Security – Dschoni.de

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 Wish.com (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.

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.

Introduction

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.

Security 101 – Security through Obscurity

Security 101 – Man in the middle attack

Introduction