The Comment Challenge plugin does a great job of preventing comment spam. It requires commenters to type a specific word in a Web form in order for the comment to be published. This plugin is being implemented on all of your blogs this month.
You may decide that you want to change the challenge word. This might be the case when you're getting an upswing in comment spam and suspect that someone may have "cracked" your word. Or, you may want to change your word periodically to prevent this from happening.
Changing your challenge word is easy to do.
1. Go to the Settings menu of your blog and select the Plugins tab.
Note that the Comment Challenge plugin is in your list of available plugins.
2. Select the Show Settings link for the Comment Challenge plugin.
This will open up the available settings for this plugin.
3. Change the challenge word in the two places where it appears in your settings.
In the example below, you would change the word 'challenge.'
4. Click on "Save Changes."
5. Rebuild your site.