CAPTCHA
Technology & Computing abbreviation · Cybersecurity
| Stands for | Completely Automated Public Turing test to tell Computers and Humans Apart |
|---|---|
| Categories | Technology & Computing |
CAPTCHA stands for Completely Automated Public Turing test to tell Computers and Humans Apart, a cybersecurity abbreviation.
A challenge websites use to block bots, such as typing distorted letters, picking images that show traffic lights or ticking a box while the site analyzes behavior. It protects sign-up forms, logins and ticket sales from automated abuse.
Example: After three failed logins, the site shows a CAPTCHA before letting you try again.
Usage notes
Coined in 2003 by Luis von Ahn, Manuel Blum, Nicholas Hopper and John Langford at Carnegie Mellon University. Google's reCAPTCHA once used human answers to help digitize books and later to label photos. AI can now solve many visual puzzles, so newer systems such as Cloudflare Turnstile rely on invisible risk signals instead. Accessibility advocates criticize puzzle CAPTCHAs for excluding blind and low-vision users.
Related abbreviations
More cybersecurity abbreviations
- ATT&CK – Adversarial Tactics, Techniques, and Common Knowledge
- AV – Antivirus
- BEC – Business email compromise
- BYOD – Bring your own device
- C2 – Command and control
- CA – Certificate authority
- CASB – Cloud access security broker
- CEH – Certified Ethical Hacker
- CERT – Computer Emergency Response Team
- CIA – Confidentiality, integrity, availability
- CISO – Chief information security officer
- CISSP – Certified Information Systems Security Professional