Hash Captcha

Why is this captcha better?

Hash Captcha is an invisible anti-spam solution that runs silently in the background. Your users never see it, never interact with it, and never get frustrated. Your forms stay protected while your visitors enjoy a seamless experience.

• No more distorted letters and numbers.
• No more traffic lights and motorcycles.
• No more stupid tasks.
• No more sending data to Google.

How it works

1. User loads a form (registration, checkout, contact, etc.).
2. Their browser silently calculates a cryptographic proof-of-work SHA-256 hash in the background.
3. By the time they finish filling out the form and click submit, the calculation is complete.
4. The hash is submitted with the form and verified on your server.
5. Spam bots waste excessive CPU resources trying to solve the puzzle and get blocked.

Key features

• No CAPTCHA images, checkboxes, or puzzles.
• No third-party APIs, Google tracking, or user data collection.
• Visitors never even know the protection exists.
• Adjust proof-of-work complexity from 2 to 5 leading zeros.
• Show protection only to guests and anonymous visitors.
• No external dependencies, works on localhost and intranet sites.
• Standard CS-Cart module — install via admin panel, works through native Antibot system.