Advanced Encryption Standard (AES) 101

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May <00pam5>23</00pam5>, <00pam5>2022</00pam5>

The Advanced Encryption Standard (AES) is the most popular and widely used code/cipher/algorithm that companies which have an online presence employ to ensure the security of all online information.  Most of the online world today; companies, big and small, rely on AES to secure their online data. 

This post is a beginner's guide to AES; a simplistic, non-technical explanation of a rather highly technical topic.  What is AES?  How it works and what are its features? And how do we apply it in our daily online activities? All of this will be covered in this Guide. 

So let's begin the AES 101.

What is AES?

The Advanced Encryption Standard (AES) is an encryption method that uses the block cipher algorithm to protect your online information from all kinds of threats.  AES is recognized as the most effective and most popular encryption tool against growing data breaches.  Companies like Google, Facebook, Amazon, and Apple, use AES to protect their online data.  AES is also called Rijndael. 

Brief History of AES

Before AES, there was another encryption system called Data Encryption System (DES) developed by IBM and standardized by the American National Bureau of Standards. This system was implemented in 1970 and served the internet world for more than two decades; until the security experts of the mid-90s realized that the encryption system was prone to data leaks and hacks.

The vulnerability of DES was evident to the public when an organization of ethical hacking publicly hacked into the DES in less than 24 hours. It was an end to over two decades of DES dominance as a standard encryption protocol. 

It took 5 years after this event to recognize an encryption system as a standard. What took so much time is another long story, but let's summarize the story here to have the know-how of the background.   As a result, DES was not a standard encryption system anymore. The American National Institute of Standards and Technology then sought encryption models from all the big companies in the world at that time including IBM, Towfish, Rijndael, RSA Security, and Serpent. 

The evaluation process of each design was extensive and rigorous. This evaluation included real-time attack assessments, discussions and arguments, and quality tests. Only after 5 years of strenuous testing procedures, Rijndael was chosen as the best encryption system among its competitors.  Rijndael was later named to AES after standardization. 

The name Rijndael is derived from the names of its two Belgian designers; Vincent Rijmen and Joan Daemen.

How does AES work?

The operation of AES is based on a cipher/code that comes from a group of ciphers called 'block ciphers.' Basically, the operation of AES comprises a series of operations such as permutation and substitution.

As we know, any type of data, be it in text, audio, image or video form is transferred in the form of data packets which are called bits.  The basic unit of data is called a bit while 8 bits combine to form a byte. All the computational operations in AES are performed on the byte level.  During AES operation, data is divided into blocks of 16 bytes and each block is further arranged in the form of a 4×4 Matrix.  There is a variable number of computational rounds in the AES and the number of rounds depends on the size of the key.

The key is a specific code which the AES uses to encrypt the data. The same key is used to decrypt the encrypted data as the AES has a symmetric algorithm.  The AES has three key sizes; 128-bit, 192-bit, and 256-bit. There are 10 rounds, 12 rounds, and 14 rounds of respective computational rounds for each key size. 

Applications of AES

The popularity of AES continued to grow after its standardization and the quality tests continued to prove AES as the top Encryption system of all time. In 2003, the National Security Commission of the United States rated AES as suitable to secure top secret information. AES is a free security tool which any public or private organization of any type and size can use for their online security. Currently, AES is being used in a wide array of applications, some of which we will mention here for your information: 

►  VPNs

Virtual Private Networks (VPNs) are a tool with which you can access internet anonymously. VPNs hide your real identity and location, thus allowing you to use public networks without fearing about data or information security. 
The top VPNs of today such as NordVPN and ExpressVPN use AES encryption in their operations.  It is important to note here that not all VPNs use AES. So, if you are using a VPN, make sure that you are using one that incorporates AES. 


►  Data Compression Tools

While sharing files over the internet, it happens to us more often that the file size becomes a problem in downloading or uploading. File compression is a method by which we can reduce the original size of the file to a reduced size; thus making it easier to share. Data compression is also useful in saving the disk space in our devices. The tools, programs, and software that are used for data compression use AES. 

►  Encryption Tools

To ensure the security of personal data in our devices, we have many encryption tools available such as FileVault and BitLocker. These tools encrypt the data so that an irrelevant person is not able to access the data without our permission.  Most of these encryption tools use AES in their operation.


While the internet continues to make our lives easier, threats to our online information and data are growing more than ever.  In situations such as these, knowing about internet security tools and their features are very important as they can be employed effectively in order to keep ourselves safe from prevailing cyber attacks. 

We really hope that this beginner's guide on Advanced Encryption Standard (AES) has added to your information about the most important online security tool of modern time.  

AES is not only the safest encryption tool of the present, but it will also remain in the game for quite some time. So, now that you know about it a bit, you can use it in an effective manner to maximize your data security.