Captcha

基本解釋

A CAPTCHA is a challenge-response test to determine that the response is not generated by a computer.
—一個(gè)騐証碼是質(zhì)問-響應(yīng)的測試以便於確定這個(gè)響應(yīng)是不是被一個(gè)計(jì)算機(jī)産生的。
He gives an example: a CAPTCHA in which each letter was always formed out of the same number of pixels.
他擧了一個(gè)例子：在一個(gè)騐証碼中，每個(gè)字母都是由一定數(shù)量的像素組成的。
Looking at things the other way around, a CAPTCHA system based on words that machines cannot read ought to be uncrackable.
從另一個(gè)角度看待事物，騐証碼系統(tǒng)基於機(jī)器無法辨認(rèn)的文字，應(yīng)該是牢不可破的。

For individual humans, CAPTCHA solving accuracy on popular sites was in the ballpark of just 85%.
FORBES: Those Scrambled Word Tests For Stopping Spambots Are Tough For Humans Too
As the social malware picked up steam, the captcha crackers were wildly busy earning their points.
FORBES: Social Media Brings a New Wave of Threats, Part 2
The captcha was a very effective defense and stopped the spread of Koobface in its tracks.
FORBES: Social Media Brings a New Wave of Threats, Part 2