Well I've not investigated but this software mentioned is probably for Linux, regardless. I would think that many whether on Linux or Windows hosting will not have the option to install any new sotware to make this work.
Certainly there must be some other method to achieve something similar. It's not being used as encryption/security rather just to thwart robots from completing the form.
What about hundreds of tiny images that can semi-randomly be put together to form something, or something similar that does not require more 3rd party software?
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