Advise, I would like to make a secure form on the site without using captcha. What I've done:
- Introduced the session variable with the generated coded value, which is placed in the form field. When getting the form, the hidden field is compared with this value. If there is a discrepancy, naturally, a corresponding message is displayed and the form does not fall under processing.
- Introduced another session variable, which ensures that the form could not be sent more than 1 time per hour. That is, after submitting the form when the page is updated, its html markup does not appear on the page at all for an hour.
Question: what pitfalls does my script contain and what can we expect from cheerful hackers? In particular, the possibility or impossibility of sending this form from a third-party resource is of interest.