|Ken Novak's Weblog
Purpose of this blog: to retain annotated bookmarks for my future reference, and to offer others my filter technology and other news. Note that this blog is categorized. Use the category links to find items that match your interests.
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Saturday, March 05, 2005
Hundreds of Miles Per Gallon
: Fareed Zacharia joins in and gets the vision: "the car of the future, a plug-in hybrid with a flexible-fuel tank". The engine has to be flexible with fuel, accepting ethanol, methanol, and gasoline, and the hybrid has to be "pluggable" so that it can use low-cost nighttime electricity. With much less fuel required, a high proportion can be non-petroleum derived (ie, ethanol, biodiesel, methanol, etc) so that hundreds of miles per gallon of petroleum products becomes possible -- all with today's technology. Naturally, FZ wants this mostly for national security reasons, but greenhouse gases would be reduced as well. 10:13:18 PM
Howto for UML
: Steps for installation and use of the mature User Mode Linux platform. For new development, see FAUmachine
: "We are working on an Open Source Virtual Machine which started out as a User Mode Linux, and which we therefore used to call UMLinux. Since the project has evolved from a User Mode Linux to a Virtual Machine we have chosen to give it the more appropriate name FAUmachine... FAUmachine development is supported by the European Community." 3:49:57 PM
: "the vserver project: It allows you to run linux inside linux: Any distributions inside any distributions. Each virtual server has its own packages, its own services, its own users and is confined to using some IP numbers only and some area(s) of the file system. You can think of them as virtual machines." All vms are linux, and they share the host kernel. So there is essentially no CPU overhead. VM disks can be resized, and vms moved easily, just like other vm solutions, getting many vm advantages with almost no overhead costs. Active development. 3:48:14 PM
Fingerprinting PCs wherever they connect to the Net:
". A doctoral student at the University of California has conclusively fingerprinted computer hardware remotely, allowing it to be tracked wherever it is on the Internet. In a paper on his research
, primary author and Ph.D. student Tadayoshi Kohno said: "There are now a number of powerful techniques for remote operating system fingerprinting, that is, remotely determining the operating systems of devices on the Internet. We push this idea further and introduce the notion of remote physical device fingerprinting ... without the fingerprinted device's known cooperation."
The potential applications for Kohno's technique are impressive. For example, "tracking, with some probability, a physical device as it connects to the Internet from different access points, counting the number of devices behind a NAT even when the devices use constant or random IP identifications, remotely probing a block of addresses to determine if the addresses correspond to virtual hosts (for example, as part of a virtual honeynet), and unanonymising anonymised network traces. .. One could also use our techniques to help track laptops as they move, perhaps as part of a Carnivore-like project [or to] obtain information about whether two devices on the Internet, possibly shifted in time or IP addresses, are actually the same physical device."
The technique works by "exploiting small, microscopic deviations in device hardware: clock skews." In practice, Kohno's paper says, his techniques "exploit the fact that most modern TCP stacks implement the TCP timestamps option from RFC 1323 whereby, for performance purposes, each party in a TCP flow includes information about its perception of time in each outgoing packet. A fingerprinter can use the information contained within the TCP headers to estimate a device's clock skew and thereby fingerprint a physical device. .. Our techniques report consistent measurements when the measurer is thousands of miles, multiple hops, and tens of milliseconds away from the fingerprinted device, and when the fingerprinted device is connected to the Internet from different locations and via different access technologies. Further, one can apply our passive and semi-passive techniques when the fingerprinted device is behind a NAT or firewall. .. For all our methods, we stress that the fingerprinter does not require any modification to or cooperation from the fingerprintee." Kohno and his team tested their techniques on many operating systems, including Windows XP and 2000, Mac OS X Panther, Red Hat and Debian Linux, FreeBSD, OpenBSD and even Windows for Pocket PCs 2002. ..
Although the paper says that "It has long been known that seemingly identical computers can have disparate clock skews," it goes on to conclude that "the main advantage of our techniques ... is that our technique can be mountable by adversaries thousands of miles and multiple hops away." " [via Mitch Kapor] 11:30:33 AM