Thesis on wlan security


thesis on wlan security

Multigroup Access, multigroup access is achieved with the use of multiple ssids mapped to wired network vlans, as previously described in this chapter). If an fhss scheme is selected for RF engineering reasons , it is recommended that the designer investigate using a VPN overlay solution as outlined in the "VPN Overlays" section earlier in this chapter. Only three channels that have no overlap. Enterprises should change the default Service Set Identifiers, which are essentially the names of each access point. Each wireless-equipped laptop should be secured by deploying a personal agent that can alert the enterprise and user of all security vulnerabilities and enforce conformance to enterprise policies. The 802.1X standard addresses the need for more robust authentication, and the 802.11i standard's Temporal Key Integrity Protocol ( tkip ) provides for more robust encryption. At the same time, their narrow focus means the signals are less likely to spill out into the street, where a war driver can capture and exploit. Because a simple wlan can be easily installed by attaching a 50 access point to a wired network and a 40 wlan card to a laptop, employees are deploying unauthorized wlans even when IT departments are slow. Because many security features, such as the use of WEP or VPNs and open broadcast of ssids, are controlled on the access points and stations, policies should be in place to forbid the reconfiguration of access points and wlan cards to alter these features. Allow access to: 00:01:42:0E:12:1F 00:01:42:F1:72:AE 00:01:42:4F:E2:01 But MAC addresses are sniffable and spoofable.

Wlan security : Best practices for wireless network security

Given enough data, a persistent attacker can use freeware tools to crack WEP. For example, you may prohibit peer-to-peer networking while permitting logged guest sessions through specific APs with limited destinations, protocols, duration and bandwidth. The StillSecure Border Guard from Latis Networks provides both intrusion detection and content filtering at the wlan gateway. Although MAC authentication and filtering can be bypassed with spoofing by an attacker, it still should be considered for the same reasons that WEP should be utilized when there is no other alternative. Network designers must make a business risk decision on what applications are acceptable to run in this environment. This is a business risk decision that the network designer must make. Enterprises may need to audit user activity; hot spot providers must record sessions to feed billing systems and generate revenue. Using WEP is like locking your office desk. Like 802.1X, portals let stations authenticate securely with legacy credentials and existing user databases. MAC authentication and filtering mitigate an attack from a low-level attacker. Few companies offer thesis on wlan security Ethernet access to visiting customers or business partners. Always slower than equivalent Layer 2 split.


However, attacks on the wlan itself require a different solution. Or should you try to ban wireless, despite its business advantages and the unnerving suspicion that rogue access points (APs) will crop up anyway? Integrate wireless networks and devices with existing management infrastructure. Reconnaissance: Discover Target Network, although thesis on wlan security the attacker can discover the wlan network topology, he should be able to determine only a limited subset of the topology behind the firewall device by looking at the characteristics of the traffic for the applications permitted through the firewall. These provide focused connectivity for your users. Commodity pricing, retail distribution and setup wizards have made it trivial for employees to install rogue APs, which can expose corporate assets to outsiders and interfere with wlan performance. In many instances, these radios do not have an inherent equivalent security scheme comparable to WPA and 802.11i.


One-way authentication VPNs are also vulnerable to man-in-the-middle attacks and a number of other known attacks. The firewall is configured to allow the pre-WEP/WEP-only clients to connect to the application servers needed for the wlan clients to perform their designated functions. Tools can also create baseline reports against which to compare future results, so that changes can be investigated and new problems remedied. Serious security breaches-like wired network intrusion, theft of confidential data thesis on wlan security and forgery-were far less common, according to the survey. Nonetheless, if you don't have a remote access VPN, consider mobile VPNs as a wireless security alternative.


thesis on wlan security

Wireless, local, area, network, security wLAN, security )

Insecure wireless user stations such as laptops pose an even greater risk to thesis on wlan security the security of the enterprise network than rogue access points. Freeware, such as NetStumbler and Kismet, and other commercial scanners can survey the airwaves for rogue access points and some network vulnerabilities. Steps to securing wireless networks, if you don't know what you're defending and why, your security measures are just shots in the dark. Compute ICV for message Compare with received ICV wlan Security 35 Shared Key Authentication When station requests association with Access Point AP sends random number to station Station encrypts random number Uses RC4, 40 bit shared secret. These protect more than the login-they proxy data over a SSL/TLS tunnel. Larger enterprises with more complex wlans that allow hundreds of stations to roam between access points may require more complex filtering from remote authentication dial-in service (radius) servers. This is an introductory tutorial that covers the basics of Wireless Security and how to deal with its various modules and sub-modules.


802.1X is more transparent, but requires configured supplicant software. This is the final layer of defense against exploitation that could derive its source from the pre-WEP/WEP wlan. Another option is to concentrate access at a new thesis on wlan security type device: a gateway tailored for wireless LANs. Plaintext XORed with long key stream of pseudo random bits. Vlan 10 is connected to additional security devices that inspect the traffic for proper behavior and authorization. A tunnel controls access to the visitor's own network; 802.1X controls access to the guest wlan. Associates with strongest AP regardless of ssid. Network Access: Gain Write Access, this attack is partially mitigated for the data on the interior of the firewall by the filtering done by the infrastructure.


Some clients allow * as ssid. Sniff packets Identify IP addresses Detect signal strength But may sniff your neighbours Wireless Intrusion Detection AirMagnet, AirDefense, Trapeze, Aruba, wlan Security 54 Access point audits Review security of access points. For instance, legacy pre-WEP or WEP 802.11b clients would use a dedicated 802.11b wlan infrastructure, whereas the rest of the corporation would use WPA/802.11i security on a separate 802.11b or 802.11a infrastructure to gain access to the corporation. Some switch between alternate ascending and descending counters. Wlan Security 28 War Driving prosecutions February 2004, Texas, Stefan Puffer acquitted of wrongful access after showing an unprotected county wlan to officials June 2004, North Carolina, Lowes DIY store Botbyl convicted for stealing credit card numbers via unprotected wlan. Wlans are no different. Security policies should define rules for "walled garden" guest access. Aluminium cake tin Chinese cooking sieve wlan Security 23 WarDriving Software Laptop 802.11b,g or a PC card Optional: Netstumbler And many more Laptop 802.11b,g or a PC card Optional: Global Positioning System Car, bicycle, boat Logging of MAC address, network name. The AP should be managed from a dedicated vlan thesis on wlan security on the wired side of the network or through the vlan that corresponds to the wlan that uses a more advanced security framework. When retransmission may waste significant time.


Wireless security - Wikipedia

Keeping your wlan safe Like any other network segment, wlans require configuration and monitoring. But consider roaming issues. The academy recently installed a wlan security suite and plans to offer campus-wide wireless connectivity by fall. It is especially going to help specialists like network engineers, database managers, analysts, programmers and other such professionals who are mainly responsible for applying appropriate countermeasures to secure devices and applications. Brute force takes 1019 years for 104-bit key. Wi-Fi Protected Access (WPA) is a security enhancement for current-generation wlan hardware. Now is the time to start playing catch-up with wlan security. Nids can be leveraged to catch wired network intrusions originating from the wlan. Security parameters and access rules are configured on a central policy management system and pushed to devices, supported by mobile device agents and client software. As West Point and thousands of other organizations are now discovering, wlans can be made secure if you're smart about how you integrate wireless with your wired enterprise, leverage your existing security tools and select the right security technologies-from. Alternatively, a designer can look to the vendor to provide a vendor-specific solution. When shared-key authentication is enabled, stations can associate with the AP only if they have a 40- or 128-bit key known to both parties. The network designer must consider this before adding more application support that requires these new types of features while still trying to maintain the use of the legacy device.


Wlan, security - A Layered Approach Computerworld

LLC has same 48-bit addressing as Ethernet. Multiple APs with same ssid form Extended Service Set. To eliminate the threat of intruders connecting to your wlan from the parking lot or the floor above you where connection speeds will be greatly reduced, access points should be configured to not allow the slower connection speeds. Recent improvements in wireless protocols and infrastructure technologies make "wlan security" a realistic goal, not a laughable oxymoron. Client tunes to AP channel. While the attention on the pitfalls of wlans has inspired some enterprises to ban wlans altogether, many security-conscious enterprises are confidently deploying secure wlans by implementing the following practical steps to protect their information assets, identify vulnerabilities and protect the network from wireless-specific attacks. Wlan Security 14, access Point Roaming Channel 1 Channel 4 Channel 9 Channel. With the cost of a wireless infrastructure decreasing with each innovative development, it is becoming easier for people to use for work and play anywhere they desire. Are passwords and community strings secure?


Wlan, security : wlan, security, request PDF

Mutual authentication wireless VPNs offer strong authentication and overcome weaknesses in WEP. Weca (Wireless Ethernet Compatibility Alliance) promoted Interoperability. However, it is something to consider because it eliminates a low-level attacker even though it is not a deterrent against a mid-level to high-level attacker. Renegade Access Points Unauthorised wireless LANs. Network Services Placement, in the legacy environment, the wlan clients still might need to access dhcp or DNS resources on the wired enterprise network, so the additional security devices need to either provide these services or allow the. Reasons may be interference or range. Sender waits for clear air, waits random time, then sends data. Depending on the size of your enterprise and the level of risk wlan opens thesis on wlan security up, you may want to start with the security 802.11 offers out of the box.


Login can be accomplished with any browser, without preconfigured credentials or keys. Key stream is function of 40-bit secret key 24 bit initialisation vector Ciphertext is transmitted. The same insecurity can come from network vulnerabilities originating from improperly configured wlans. Nevertheless, these can be your first line of defense. Wireless traffic is easily recorded. If portion of prng input is exposed, Analysis of initial key stream allows key to be determined. VPNs can employ strong authentication and encryption mechanisms between the access points and the network, and radius systems can be used to manage authentication, accounting and access to network resources. Wlan Security 38 Passive WEP attack If 24 bit IV is an ascending counter, If Access Point transmits at 11 Mbps, All IVs are exhausted in roughly 5 hours. Reusing deployed clients is one thing, adding new clients and policies quite another.


Wlan, security, policy : eTutorials

Default community strings, default passwords. It's critical to identify business assets that must be protected and the impact of damage, theft or loss. In short, early adopters have been lucky. Configuration scanning Check that stations are securely configured. A man-in-the-middle attack can intercept and use these values to access your wlan. This filtering can include any of the following techniques: A network designer might want to consider using MAC authentication and MAC filtering with the pre-WEP/WEP devices. Commercial directional antenna 25 mile range from hilltops. RC4 can use key sizes from 1 bit to 2048 bits. AP Beacons without ssid Essid_jack sends deauthenticate frames to client ssid then displayed when client sends reauthenticate frames wlan Security 20 Basic Service Set (BSS) Interception Range thesis on wlan security Station outside building perimeter.


These newer devices utilize the WPA/802.11 security framework to gain the security benefits outlined in the "Embedded Security Solutions" section earlier in this chapter. Accordingly, your choice of AP will impact your wlan topology (see "Alternative wlan Network Topologies below Firewalls can provide both access control and VPN termination. Wlan meets LAN, consider how new wlan segments will be integrated with and reuse components thesis on wlan security of your wired infrastructure. Wlan policies should begin with the basics of forbidding unauthorized access points and ad hoc networks that can circumvent network security. A tunnel prevents eavesdropping from end to end; WEP/tkip prevents eavesdropping on the air link only. Wlan Security Download ppt "Network Security Lecture 8 Wireless LAN Security wlan Security.". Network Access: Gain Read Access. Plaintext encrypted via RC4 Provides confidentiality. However, most of these incidents were problems waiting to happen: rogue APs, stations associating with the wrong AP and war driving. New rogue access points and other vulnerabilities can arise after a scan and will not be detected until the next time a network administrator surveys the network. The trunk from the AP is connected to an Ethernet switch. 1,099,511,627,776 keys 170 days on a modern laptop Find which key decrypts ciphertext to plaintext.


Network, security : wlan, security, tuomas Aura

When policy requires secure wlan access to just one or two applications, secure application protocols (secure e-mail, secure file transfer, SSL-protected Web GUIs) may be sufficient. Donald Welch, associate dean for information and education technology at the.S. But portals don't encrypt data; they only provide secure authentication. Similar to the effective discovery of network vulnerabilities, policy enforcement requires 24/7 monitoring of a wlan. However, in determining the password, the attacker might provide information that a network administrator can use to detect the intrusion attempt. Consider how wireless changes the rules for office visitors. Industrial, Scientific and Medical band. It will work with either 40bit or 128bit WEP.


This attack is partially mitigated for data on the interior of the firewall by the filtering being done by the firewall. Additionally, there are devices that can support WEP with tkip that will defeat a low- and mid-level attacker, but they do not provide assurance against a patient high-level attacker. So, don't ban the wlan Despite all the dire warnings about wireless security, there are a lot of unprotected wlans out in the world, ripe for picking. The capability to obtain these types of radios and put them into a promiscuous mode is harder than with standards-based 802.11 scenarios. WPA migration mode was designed specifically to migrate WEP clients to WPA without having to change the networking infrastructure significantly. Disabled means the wlan operates in "open system" mode-any station can join because they know the network's Service Set Identifier (ssid) or by capturing beacon frames broadcast by APs. Group policy changes and firmware updates can be pushed from a central point, and APs can be audited for compliance. If found, reassociates with new. Cant listen for collision while transmitting. Extended Service Set (ESS) Multiple cells wlan Security 7, independent Basic Service Set (ibss ad-hoc mode For meetings, conferences or other places where wireless infrastructure (access points) thesis on wlan security doesnt exist. The most advanced wireless IDS involves the real-time monitoring of 802.11a/b/g protocols. In larger wlans, wireless gateways can provide tunnel persistence when stations roam. In this fashion, you can have a vlan with no WEP and apply additional security checks, such as network IDS and firewalling, to secure the applications on that vlan.



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