Using HTTP digest authentication in web applications as an alternative to SSL for protecting usernames and passwords.

How to compile and install the suhosin security module for PHP on Ubuntu Linux Server

Creating secure web applications is extremely difficult. Learn the basic techniques of writing tamper-proof web apps in Perl and other languages.

HTML form data and cookies can easily be altered by malicious users, especially the so-called "hidden" fields. Learn how to detect tampering using HMAC signatures.