plone.formwidget.captcha 1.0a1

Buildout Installation

Add the following code to your buildout.cfg to install plone.formwidget.captcha:

[buildout]
...
eggs =
    ...
    plone.formwidget.captcha
    ...

...
[instance]
...
zcml =
    ...
    plone.formwidget.captcha
...

Captchas without server state

(From collective.captcha)

A view to generate a captcha image and/or wav file, and to verify user input against it.

A cookie is used to transfer state from one request to the next. The state is used, together with a server-side secret, to create a random string of characters, which in turn is displayed as a captcha image, or transformed to an audio file. Verification happens case-insensitively.

Note that the captcha ‘word’ is only usable for 5-10 minutes, after which the view will not accept it any more. Moreover, a different word will be generated for a given session key every 5 minutes.

This makes these captchas replayable for up to 10 minutes if a determined user keeps sending the same session id. Because of the server-secret though, captchas are not transferrable between sites.