SD> Date: Sun, 8 Feb 2004 02:01:29 -0500 (EST) SD> From: Sean Donelan SD> Instead of Doubleclick tracking users with Cookies, they SD> would be able to track the unique computers from the MAC SD> address in the reverse DNS record over time. A MAC address is six octets. Append time past Epoch when IP was assigned; that's another four octets. Append six random octets. Encrypt. Make hostname-friendly using %x equivalent. One now has 32 characters that contain the MAC address and time the DHCP lease (or whatever) began, yet are meaningless to those who lack the key. Consider periodically changing the six random octets to protect users with long DHCP leases. It's extra hassle, but one can clearly have tracking _and_ protect user privacy. That leaves the issue of users changing MAC address to evade detection. However, the aforementioned DNS issues have no bearing on this problem, which is a separate topic. Eddy -- EverQuick Internet - http://www.everquick.net/ A division of Brotsman & Dreger, Inc. - http://www.brotsman.com/ Bandwidth, consulting, e-commerce, hosting, and network building Phone: +1 785 865 5885 Lawrence and [inter]national Phone: +1 316 794 8922 Wichita _________________________________________________________________ DO NOT send mail to the following addresses : blacklist@brics.com -or- alfra@intc.net -or- curbjmp@intc.net Sending mail to spambait addresses is a great way to get blocked.