Thursday, November 21, 2002

Real User:  Nice application of Cognitive and Biological Psychology... To authenticate a user, the system challenges them with a 3 by 3 grid of faces containing one passface and 8 decoy faces positioned randomly within the grid. The user responds by indicating the position of their passface in the grid. This challenge-response process is repeated with each of the user's remaining pass-faces - each time presented in a grid with 8 more decoy faces.       comments? [] 1:02:04 PM     Bluetoooth still sucks Bob Frankston explains why Bluetooth still sucks: it's all about the connectivity. We should learn from the example of X.400. X.400 was (is?) a mail protocol approved and required by essentially all the telecommunication agencies throughout the world. It was designed over a period of ten years yet failed against SMTP (Simple Mail Transport Protocol) which could be implemented in an afternoon. Like x.400, the Bluetooth was designed and promulgated before anyone could learn from the first generation. Bluetooth is designed to work in the specific cases imagined by its designers and thus will perform very well in precisely those scenarios and these are the scenarios touted in press releases. It's not surprising that if you don't use Bluetooth precisely as envisioned it will not work very well. There is a tendency to view these problems as anomalies and those of us who point them out are considered spoilers and are thus discounted. Link Discuss comments? [] 11:11:15 AM     72-mile WiFi link 72-mile WiFi link A researcher at the San Diego Supercomputer Center has built an FCC-legal, 72-mile long WiFi link, using high-gain, 2-ft. parabolic antenna, running at 1Mb/s. Holy crap! Link Discuss (via Raelity Bytes) posted by Cory Doctorow at 20:55 permanent link to this entry comments? [] 11:03:05 AM     WiFi: 4 channels, 3 dimensions WiFi gets another usable channel The CTO of a company called Cirond has released a whitepaper arguing that WiFi access points that overlap coverage can use four channels, instead of the traditional three. This opens up a new world of possibilties for packing 802.11b points more densely, on channels 1, 4, 8 and 11. The insight relies on the idea that by arraying access points on multiple storeys of a building, adding a third dimension to the overlap, you can minimize interference, even on channels that nominally overlap. Link Discuss (via /.) posted by Cory Doctorow at 09:14 permanent link to this entry comments? [] 10:57:27 AM

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