How to securely delete a file and its contents

Need to delete the contents of a sensitive file? Instead of just deleting it with rm, look at this option first.


Learn how to purge data before deleting a file

Postfix Hardening Guide for Security and Privacy

Learn how to secure the configuration of Postfix with this guide, and increase both security and privacy.


Postfix is a common software component on servers for receiving or sending email. It has a lot of configuration options available, including those to improve your Postfix security. This Postfix security and privacy guide will help with hardening your Postfix configuration. After you are finished, your system will have improved defenses against spam, abuse, and leaking sensitive data. Why Postfix hardening? Every service that is connected to the internet is sooner or later to be abused by automated scripts.

The real purpose of login banners (on Linux)

We are used seeing login banners everywhere. What is the point of them, and why would they be useful? The answer is more surprising than you expected.


Login banners on Linux The first thing you might see when connecting to a Linux machine, is a login banner. Some systems use the default, others have put some serious work into it. Think of great forms of ASCII art, or a lot of impressive text. You might be surprised to learn the real reasons for having a banner in the first place. In this article we will discuss the purpose, and determine how we can improve the quality of our login banners.

Privacy Policy

Learn more about our promises when it comes to privacy in this privacy policy.


Privacy is important, so we limit the amount of information we collect. We stripped most of the external services that we used in the past. What we still use and why: Log file to store and process requests (e.g. abuse of our resources) Webmaster tools (to monitor the health of the website, does not store visitor information) Not in use Technology Rationale Analytics (e.g. Google Analytics) We don’t want to store sensitive information if not needed, especially not at an external party Cookies This website does not use cookies to maintain sessions Got any questions regarding privacy and or how we store or use information?