Transposition cryptography

by Amir Sadeghian Posted on | Information Security

In the previous article, I review a brief history of ancient Cryptography and Steganography. In this article, we will explain more detail about the different techniques of cryptography. Cryptography methods can generally be divided into two types of Transposition and substitution. In transposition, the letters of the message are rearranged and produce the secret. This…

Introduction to Cryptography and Steganography

by Amir Sadeghian Posted on | Information Security

Cryptography is an interesting art. Bear with me and you will see. In this post, I will tell you a brief history of Cryptography and Steganography. The next post will be more technical. A long time ago ancient dynasties rely on different methods of communication in their region. They always were interested in new methods…

Network Address Translation (NAT)

by Amir Sadeghian Posted on | Information Security

Public IP addresses are rare to find, especially classes A, B & C. Recently IP version 6 introduced to address this problem. However IPV6 adoption is slow and can’t practically be helpful in the near future. To address this problem network administrators usually use private IP addresses on local networks. Private IP addresses allow computers…

Domain Name Service (DNS) & DNS Security

by Amir Sadeghian Posted on | Information Security

In the previous lesson, we discussed IP addresses. Remembering the IP addresses is difficult. It’s not easy to remember all the IP addresses that we need for our daily use. Domain name service (DNS) allows us to use “easy to remember” names instead of memorizing IP addresses. For instance, instead of remembering we can use  DNS is…

Network Ports

by Amir Sadeghian Posted on | Information Security

As we learned in the previous lesson, IP addresses uniquely identify computers. Most of the times each computer has more than one service. For instance, a computer can be a web server and a file server at the same time. For addressing this in addition to having a unique IP address we have a unique PORT…

TCP IP Networking Basics

by Amir Sadeghian Posted on | Information Security

Basically, computers are connected to each other through networks, we can divide the networks into two main categories of : LAN (Local Area Networks): LAN networks used for connecting computers in limited areas such as an office, a building or schools. WAN (Wide Area Networks): WAN networks connect LAN networks to each other. The most…

Information Security Key Principles (CIA Triangle)

by Amir Sadeghian Posted on | Information Security

Information security has three main principles which are come in the form of the CIA model which is also known as CIA triad (Triangle). Each letter of the CIA represents one of the three principles of information security. These principles are: Confidentiality In an easy definition it means “Keep the private information PRIVATE” and avoid disclosure of it…

Light Youtube Embed

by Amir Sadeghian Posted on | Javascript

As part of my daily job, I deal with many clients that have their own YouTube channel and use this powerful service for hosting their videos. Clients want to embed their videos on their website. Sometimes they want many videos on the same page.YouTube uses iframe for allowing users to embed videos on their websites….

GoLang Dice Project

by Amir Sadeghian Posted on | Golang

The main goal of this project is to make you more familiar with random in Go programming language. In this project you are going to practice your knowledge in the following topics: If else condition Function definition, function parameter Unix time Random Println To generate a random number in Go, rand from math need to…