captcha

The term captcha was invented around 2000 by Luis von Ahn and Manuel Blum at CMU. Short for “Completely Automated Public Turing test to tell Computers and Humans Apart”, the word described a technology that had been in use since 1997 to deter bots on the internet.

Frustratingly, Wiktionary lists a first usage date of 2000 but doesn’t have a citation, while Wikipedia claims 2003. The 2003 date is clearly too late since their 2003 paper cites a 2002 paper that uses “CAPTCHA” in its title. This 2002 ACM newsletter by its inventors is the earliest publication I can find so far. Blum’s publication history doesn’t include anything that looks promising earlier. I suspect they were using the term in 2000, which is where the commonly cited date comes from, but didn’t publish anything using it until 2002.

Anyway, here’s a captcha from 1997: https://upload.wikimedia.org/wikipedia/commons/6/69/Captcha.jpg