how to make secure sign up form

Question

i want my sign up form to be secure from hacker..i want all secret information can't easily open by wrong people..

i wan't some data become encrypted..

how to make it??

Answer 1

See:

PHP Security Guide

For form security, have a look at:

PHP Security Guide: Form Processing

I would suggest you for HTML Purifier actually:

HTML Purifier is a standards-compliant HTML filter library written in PHP. HTML Purifier will not only remove all malicious code (better known as XSS) with a thoroughly audited,
secure yet permissive whitelist