Cryptography

Everyone has secrets. Or at least some data you don’t want to show others, right? Vim is a common editor to be found on Linux systems. It has an option to create and use encrypted files. We will look at how to configure it and use this encryption capability.

Encryption is the process of fiddling with data so that others no longer can’t read it. The idea is that you still can, so when we speak about encryption, we can’t ignore decryption. This also means that we need a good cryptographic algorithm. This way we can store our original file into an encrypted version. Then when we later need the data again, we can decrypt it.

The world has changed a lot in the last era, especially when it comes to computing. This applies also to the services we run on our Linux systems. Some of these services (like rlogin), were previously the defacto tools to do administration. Now they are considered to be bad and insecure.

What makes a service insecure?

Services can become insecure when they have characteristics like:

• No (or weak) authentication
• No (or weak) encryption
• Insecure protocols
• Running as root

Authentication insecurities

One example might be if a program only requires a password or pin, without any information like an username. This happens often in physical solutions, but sometimes also in software. The risk involved is two-folded: it is easy to guess and provides no (or weak) accounting.