Crypto-Scam and the exponential function

Since several years, I’m interested in crypto-currencies. I’m active in some chat groups on the topic on several platforms, one of them being Telegram. Every once in a while, I get messaged by people with very professional profile-pics, a trustworthy name („Stan“) and a very creative opener („Halo!“[sic!]). The person I am, I usually reply to spam and go with the conversation. Recently, one of those conversations brought up a homepage, where you can supposedly make A LOT of money by automatically investing in crypto currencied and other. But how much is a lot and can that actually be true?


Using spot-color in LaTeX for print-post-processing

I like to use LaTeX to produce nice looking PDF files for printing. So far that has worked pretty well, but in a recent project I ran into issues, so I want to document the solution here. In some printing jobs, there is post-processing involved e.g. when cutting stickers, when putting gold-foil over certain parts of the design or when embossing. In that case, the files need to follow a certain scheme that this areas can be correctly recognized.

In my use-case, the cut-contour lines of a sheet of stickers needed to be given as a separate colour with a certain name. All solutions that I found, where tailored towards proprietary PDF creators like the Adobe Suite or something in this direction. Even harder, if you search for the german words „Volltonfarbe“ in combination with „Latex“ (or even „LaTeX“), you will end up with results offering to buy latex based paint which is not very helpful. „Volltonfarbe“ in this context translates to „spot-color“ and it is very well possible to use spot colors in a LaTeX document.


Security 101 – Security through Obscurity

This article is the second post on security terms explained in easy, every-day-life examples. The first post can be found here.

We meet our friends Alice and Bob again, who send each other letters and Eve, who doesn’t like what they have. Eve therefore tries to have a look in their letters, trying to find out secrets about Alice and or Bob to gain advantage she can use against them.

Let’s imagine following scenario: Bob has bought a new lock to his mailbox. This lock is advertised as the ultimate smart lock, with machine learning, blockchain and AI and has a simple button that recognises the user. Unfortunately Bob ordered the lock on (reference for readers from the future: back in 2021, this was an internet shopping platform for cheap stuff, with often surprisingly bad outcome). The lock arrives and exactly as the description states, consists of only one single black button instead of a keyhole. Bob installs the lock and is very happy. Each day, he simply presses the button and the mailbox opens.


Figment – Not just a kid’s game

I had some free time yesterday and saw a new game on the free Stadia Pro section, so I gave it a try. And boy was I surprised. The game is called Figment and takes place in the mind of a person, where you stroll trough different areas of the brain. The protagonist is a clumsy little something who would rather enjoy a cold drink than being controlled by you. Together with an overly optimistic bird, the duo has to chase down a sinister enemy, solving riddles on the way.


Security 101 – Man in the middle attack

This post is the first in a short series of articles about essential concepts in IT security to explain common security flaws in simple, everyday-life terms. This idea developed during an online presentation about IT security in the medical sector.


A man in the middle (MITM) scenario happens, when an unexpected party becomes part of an exchange between to individuals or entities. Let us imagine two friends somewhere in the world are good friends and are writing each other letters from time to time. To make things easier, we will name the two people Alice and Bob, which is a very common choice in information security. When Alice sends a letter to Bob, Bob can read this letter and respond to it by writing his own letter back to Alice. At some point, a malicious third party becomes interested in the communication between Alice and Bob. Let’s stick to common naming and call that malicious party „Eve“ (from eavesdropping). Eve is interested in the communication between Alice and Bob because she hopes to find information that she can use either to gain a personal advantage or to inflict harm on Alice or Bob. Eve decides to wait in front of the house of Bob every morning until the postman arrives and steal the letters from Bob’s mailbox. To stay undetected, she opens the letters (probably using hot steam), reads them, reseals the envelope and puts the letter back into Bob’s mailbox. This scenario works well for letters Bob receives from Alice, but is quite hard for letters Bob sends to Alice. In order to have all information on the exchange, Eve would also need access to the mail Bob sends out to Alice.