A CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) is a type of security measure used to determine whether a user is a human or a bot. It is designed to prevent automated systems from performing actions that should be limited to humans, such as creating accounts, posting comments, or purchasing tickets.
How does a CAPTCHA work?
The goal of a CAPTCHA is to present a challenge that is easy for humans to solve but difficult for bots. Common types include distorted text that users must type correctly, image recognition tasks, and simple puzzles. The goal is to exploit the differences between human and machine processing abilities.
What types of CAPTCHA are there?
- Text-based CAPTCHA: Users must read and type a distorted series of letters and numbers.
- Image-based CAPTCHA: Users select images that match a certain criterion, like "select all squares with traffic lights."
- Audio CAPTCHA: Users listen to a series of spoken letters or numbers and type them out, which is useful for visually impaired users.
- Checkbox CAPTCHA: Ask users to tick a box to prove they're human. Machine learning is used to differentiate between a human click and that of a bot.
Are there any drawbacks to using CAPTCHA?
CAPTCHAs are a major source of frustration for users, especially as they evolve to be more difficult to thwart advanced AI solvers. They can also pose accessibility challenges for people with disabilities. Studies show that the use of CAPTCHAs can result in drops in conversions for eCommerce stores.
What are CAPTCHA solver services?
CAPTCHA solver services are third-party services that use human workers or advanced algorithms to solve CAPTCHAs for bots. These services allow bots to bypass CAPTCHA challenges, significantly undermining their effectiveness. Solver services have become more prevalent, prompting the development of alternative security measures.