Unfortunate headline

Qurei says settlement expansion would complicate final solution

RAMMALAH, March 30 (Xinhuanet) -- Palestinian Prime Minister Ahmed Qurei has warned that Israel's settlement expansion in the West Bank would complicate efforts to reach a final solution, local press reported Wednesday.

Juggling DDR Freak

Perhaps the most amazing thing I have ever seen.

UPDATE: Until this.

UPDATE: Or maybe this.

WebHashcash — The End of Comment Spam

I am pleased today to announce WebHashcash (based on Hashcash by Adam Back), a fundamentally new mechanism for preventing spam on web sites of all kinds: blogs, discussion forums, wikis, and more. It guards against automated content posting, fake user registration, and ballot stuffing.

Astute visitors to my blog may have noticed for the past month a subtle little doodad on the comment submission form. That's WebHashcash functioning. While it's running, your CPU is maxed out, and when it's done (after a couple seconds), it will have generated an invisible "stamp" which it attached to your message, proving that your computer invested effort in generating the stamp. It is computationally infeasible to fake such a stamp — its presence proves an investment in CPU time.

The basic idea is that spammers only spam because it's so cheap to do so. The value of a spam posting to a spammer is far below the value of a legitimate posting to its author. Thus, it's possible to set a "postage" that's well below the value of legitimate postings, but above the value of spam. You therefore destroy the economics of spamming by requiring a negligible but real expenditure for each message.

This is qualitatively different from every other anti-spam mechanism in existence today. The basic concept behind virtually all other systems is to create some sort of "Turing test" which humans can pass but computers fail at. This typically involves optical character recognition, or responses to challenge questions. The problem with this approach is that it entails a constant arms race — as spambots become more intelligent, the anti-spam programs must be improved as well. There is no clear winner, and the trend seems to be favoring the spammers.

Enter WebHashcash. Unlike traditional anti-spam mechanisms, no attempt is made to actually prevent spammers from posting. But they have to pay the cost. And no spammer will, because it would bankrupt them to do so.

Since I introduced WebHashcash on my blog one month ago, it has blocked 670 out of 734 spam comments. The remaining 64 comments were exceptionally easy to delete as they all came from the same source. Furthermore, the spammers spent several minutes of CPU time in total in order to post the comments. If WebHashcash were in widespread use, spammers would quickly run out of CPU power attempting to post on WebHashcash-powered sites.

Please check out the WebHashcash web site for more information and for instructions on how to install it onto your web site.

I'm also interested in hearing your thoughts. Please post them here!