Appendix A: Glossary

X

Xauth eXtended authentication. An IKE extension that permits the use of legacy protocols such as RADIUS, SecurID, and OTP. For more information, see the Internet Draft at http://www.vpnc.org/ietf-xauth/draft-beaulieu-ike-xauth- 02.txt.

Xsupplicant An 802.1X supplicant developed by the Open1X project that runs on Linux platforms that permits authentication to a RADUIS server and use of the EAP protocols. For more information, see http://open1x.sourceforge.net.

Z

zero-day attack An attack of any sort that exploits a vulnerability that has not yet been officially discovered and patched. Because systems are not protected from zero-day attacks, these attacks can aggressively propagate throughout the world in a matter of hours. Zero-day attacks consume incredible amounts of network resources when propagating and can use unique code that most antivirus software does not detect.

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