Skip to content

Get Started

ALTCHA is a protocol designed for safeguarding against spam and abuse by utilizing a proof-of-work mechanism. This protocol comprises both a client-facing widget and a server-side verification process.

We provide an open-source JavaScript widget that seamlessly integrates with any website. The server-side implementation, tailored to your stack, typically involves only a few lines of code.

ALTCHA stands for “ALTernative to tell Computers and Humans Apart,” offering an alternative approach to reCAPTCHA and other CAPTCHA systems.

Goals and Benefits

ALTCHA was developed with specific goals in mind, primarily addressing privacy concerns and eliminating reliance on cookies. These goals also translate into distinct advantages when compared to traditional puzzle-solving methods:

  • Frictionless experience: Puzzle-solving often poses a cumbersome challenge, leading to user dissatisfaction due to its tedious nature.
  • Effective spam protection: Utilizing the proof-of-work mechanism as the primary defense strategy, followed by the Spam Filter as the secondary line of defense, capable of deterring even the most sophisticated spam.
  • Cookie-free solution: ALTCHA doesn’t use cookies which means there’s no need for a cookie banner.
  • Lightweight implementation: Leveraging modern cryptography supported by all modern browsers, ALTCHA simplifies integration with minimal code.
  • Self-hosting capability: ALTCHA verification can seamlessly integrate into any server environment, irrespective of the programming language used, eliminating reliance on third-party infrastructure.
  • Machine-to-Machine adaptability: As the importance of AI and the API economy grows, there’s an increasing necessity to enable machines to “pay” for their requests. Explore the proposal on M2M ALTCHA.

Quick Start