The OpSec Series - Authentication

This post is part of a larger series. You can find all posts over here. We have arrived at one of the most hated parts of security: Authentication. Everyone knows the frustration of having to type in a username and password before accessing the systems you need to do your work. You even need specialized applications in order to keep track of all of these credentials. I sometimes feel like a stamp collector but instead of collecting stamps, I am collecting passwords....

March 14, 2023 · 19 min · 4025 words · Valentijn Harmers

The OpSec blog series - Chat platforms

This post is part of a larger series. You can find all posts over here. Hello and welcome to a new blog post in the OpSec blog series. As already mentioned in the previous post, this one will be about chat platforms. I can still remember a time when I was in school and carried around a Sony Ericsson J110 dumb phone. I didn’t use it much. It was just for contacting my parents in case of emergencies....

October 1, 2022 · 37 min · 7768 words · Valentijn Harmers

The OpSec blog series - E-mail encryption

This post is part of a larger series. You can find all posts over here. Welcome to the second blog post in this blogging series. I recommend reading the introduction post before starting with this one. Email is one of the oldest ways to communicate on the world wide web. And since the internet was created with openness in mind, so it shouldn’t come as a surprise that e-mail wasn’t designed to be very secure....

September 13, 2022 · 30 min · 6278 words · Valentijn Harmers

Creating a digital life raft

Over the span of our lives, we accumulate a lot of stuff. Some of this stuff is precious to us so we keep it in a secure place like a safe or strongbox. Some of this precious stuff can also be digital and therefore must be secured into digital strongboxes and safes but what happens when you lose the key? When your work in IT, you have a minimum of two employers: the company you work for and your family....

September 9, 2022 · 4 min · 750 words · Valentijn Harmers

The OpSec blog series - Introduction

Have you ever had the desire to improve the security of your systems but had no idea how to do it? You might have read all kinds of articles on the web about hacked companies that needed to pay large sums of money to get access to their data again. But what can you do, when you are just a system administrator of a small company with a non-existent security budget?...

September 7, 2022 · 11 min · 2221 words · Valentijn Harmers

Passwordless LUKS setup with Clevis

Typing your password at every system bootup might get you annoyed at times. Especially when you are used to Windows and macOS systems which store the disk decryption password in the TPM. But what if I told you that you can also achieve this on your Linux setup. We can use an application called ‘Clevis’ to get the job done. I will describe the installation and configuration steps for Ubuntu and Fedora, but the steps should be about the same for other Linux distro’s....

August 2, 2022 · 2 min · 267 words · Valentijn Harmers