Japanese characters in a Yii Captcha widget?

Question

Working on a Japanese forum web app done in Yii. The problem is we are starting to get some english-language spamming since the captcha is in English characters and anyone who can read it can basically spam. I'd like to have the captcha in Japanese kanji, which is of multibyte string type. Anyone do a multibyte-captcha in Yii before? Any advice or links would help.

*It would also be cool if I could pre-define the characters that are displayed but that is bonus.

Answer 1

I have found the solution (at least for Japanese-language uses). Check out Yii veteran softark's awesome CCaptcha extension jcaptcha: http://www.yiiframework.com/extension/jcaptcha/