Back to Basics: My Opinionated 2025 sshd_config Hardening

In today’s fast-paced tech landscape, it’s common to find incredibly talented engineers mastering complex orchestrators like Kubernetes or crafting intricate Infrastructure as Code solutions. We’re living in an era of high-level abstractions, which is fantastic for productivity. However, this focus on the ’new and shiny’ can sometimes lead us to overlook the foundational bedrock upon which everything is built. It might seem a bit old-school to write a blog post about hardening SSH in 2025. Yet, these ‘basic’ skills are more critical than ever. In a world of ephemeral infrastructure and complex supply chains, securing the front door to our systems remains a non-negotiable first step. ...

December 3, 2025 · 8 min · 1625 words · Matteo Bisi

cryptsetup: How to Protect Entire Disks or USB Keys – Notes on technical_notebook

I have been using an encrypted USB drive for several years, which unlocks with biometric access. Recently, I started wondering how to achieve the same level of protection with other disks or USB keys. The answer is cryptsetup, a utility included in most Linux distributions. I’ve done some tests and documented how to use it in a repository I’ve named technical_notebook. I’ll use technical_notebook as a personal notebook—it will contain commands, concepts, and useful links. The purpose of the repo is to help me remember these details, keep them easily accessible, and perhaps assist others who have similar needs.

July 15, 2024 · 1 min · 99 words · Matteo Bisi