End of comment spam?
Posted by Richard on May 14, 2005
I understand that some blogs — the ones with lots of readers — have a problem with spam in their comments. To such a degree that some have given up and disabled comments.
At this point, I have trouble relating. I’m not exactly overwhelmed with comments (thanks, VB, for your contributions). Or readers, for that matter, although I’m thrilled to see that I’ve climbed from Slimy Mollusc to Flippery Fish in the TTLB Ecosystem (watch out, you Crawly Amphibians, I’m coming through!).
But, if by any chance, you’re a reader who has a blog with a spam problem, you might want to look into the solution offered by David Schneider-Joseph, WebHashcash. Here’s his explanation:
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.
WebHashcash strikes me as remarkably clever and elegant. The installation instructions look coherent and complete; it’s not trivial, but it’s not rocket science. It does depend on Java/Javascript, but Schneider-Joseph addresses that in the comments:
On my blog, if a WebHashcash stamp is not submitted for whatever reason (usually because the user’s browser does not have Java support), the comment goes into a moderation queue, and is displayed once approved by a moderator. In this way, a minimum amount of inconvenience is created for users without Java, but the vast majority of users who have it can post instantly.
If you implement it that way, I don’t see how even the Lynx Luddites can object. Or, just screw them and accept comments only from people who recognize that this is a new century. 😉
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