Re:Proof of work - an unobtrusive alternative to captchas
by jsn on Friday May 06, 2011 @06:42AM
(#2520586)
It will work, but the scheme has to be simplified some. Coins can be generated ahead of time, and then the client just pays a 0.001 bitcoin (via browser plugin, automatically) to the server instead of jumping through the captcha hoops. No trust is required, it's just a usual bitcoin payment.
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Re:Proof of work - an unobtrusive alternative to captchas
by limmeau on Friday May 06, 2011 @07:34AM
(#2520640)
I thought a bitcoin transaction was only considered successful after a sizable number of other bitcoin participants have based their successful computations on it?
If that is correct, bitcoin validation isn't fast enough for instantaneous forum postings when the spammers can be assumed to be as dishonest as fits them.
Re:Proof of work - an unobtrusive alternative to captchas
by jsn on Friday May 06, 2011 @07:40AM
(#2520647)
IIRC, you can almost instantly verify that certain bitcoin wasn't spent someplace else before, which would be good enough. Now, the attacker can use the same bitcoin for several web forms simultaneously, but 1) the scope of this attack is limited by the time window, and 2) if the server discovers a fraudulent transaction in, say, a few minutes, the spammy comment can be automatically deleted then.