Introduction In the first article, we saw the two kinds of cryptosystems, symmetric and asymmetric, and how to generate entropy and we upload to our development board. In this article, we are going to see how to generate our RSA keys and the program display these keys on the LCD. Walking through the world of coprime The RSA encryption algorithm is based on the prime number and the coprime, so, it’s important to understand these concepts, and we are going to walk through to see what are they.
I decided to create a project for generating RSA keys directly from an embedded board. This board will generate data and display these keys to a LCD. I wanted to made this ludicrous project, because, the cryptography is a part of IT security I like very too much, and I wanted to explore how to execute application in an embedded board. I split that project in two articles. The first one is to explain two kind of encryption can be used for securing a channel between two devices and we are going to see the hardware I use for this project and how to generate random data.
Anatomy of the memory When we execute a program, each data are stored in the memory on the system. These data can be used by the program for doing stuff, for instance, if you program is a video game, some data of the game are stored in the memory. These data are temporary, because, when you close your program or shutdown your system, these data are destroyed. They are only used during the execution of the program.
Steganography The steganography is a domain which consist to hide data in other medias, such a document, a picture, a video, etc. It’s different from the cryptography, because, the cryptography consist to encrypt a plain-text message with a key and to have a cryptogram, which can be read by people who have only the key. I challenged myself and decided to made a project for hiding a message in a PNG file and to read it.
Encryption - Caesar cipher This first article is a part of a set of encryption articles and they do not have any professional purpose, but, just an exchange because the encryption is a part of science computing I like. I will talk about the Caesar cipher, the history behind this cipher, how to encrypt a plain-text message and how to decrypt it. Caesar cipher One of the first substitution cipher was used by Julius Caesar who was a Roman emperor and he develop a new cipher, called the Caesar cipher.
In nowdays, it’s really important for every engineers to keep their infrastructure secure for protecting the business and to avoid to be hacked. For system engineers, we have differents tools for doing an audit of their system. You have CIS, which give some best practices for Linux and Windows systems, or Lynis. These tools are powerful and useful, but, they do not matches my need. So, I created a specific project for auditing a Linux system.
Gravity - Projectile motion In this article, with no professional goal, but only to share my hobby regarding the astrophysics - the study of space and laws physics - I will share my program C for simulating the launch of a projectile on a planet. I am not an expert in this field, so, if I write something wrong, please contact me, and I will change my mistake. For simulating the motion, the program use two physics laws: the gravitation and the projectile motion, and we will see how it is works.
I am interested regarding the pentesting, so, I decided to write a set of articles regarding that field. In this first article, I will share with you how to do a reverse-engineering binaries with a simple C program and we will familiarize with the GNU debugger which is an important tool. How memory works In modern system, when an application is executed, the system allocate memory and each variables, functions and other components from the application is stored in the main memory.
In IT, specifically in IT security, the entropy’s system is very useful. This concept is very important for encryption and others applications using random data. Entropy are qualified like a data structure and represent the randomness in the system. For generating random datas, your system use many extern or intern factors: Disk interrupt Disk I/O Reading/writing time in disk Users interactions: mouse and keyboard Components RNG (Random Number Generator) etc. The RFC 4086(1) is very interesting, because, it give many solutions for generate the random data in the system, like using sound from microphone or using disk drive interrupts, but it given some examples of bad technicals for generate random data.
Sometimes, I need to create a laboratory with virtual machines or containers that I can set up easily for testing various technologies. I used to use UML, but this solution doesn’t address my requirements. In this article, we look at how to set up a laboratory, with systemd spawn for making containers. Making our first container To make our first container, we must use systemd, which allows us to manage services.