Captcha & Captcha Break

Sebenarnya sudah lama penasaran, mengapa captcha (Completely Automated Public Turing test to Tell Computers and Humans Apart, situs utama) di PHPBB yang default mudah dijebol sehingga banyak spammer2 register sebagai member di forum phpbb.

Ternyata konon gambar di captcha bisa dicrack / dikenali oleh program. Beberapa artikel (baca sendiri) :

1. http://hoozi.wordpress.com/2007/10/24/how-to-breakcrack-online-captcha/
2. http://hoozi.wordpress.com/2007/10/24/how-to-break-googlegmail-or-orkut-captcha/
3. http://www.cs.sfu.ca/~mori/research/gimpy/
4. http://www.webuser.co.uk/news/128063.html
5. http://forums.hypography.com/computer-science/8989-cracking-captcha.html