[hrjet]

Would appreciate thoughts on this alternative that we are developing:

https://github.com/librecaptcha/lc-core

The idea is to develop a framework for Captcha generators. A few sample generators are provided out of the box, but new ones can be written easily. The framework takes care of storing entries in the database, serving them as challenges through an HTTP API, and checking the responses.

From the README, why libreCaptcha:

  * Eliminate dependency on a third-party
  * Respecting user privacy
  * More variety of CAPTCHAs, tailored to your audience

The implementation has a long way to go (it was written by students trying to learn Scala), but would appreciate thoughts on the concept.

[ackbar03]

If you give me a captcha generator I can give you a captcha solver. You have no idea

[hrjet]

Agreed; a determined programmer could solve almost any Captcha given sufficient time and resources.

But we are not trying to create an unsolvable Captcha. For those websites that need something good enough to deter generic bots while not compromising privacy of their users, this might be a good enough alternative to reCaptcha.

Imagine a docker image which just works with out-of-the-box generators. Those who need more variety could create a custom generator with Javascript and drop it into a docker volume.