Cracking CAPTCHA is difficult and the algorithm driving it is patented. However, it was made public because CAPTCHAs are just not a novel algorithm but a difficult case of artificial intelligence. Hence, reverse engineering it is challenging.
Deciphering CAPTCHAs require three primary capabilities. When the following capabilities are used in sync, it is then that deciphering a CAPTCHA becomes difficult. The three capabilities are as follows:
- Capacity of consistent image recognition: No matter what shape or size an alphabet appears, the human brain can automatically identify the characters.
- Capacity of image segmentation: This is the capability to segregate one character from the other.
- Capacity to parse images: Context is important for identifying a CAPTCHA, because often it is required to parse the entire word and derive context from the word.