These are the alternatives to Captcha (Completely Automated Public Turing test to tell Computers and Humans Apart):
- Honeypots – hidden form fields which hare filled out by robots, but not by humans on regular home pages.
- Time Period – evaluate time period between form download and form submission. Robots are usually fast and do not wait or wait just a short period of time in order to send as much submissions as possible.
- Simple Game
- Simple Logical Question
- Picture Alternative – “Click on …”
- JavaScript-generated Checkbox – new version in Google reCaptcha
- Sing-in using a Social Network Account (Facebook, Twiter or Google+) – good for blogs, can discourage users from submitting a comment
- Register/Login – enable only registered users to submit a form
- Paying Customers – enable only contacts (portal users, e-mail addresses) which have payed any amount of money for goods and services (on ebay, amazon, etc.)
References
Alternatives to Captcha