38(4), 36. McKay, J., & Marshall, P. (2004). Strategic man- agement of eBusiness. Milton, Queensland, AUS: John Wiley & Sons. National Cyber Security Partnership (2004). In- formation security governance - A call to action. Retrieved October 26, 2004, from http://www. cyberpartnership.org/InfoSecGov4_04.pdf Rodger, J., Yen, D., & Chou, D. (2002). Develop- ing e-business: A strategic approach. Informa- tion Management & Computer Security, 10(4), 184-192. Standards Australia. (2004). Corporate gover- nance of information and communication technol- ogy - Draft for public comment. Retrieved April 20, 2004, from http://www.standards.com.au Wright, A. (2001). Controlling risks of E-com- merce Content. Computers & Security, 20(2), 147-154. Zimmerman, J. W. (2002, November). Is your company at risk? Lessons from Enron ® . USA TODAY ® , 1, 27-29. TRADMARK NOTICE •ITGI ® is a registered trademark of Informa- tion Systems Audit and Control Association, Inc. / IT Governance Institute (ITGI). •USA TODAY ® is a registered trademark of Gannett Co. Inc. •Business Week ® is a registered trademark of the McGraw-Hill Companies, Inc. •Enron ® is a registered trademark of Enron Corp. This work was previously published in Enterprise Information Systems Assurance and Systems Security: Managerial and Technical Issues, edited by M. Warkentin, pp. 1-15, copyright 2006 by IGI Publishing (an imprint of IGI Global). 2155 Copyright © 2009, IGI Global, distributing in print or electronic forms without written permission of IGI Global is prohibited. Chapter 7.13 Wireless LAN Setup and Security Loopholes Biju Issac Swinburne University of Technology, Malaysia Lawan A. Mohammed Swinburne University of Technology, Malaysia ABSTRACT This chapter gives a practical overview of the brief implementation details of the IEEE802.11 wireless LAN and the security vulnerabilities involved in VXFK QHWZRUNV 6SHFL¿FDOO\ LW GLVFXVVHV DERXW the implementation of EAP authentication using RADIUS server with WEP encryption options. The chapter also touches on the ageing WEP and the cracking process, along with the current TKIP and CCMP mechanisms. War driving and other security attacks on wireless networks are DOVREULHÀ\FRYHUHG7KHFKDSWHUFRQFOXGHVZLWK practical security recommendations that can keep intruders at bay. The authors hope that any reader would thus be well informed on the security vul- nerabilities and the precautions that are associated with 802.11 wireless networks. INTRODUCTION Over the recent past, the world has increasingly becoming mobile. As mobile computing is get- ting more popular each day, the use of wireless local area network (WLAN) is becoming ever more relevant. If we are connected to a wired network, our mobility is undoubtedly affected. From public hotspots in coffee shops to secure WLAN in organizations, the world is moving to ubiquitous and seamless computing environments. IEEE 802.11 has been one of the most successful wireless technologies, and this chapter would be focusing more on this technology. 0RELOLW\DQGÀH[LELOLW\KDVEHHQWKHNH\QRWH advantages of wireless networks in general. Users can roam around freely without any inter- ruption to their connection. Flexibility comes in as users can get connected through simple steps of authentication without the hassle of running 2156 Wireless LAN Setup and Security Loopholes cables. Also, compared to the wired network, wireless network installation costs are minimal as the number of interface hardware is minimal. Radio spectrum is the key resource, and the wireless devices are set to operate in a certain frequency band. 802.11 networks operate in the 2.4 GHz ISM band, which are generally license free bands. The more common 802.11b devices operate in the S-band ISM. In the next sections, we will be explaining the wireless LAN basic setup and implementa- tion, WEP encryption schemes and others, EAP authentication through RADIUS server and its brief implementation, WEP cracking procedure, war driving, 802.11b vulnerabilities with secu- ULW\DWWDFNVDQG¿QDOO\FRQFOXGLQJZLWK:/$1 security safeguards. WIRELESS LAN NETWORK AND TECHNOLOGIES INVOLVED Network Infrastructure To form the wireless network, four generic types of WLAN devices are used. These are wireless station, access point (AP), wireless router, and wireless bridge. A wireless station can be a note- book or desktop computer with a wireless network card in it. Access points act like a 2-port bridge linking the wired infrastructure to the wireless infrastructure. It constructs a port-address table and operates by following the 3F rule: ÀRRG- ing, forwarding, and ¿OWHULQJ )ORRGLQJ LV WKH process of transmitting frames on all ports other than the port in which the frames were received. )RUZDUGLQJDQG¿OWHULQJLQYROYHWKHSURFHVVRI transmitting a frame based on the port-address mapping table in AP, so that only the needed port is used for transmission. Wireless routers are ac- cess points with routing capability that typically includes support for dynamic host control protocol (DHCP) and network address translation (NAT). To move the frames from one station to the other, WKHVWDQGDUGGH¿QHVDZLUHOHVVPHGLXP that supports two radio frequency (RF) physical layers and one infrared physical layer. RF layers are more popular now (Held, 2003, pp. 7-14). Modes of Operation IEEE802.11 WLAN can operate in two modes, namely ad hoc (or peer-to-peer) and infrastructure mode. These modes come under the basic service set (BSS), which is a coverage area of commu- nication that allows one station to communicate to the other. Ad hoc mode has WLAN stations or nodes communicating with one another without an access point to form an independent basic service set (IBSS). In contrast, infrastructure mode has WLAN nodes communicating with a central AP that is, in turn, linked to a wired LAN to form a basic service set. Here, the AP acts as a relay between wireless stations or between wired and wireless stations. A combination of many BSS with a backbone distribution system (normally ethernet) forms an extended service set (ESS). IEEE 802.11 Architecture and Standards 802.11 is a member of IEEE 802 family, which GH¿QHVWKHVSHFL¿FDWLRQVIRUORFDODUHDQHWZRUN WHFKQRORJLHV,(((VSHFL¿FDWLRQVDUHFHQWHUHG on the two lowest layers of OSI model, namely the physical layer and the data link layer. The base VSHFL¿FDWLRQLQFOXGHVWKH0$&OD\HU and two physical layers namely, the frequency hopping spread spectrum (FHSS) layer in the 2.4 GHz band, and the direct sequence spread spectrum (DSSS) layer. Later revisions to 802.11 added additional physical layers like high-rate direct-sequence layer (HR/DSSS) for 802.11b and orthogonal frequency division multiplexing (OFDM) layer for 802.11a. The different extensions to the 802.11 standard use the radio frequency band differently. Some of the popular 802.11 extensions are as follows: 2157 Wireless LAN Setup and Security Loopholes E ² VSHFL¿HV WKH XVH RI '666 DW 5.5 and 11 Mbps. The 802.11 products are quite popular with its voluminous production. 802.11a VSHFL¿HVWKHXVHRIDIUHTXHQF\PXOWLSOH[LQJ scheme called orthogonal frequency division multiplexing (OFDM), and it uses a physical layer standard that operates at data rates up to 54 Mbps. As high frequencies attenuate more, one needs more 802.11a access points compared to XVLQJEDFFHVVSRLQWVJVSHFL¿HVD high-speed extension to 802.11b that operates in 2.4 GHz frequency band using OFDM to obtain data rates up to 54 Mbps and as well as back- ward compatible with 802.11b devices. 802.11i recognizes the limitations of WEP and enhances ZLUHOHVVVHFXULW\,WGH¿QHVWZRQHZHQFU\SWLRQ methods as well as an authentication method. The two encryption methods designed to replace WEP include temporal key integrity protocol (TKIP) and advanced encryption standard (AES). The authentication is based on the port-based 802.1x DSSURDFKGH¿QHGE\ D S U LRU,(((V W D QG D UG2W KH U 802.11 extensions include 802.11c (focuses on MAC bridges), 802.11d (focuses on worldwide use of WLAN with operation at different power levels), 802.11e (focuses on quality of service), 802.11f (focuses on access point interoperability) and 802.11h (focuses on addressing interference problems when used with other communication equipments) (Held, 2003, pp. 27-32). Joining an Existing Cell There are three stages that a station has to go through to get connected to an existing cell, namely scanning, authentication, and associa- tion. When a station wants to access an existing BSS (either after power up, sleep mode, or just entering the BSS area), the station needs to get synchronization information from the access point (or from the other stations when in ad-hoc mode). The station can get this information by one of the two modes: passive scanning and active scanning. In passive scanning mode, the station just waits to receive a beacon frame from the AP and records information from it. The beacon frame is a periodic frame sent by the AP with synchronization information. This mode can save battery power, as it does not require transmitting. In active scanning modeWKHVWDWLRQWULHVWR¿QG an access point by transmitting probe request frames, and waiting for probe response frames from the AP. This is more assertive in nature. It follows the simple process as follows. Firstly, it moves to a channel to look for an incoming frame. If incoming frame is detected, the channel can be probed. Secondly, it tries to gain access to the medium by sending a probe request frame. 7KLUGO\LWZDLWVIRUDSUHGH¿QHGWLPHWRORRNIRU any probe response frame and if unsuccessful, to move to the next channel. The second stage is authentication. It is nec- essary, when the stations try to communicate to one another, to prove their identity. Two major DSSURDFKHVWKDWDUHVSHFL¿HGLQDUHRSHQ system authentication and shared-key authentica- tion. In open system authentication, the access point accepts the mobile station implicitly without YHUL¿FDWLRQDQGLWLVHVVHQWLDOO\DWZRIUDPHH[- change communication. In shared key authentica- tion, WEP (wired equivalent privacy) encryption has to be enabled. It requires that a shared key be distributed to stations before attempting to do authentication. The shared-key authentication exchange consists of four management frame exchanges that include a challenge-response approach. The third stage is association, and this is restricted to infrastructure networks only. Once the authentication is completed, stations can as- sociate with an access point so that it can gain full access to the network. Exchange of data can only be performed after an association is established. The association process is a two-step process further involving three stages: unauthenticated- unassociated stage, authenticated-unassociated stage, and authenticated-associated stage. 2158 Wireless LAN Setup and Security Loopholes All access points (AP) transmit a beacon man- DJHPHQWIUDPHDW¿[HGLQWHUYDOV$ZLUHOHVVFOLHQW that wants to associate with an access point and join a BSS listens for beacon messages that con- tain information regarding VHUYLFHVHWLGHQWL¿HU (SSID) or network names to determine the access points within range. After identifying which AP to associate with, the client and AP will perform mutual authentication by exchanging several management frames as part of the process. After getting authenticated, the client moves to second stage and then to third stage. To get associated, the client needs to send an association request frame, and the AP needs to respond with an as- sociation response frame (Arbaugh, Shankar, & Wan, 2001). Association helps to locate the position of the mobile station, so that frames destined for that station can be forwarded to the right access point. Once the association is complete, the access point would register the mobile station on the network. This is done by sending gratuitous ARP (address resolution protocol) packets, so that the mobile station’s MAC address is mapped with the switch port connected to the access point. Reassociation is a procedure of moving the association from an old access point to a new one. It is also used to rejoin a network if the station leaves the cell and returns later to the same access point. WLAN Association Table on CISCO Access Point Figure 1 shows the details of a wireless node that LVFRQQHFWHGLQDZLUHOHVV/$1FHOO7KH¿JXUH shows the details of CISCO Aironet 320 series AP and another client connected within the cell. This is a very simple wireless connection between a station and AP, with no encryption enabled and no authentication enabled. The forthcoming section shows how to make the setup more secure. ENCRYPTION MECHANISMS IN IEEE 802.11B AND 802.11I As WLAN data signals are transmitted over the air, it makes them vulnerable to eavesdropping. Figure 1. CISCO access point association table screen 2159 Wireless LAN Setup and Security Loopholes 7KXV FRQ¿GHQWLDOLW\ RI WUDQVPLWWHG GDWD PXVW be protected, at any cost, by means of encryp- WLRQ7KH,(((EVWDQGDUGGH¿QHVVXFKD mechanism, known as wired equivalent privacy, which uses the RC4 encryption method. However, various security researchers have found numerous ÀDZVLQ:(3GHVLJQ7KHPRVWGHYDVWDWLQJQHZV broke out in 2001, which explained that the WEP encryption key can be recovered when enough packets are captured. Since then, this attack has EHHQYHUL¿HGE\VHYHUDORWKHUVDQGLQIDFWIUHH software is available for download that allows for capturing WEP packets and using those to crack the key. Wired Equivalent Privacy Wired equivalent privacy is a standard encryp- tion for wireless networking. It is a user authen- tication and data encryption system from IEEE 802.11 that is used to overcome security threats. Basically, WEP provides security to WLAN by encrypting the information transmitted over the air, so that only the receivers who have the correct encryption key can decrypt the information. If a user activates WEP, the network interface card encrypts the payload (frame body and CRC) of each 802.11 frame, before transmission, using an RC4 stream cipher provided by RSA security. The receiving station, such as an access point, performs decryption upon arrival of the frame. As a result, 802.11 WEP only encrypts data be- tween 802.11 stations. Once the frame enters the wired side of the network, such as between access points, WEP no longer applies. As part of the encryption process, WEP prepares a key schedule ³VHHG´E\FRQFDWHQDWLQJWKHVKDUHGVHFUHWNH\ supplied by the user of the sending station with a randomly generated 24-bit initialization vector (IV). The IV lengthens the life of the secret key because the station can change the IV for each frame transmission. WEP inputs the resulting ”seed” into a pseudorandom number generator that produces a key stream equal to the length of the frame’s payload plus a 32-bit integrity check sum value (ICV). The ICV is a check sum that the receiving station eventually recalculates and compares with the one sent by the sending station to determine whether the transmitted data under- went any form of tampering while in transit. If the receiving station calculates an ICV that does not match the one found in the frame, then the UHFHLYLQJVWDWLRQFDQUHMHFWWKHIUDPHRUÀDJWKH user (Borisov, Goldberg, & Wagner, 2001). The WEP encryption process is shown as follows: 1. Plaintext (P) = Message (M) + Integrity Check Sum of Message (C(M)) 2. Keystream = RC4(v, k), where v is the IV and k is he shared key 3. Ciphertext (C) = Plaintext (P) Keystream 4. Transmitted Data = v + Ciphertext The decryption is done by using th reverse process as follows: 1. Ciphertext (C) Keystream Æ Plaintext (P) What is Wrong with WEP? WEP has been part of the 802.11 standard since LQLWLDOUDWL¿FDWLRQLQ6HSWHPEHU$WWKDWWLPH the 802.11 committee was aware of some WEP limitations; however, WEP was the best choice WRHQVXUHHI¿FLHQWLPSOHPHQWDWLRQVZRUOGZLGH Nevertheless, WEP has undergone much scrutiny and criticism over the past couple of years. WEP is vulnerable because of relatively short IVs and keys that remain static. The issues with WEP do not really have much to do with the RC4 encryp- t i o n a l g o r i t h m . W i t h o n l y 2 4 b i t s , W E P e v e n t u a l l y uses the same IV for different data packets. For a large busy network, this reoccurrence of IVs can happen within an hour or so. This results in the transmission of frames having key streams that are too similar. If a hacker collects enough frames based on the same IV, the individual 2160 Wireless LAN Setup and Security Loopholes can determine the shared values among them; for instance, the key stream or the shared secret key. This leads to the hacker decrypting any of the 802.11 frames. The static nature of the shared secret keys emphasizes this problem. 802.11 does not provide any functions that support the exchange of keys among stations. As a result, system administrators and users generally use the same keys for weeks, months, and even years. This gives mischievous culprits plenty of time to monitor and hack into WEP-enabled networks. Some vendors deploy dynamic key distribution VROXWLRQVEDVHGRQ[ZKLFKGH¿QLWHO\LP- proves the security of wireless LANs (Giller & Bulliard, 2004). 7KH PDMRU:(3GHVLJQÀDZVPD\EHVXP- marized as follows (Gast, 2002, pp. 93-96): • Manual key management is a big problem with WEP. The secret key has to be manu- ally distributed to the user community, and widely distributed secrets tend to leak out as time goes by. • When key streams are reused, stream ciphers are vulnerable to analysis. Two frames that use the same IV are almost certain to use the same secret key and key stream, and this problem is aggravated by the fact that some implementations do not even choose random IVs. There are cases where, when the card was inserted, the IV started off as zero, and incremented by one for each frame. By reusing initialization vectors, WEP enables an attacker to decrypt the encrypted data without ever learning the encryption key or even resorting to high-tech techniques. While often dismissed as too slow, a patient attacker can compromise the encryption of an entire network after only a few hours of data collection. • WEP provides no forgery protection. Even without knowing the encryption key, an adversary can change 802.11 packets in ar- bitrary and undetectable ways, deliver data to unauthorized parties, and masquerade as an authorized user. Even worse, an adversary can also learn more about an encryption key with forgery attacks than with strictly passive attacks. • WEP offers no protection against replays. An adversary can create forgeries, without changing any data in an existing packet, simply by recording WEP packets and then retransmitting later. Replay, a special type of forgery attack, can be used to derive information about the encryption key and the data it protects. • WEP misuses the RC4 encryption algorithm in a way that exposes the protocol to weak key attacks and public domain hacker tools like Aircrack, and many others exploit this weakness. An attacker can utilize the WEP IV to identify RC4 weak keys, and then use k n o w n p l a i n t e x t f r o m e a c h p a c k e t t o r e c o ve r the encryption key. • Decryption dictionaries, which consist of a large collection of frames encrypted with the same key streams, can be built because of infrequent rekeying. Since more frames with the same IV come in, chances of decrypting them are more, even if the key is not known or recovered. • WEP uses CRC for integrity check, en- crypted using RC4 key stream. From a cryptography view point, CRC is not secure I U R P D Q D W W D F N RII U D PH P R G L ¿FD W L R Q ZKH U H W KH D W W D F NH U PR G L ¿H VW K H I U D PH G D W D F R QW H Q W V as well as the CRC value. In view of these WEP shortcomings, the IEEE 802.11 Task Group i (TGi) is developing a new set of WLAN security protocols to form the future IEEE 802.11i standard. These include the temporal key integrity protocol (TKIP) and the counter mode with CBC-MAC protocol (CCMP). The TKIP is a short-term solution that will adapt existing WEP implementations to address the :(3ÀDZVZKLOHZDLWLQJIRU&&03WREHIXOO\ 2161 Wireless LAN Setup and Security Loopholes deployed. CCMP is a long-term solution that ZLOO QRW RQO\ DGGUHVV FXUUHQW :(3 ÀDZV EXW will include a new design incorporating the new advanced encryption standard (AES). The New 802.11i Standard The new security standard, 802.11i, which was FRQ¿UPHGDQGUDWL¿HGLQ-XQHHOLPLQDWHV all the weaknesses of WEP. It is divided into three main categories (Strand, 2004): 1. Temporary key integrity protocol (TKIP): This is, essentially, a short-term solution WKDW¿[HVDOO:(3ZHDNQHVVHV,WZRXOGEH compatible with old 802.11 devices, and it SURYLGHVLQWHJULW\DQGFRQ¿GHQWLDOLW\ 2. Counter mode with CBC-MAC protocol (CCMP): This is a new protocol designed with planning based on RFC 2610, which u s e s A E S a s c r y p t o g r a p h i c a l g o r i t h m . S i n c e this is more CPU intensive than RC4 (used in WEP and TKIP), new and improved 802.11 hardware may be required. Some drivers can implement CCMP in software. It provides LQWHJULW\DQGFRQ¿GHQWLDOLW\ 3. 802.1x port-based network access control: Either when using TKIP or CCMP, 802.1x is used as authentication. TKIP and CCMP will be explained in the fol- lowing sections. 802.1x is explained in detail in the section titled Radius Server and Authentica- tion Mechanisms. Temporary Key Integrity Protocol (TKIP) TKIP is part of a draft standard from the IEEE 802.11i working group. TKIP is an enhancement to WEP security. The TKIP algorithms are designed explicitly for implementation on legacy hardware, hopefully without unduly disrupting performance. TKIP adds four new algorithms to WEP (Cam- Winget, Housley, Wagner, & Walker, 2003): • A cryptographic message integrity code, called Michael, to defeat forgeries has been added. Michael is an MIC algorithm that calculates a keyed function of data at the transmitter; sends the resulting value as a CRC check or tag with the data to the receiver, where it recalculates the tag value; and compares the computed result with the tag accompanying the data. If the two values match, the receiver accepts the data as authentic. Otherwise, the receiver rejects the data as a forgery. • A new IV sequencing discipline to remove replay attacks has been added. TKIP extends the current WEP format to use a 48-bit sequence number, and associates the sequence number with the encryption key. TKIP mixes the sequence number into the encryption key and encrypts the MIC and the WEP ICV. This design translates replay attacks into ICV or MIC failures. • A per-packet key mixing function, to decor- relate the public IVs from weak keys is added. TKIP introduces a new per-packet encryption key construction, based on a mixing function. The mixing function takes the base key, transmitter MAC address, and packet sequence number as inputs, and outputs a new per-packet WEP key. To minimize computational requirements, the mixing function is split into two phases. 7KH¿UVWSKDVHXVHVDQRQOLQHDUVXEVWLWXWLRQ table, or S-box, to combine the base key, the transmitter MAC address, and the four most VLJQL¿FDQW RFWHWV RI WKH SDFNHW VHTXHQFH number to produce an intermediate value. The second phase mixes the intermediate YDOXHZLWKWKHWZROHDVWVLJQL¿FDQWRFWHWVRI the packet sequence number, and produces a per-packet key. 2162 Wireless LAN Setup and Security Loopholes • A rekeying mechanism is added to provide fresh encryption and integrity keys, undo- ing the threat of attacks stemming from key reuse. The IEEE 802.1x key management scheme provides fresh keys (Cam-Winget et al., 2003). Counter Mode with CBC-MAC Protocol (CCMP) CCMP (counter mode with cipher block chain- ing message authentication code protocol) is the preferred encryption protocol in the 802.11i standard. CCMP is based upon the CCM mode of the AES encryption algorithm. CCMP utilizes 128-bit keys, with a 48-bit initialization vector (IV) for replay detection. The counter mode (CM) component of CCMP is the algorithm providing data privacy. The cipher block chaining message authentication code (CBC-MAC) component of CCMP provides data integrity and authentica- tion. CCMP is designed for IEEE 802.11i by D. Whiting, N. Ferguson, and R. Housley. & & 0 3 D G G U H V V H V D O O N Q RZ Q : (3 G H ¿ F L H Q F LH V but without the restrictions of the already-deployed hardware. The protocol using CCM has many properties in common with TKIP. Freedom from constraints associated with current hardware leads to a more elegant solution. As with TKIP, CCMP employs the 48-bit IV, ensuring the lifetime of the AES key is longer than any possible association. ,QWKLVZD\NH\PDQDJHPHQWFDQEHFRQ¿QHGWR the beginning of an association and ignored for its lifetime. CCMP uses the 48-bit IV as a sequence n u m b e r t o p r o v i d e r e p l a y d e t e c t i o n , j u s t l i k e T K I P. AES eliminates any need for per-packet keys, so CCMP has no per-packet key derivation function (Cam-Winget et al., 2003). Comparing WEP, TKIP, and CCMP WEP, TKIP, and CCMP can be compared as in the Table 1. As it is quite obvious from the previ- Table 1. Summary of WEP, TKIP, and CCMP comparison (Cam-Winget et al., 2003) WEP TKIP CCMP Cipher RC4 RC4 AES Key Size 40 or 104 bits 128 bits encryption, 64 bits authentication 128 bits Key Lifetime 24-bit IV, wrap 48-bit IV 48-bit IV Packet Key Integrity Concatenating IV to base key Mixing Function Not needed Packet Data CRC-32 Michael CCM Packet Header None Michael CCM Replay Detection None Use IV sequencing Use IV sequencing Key Management None EAP-based (802.1x) EAP-based (802.1x) 2163 Wireless LAN Setup and Security Loopholes ous discussion, CCMP is the future choice, and TKIP is only an interim solution. RADIUS SERVER AND AUTHENTICATION MECHANISMS To address the shortcomings of WEP with respect to authentication, a solution based on 802.1x VSHFL¿FDWLRQLVGHYHORSHGWKDWLQWXUQLVEDVHGRQ IETF’s extensible authentication protocol (EAP) as in RFC 2284. Its goal is to provide a foundation of architecture for access control, authentication, and key management for wireless LANs. ($3ZDVGHVLJQHGZLWKÀH[LELOLW\LQPLQG and it is being used as a basis for various network authentication protocols. :3$ ZL¿ SURWHFWHG access) is proposed to enhance the security of ZLUHOHVV QHWZRUNV WKURXJK VSHFL¿FDWLRQV RI security enhancements that increase the level of authentication, access control, replay prevention, message integrity, message privacy, and key distribution to existing WiFi systems. RFC 2284 states that, in general during EAP authentication, after the link establishment phase is complete (i.e., after establishing connection), the authenticator sends one or more requests to authenticate the peer (client). Typically, the authenticator will send an initial identity request, and that could be fol- lowed by one or more requests for authentication information. The client sends a response packet in reply to each request made by authenticator. The authentication phase is ended by the authenticator with a success or failure packet. Figure 2 shows a general EAP diagram. Figure 2. Authenticated wireless node can only gain access to other LAN resources (Strand, 2004) (See steps 1, 2, and 3 in the diagram) . the key resource, and the wireless devices are set to operate in a certain frequency band. 802.11 networks operate in the 2.4 GHz ISM band, which are generally license free bands. The more common. the S-band ISM. In the next sections, we will be explaining the wireless LAN basic setup and implementa- tion, WEP encryption schemes and others, EAP authentication through RADIUS server and. Develop- ing e -business: A strategic approach. Informa- tion Management & Computer Security, 10(4), 184-192. Standards Australia. (2004). Corporate gover- nance of information and communication