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What is a captcha?
A captcha, short for "Completely Automated Public Turing Test To Tell Computers and Humans Apart," is a simple test designed to distinguish real users of a website from automated programs, such as bots. The main purpose of a captcha is to protect websites from malicious actors and ensure data security by preventing automated access to resources.
History of captcha
The idea of captcha was first implemented by AltaVista in 1997. The first version of captcha consisted of an image with distorted text that users had to recognize and enter into the appropriate field. This method proved to be quite effective and became a standard for protecting websites against spam and abuse. Today, this type of captcha is still widely used and remains relevant in the fight against bots.
Types of captcha
There are several different types of captcha, each with its own features and verification methods:
- Text captcha: Distorted letters and numbers that need to be recognized and entered.
- Graphic captcha: Images where users must select certain objects (for example, photos with vehicles).
- Audio captcha: Audio files with spoken numbers or words for people with disabilities.
- Problem-solving: Simple math problems that need to be solved to confirm that you are human.
Myths about captcha
There is a common myth that captcha can be easily bypassed by spam bots with human assistance. In reality, this is true, and many malicious actors use special services where people complete captchas for a small fee. This creates additional challenges for captcha developers, as they continuously seek new ways to complicate tests to minimize the possibility of bypassing them.