Corporate wireless LAN security is Extensible Authentication Protocol-Subscriber Identity Module(EAP-SIM). This method enables the user to gain access to the wireless network by using a SIM card to be authenticated through EAP. The card contains the key and/or passwords, granting access to the user once the card has been entered. Overall each variation of eap has its benefits however, the only newly approved standard is PEAP. It is likely that in the near future, each company will have to either convert to PEAP or enable their variation of EAPto work with other variations WPa was intended for short intermediate use. However. the 802.1 li release was delayed so a newer intermediate security method, called WPA2, is being released. The next edition of WPA is identical to the old version in every way, except that it uses AES encryption to ensure protection for firms where encryption is a must. Overall WPA/WPA2 is a temporary yet very secure solution for individuals and companies who cannot wait for the release of 802. 1li and need immediate security. 4.4 Virtual Private Networks(VPN A Virtual Private Network is a private network that uses a public network to connect emote users or sites together"(Tyson, 2001). VPNS, having extra security features, were created to make a way for users to connect to a network. There are four parts that make a VPN secure: " Firewalls, Encryption, IPSec, and AAA Server"(Tyson, 2001) A VPN firewall is the same as any other firewall- it is setup to block and allow only certain ports, and it is also designed to allow only packets which it does not think are malicious. This may sound trivial, but a firewall is a necessary entity in the VPN so that viruses and Trojan horses cannot compromise the VPN server. There is no specific encryption technique that is required in a VPN; however, three main techniques are used. The first technique is Symmetric Key Encryption, where each computer on the network has the key, enabling them to decrypt the packet when arrives.An identical symmetric key is used on each computer, which means that the key needs to be changed frequently so hackers will not be able to analyse packets and break into the network. The next method is Public Key Encryption, which uses a public key and a private key. The sender encrypts the packet with their private key(which they only know), and the receiver decrypts the packet with the senders public key. This system is similar to the Symmetric key, except that two different keys are used instead of only one. In order for this method to work, each user must have some way to securely get the public key from each sender. The last way to encrypt is with Pretty Good Privacy(PGP), which uses session keys to ensure protection. A new session key is created for one session per user, and with each new session or new user, a different session key is produced. The PGP system then becomes a public key system as it encrypts the packet and the session key to the users public key. These new encrypted packets and keys are sent to the receiver, who in turn uses his/her private key in decryption. These are the three widely used techniques; but because there is no encryption standard in VPN, any other type of encryption can be used or adopted to fit a VPN system Internet Protocol Security Protocol (IPSec) is another secure method used in VPNs to ensure privacy protection. IPSec is a simple system using two techniques to encrypt messages across the network. The first method is funnel, which means that the entire packet is encrypted with a key, including the header. The second method is transport, which only encrypts the data section of the packet and not the header Both ofCorporate wireless LAN security 275 is Extensible Authentication Protocol-Subscriber Identity Module (EAP-SIM). This method enables the user to gain access to the wireless network by using a SIM card to be authenticated through EAP. The card contains the key and/or passwords, granting access to the user once the card has been entered. Overall, each variation of EAP has its benefits; however, the only newly approved standard is PEAP. It is likely that in the near future, each company will have to either convert to PEAP or enable their variation of EAP to work with other variations. WPA was intended for short intermediate use. However, the 802.11i release was delayed so a newer intermediate security method, called WPA2, is being released. The next edition of WPA is identical to the old version in every way, except that it uses AES encryption to ensure protection for firms where encryption is a must. Overall, WPA/WPA2 is a temporary yet very secure solution for individuals and companies who cannot wait for the release of 802.11i and need immediate security. 4.4 Virtual Private Networks (VPN) “A Virtual Private Network is a private network that uses a public network to connect remote users or sites together” (Tyson, 2001). VPNs, having extra security features, were created to make a way for users to connect to a network. There are four parts that make a VPN secure: “Firewalls, Encryption, IPSec, and AAA Server” (Tyson, 2001). A VPN firewall is the same as any other firewall – it is setup to block and allow only certain ports, and it is also designed to allow only packets which it does not think are malicious. This may sound trivial, but a firewall is a necessary entity in the VPN so that viruses and Trojan horses cannot compromise the VPN server. There is no specific encryption technique that is required in a VPN; however, three main techniques are used. The first technique is Symmetric Key Encryption, where each computer on the network has the key, enabling them to decrypt the packet when it arrives. An identical symmetric key is used on each computer, which means that the key needs to be changed frequently so hackers will not be able to analyse packets and break into the network. The next method is Public Key Encryption, which uses a public key and a private key. The sender encrypts the packet with their private key (which they only know), and the receiver decrypts the packet with the sender's public key. This system is similar to the Symmetric key, except that two different keys are used instead of only one. In order for this method to work, each user must have some way to securely get the public key from each sender. The last way to encrypt is with Pretty Good Privacy (PGP), which uses session keys to ensure protection. A new session key is created for one session per user, and with each new session or new user, a different session key is produced. The PGP system then becomes a public key system as it encrypts the packet and the session key to the user’s public key. These new encrypted packets and keys are sent to the receiver, who in turn uses his/her private key in decryption. These are the three widely used techniques; but because there is no encryption standard in VPN, any other type of encryption can be used or adopted to fit a VPN system. Internet Protocol Security Protocol (IPSec) is another secure method used in VPNs to ensure privacy protection. IPSec is a simple system using two techniques to encrypt messages across the network. The first method is tunnel, which means that the entire packet is encrypted with a key, including the header. The second method is transport, which only encrypts the data section of the packet and not the header. Both of