AES

What is AES (Advanced Encryption Standard) Encryption?

In short, AES is a symmetric type of encryption, as it uses the same key to both encrypt and decrypt data.

It also uses the SPN (substitution permutation network) algorithm, applying multiple rounds to encrypt data. These encryption rounds are the reason behind the impenetrability of AES, as there are far too many rounds to break through.

There are three lengths of AES encryption keys. Each key length has a different number of possible key combinations:

• 128-bit key length: 3.4 x 10³⁸
• 192-bit key length: 6.2 x 10⁵⁷
• 256-bit key length: 1.1 x 10⁷⁷

Even though the key length of this encryption method varies, its block size - 128-bits (or 16 bytes) - stays fixed.

The variety of key lengths poses some questions. Why are there multiple key lengths? And, if the 256-bit key is the strongest of the bunch (even referred to as “military-grade” encryption), why don’t we just always use it?

Well, it all comes down to resources. For example, an app that uses AES-256 instead of AES-128 might drain your phone battery a bit faster.

Luckily, current technology makes the resource difference so minuscule that there is simply no reason not to use 256-bit AES encryption.

The advantages of AES

Safety aside, AES encryption is very appealing to those who work with it. Why? Because the encryption process of AES is relatively easy to understand. This allows for easy implementation, as well as really fast encryption and decryption times.

In addition, AES requires less memory than many other types of encryption (like DES), which makes it a true winner when it comes to choosing your preferred encryption method.

Finally, when an action requires an extra layer of safety, you can combine AES with various security protocols like WPA2 or even other types of encryption like SSL.

Why do we use the AES algorithm?

Even if not exactly “ancient”, the advanced encryption standard is old.

Originally developed in 1998 by two Belgian cryptographers, Vincent Rijmen and Joan Daemen, AES has been around for more than 20 years. At first, it was referred to as Rijndael- a combination of the names of its developers.

Thanks to its impenetrability, AES encryption has already served as the encryption standard for 18 years. That’s because, in 2002, the National Institute of Standards and Technology (NIST) replaced the outdated Data Encryption Standard (DES) with AES.

Why did this happen?

Well, first of all, the DES key length was a mere 56 bits. And it turned out that this isn’t nearly enough to keep encrypted information safe. For example, a test by distributed.net and the Electronic Frontier Foundation showed that DES can be easily cracked in a little bit more than 22 hours. Keep in mind that this was done in 1999, when computing power was far from what it is now.

Today, a powerful machine can crack a 56-bit DES key in 362 seconds.

On the other hand, cracking a 128-bit AES encryption key can take up to 36 quadrillion years.

Just imagine what time it would take to crack a 256-bit AES key, which boasts a staggering number of 984,665,640,564,039,457,584,007,913,129,639,936 combinations. Keeping this number in mind, we can safely assume that a brute-force attack on AES encryption will not happen without a significant increase in computing power.

Where is the AES algorithm used?

With its humble beginnings as the go-to encryption cipher of the US government, AES encryption quickly took the world by storm, becoming the encryption standard for basically anything we see online. As a result, you will have trouble finding industries or services that don’t use the AES algorithm.

Online banking credentials, passwords, and messages all need to be protected from people who can do harm. So, aside from “serving” the government (like the National Security Agency), the advanced encryption standard protects the sensitive data of a myriad of products.

Examples of AES usage

Here are a few notable examples of where developers can use the AES encryption:

• VPNs (Virtual Private Networks). As the job of a VPN is to securely connect you to another server online, only the best methods of encryption can be considered so that your data wouldn’t leak. The VPNs that use the advanced encryption standard with 256-bit keys include NordVPN, Surfshark, and ExpressVPN.
• Wi-Fi. That’s right - wireless networks also use AES encryption (usually, together with WPA2). This is not the only type of encryption Wi-Fi networks can use, however, most of the other encryption methods are far less safe.
• Mobile applications. Many popular apps (like Snapchat and Facebook Messenger) use AES encryption in order to safely send info like photos and messages.
• Archive and compression tools. All major file compression programs use AES to prevent data from leaking. These tools include 7z, WinZip, and RAR.
• OS system components. Some operating system components (like file systems) use the advanced encryption standard for an extra layer of safety.
• Programming language libraries. The libraries of such coding languages like Java, Python, and C++ implement AES encryption.
• Password managers. These are the programs that carry a lotof sensitive information. That’s why password managers like LastPass and Dashlane don’t skip the important step of AES implementation.

Even though this is an impressive list of what AES encryption is useful for, it still doesn’t include everything.

Aside from all the things mentioned before, you will encounter the AES encryption algorithm in various file systems and disk encryption systems, as well as web browsers.

That’s right - you even used AES to open this article, as your browser must encrypt your connection with this page.

How does AES encryption work?

Here’s what you should know from the get-go: without the proper background, the AES encryption algorithm can be a tough one to understand. To fully appreciate its intricacies, you would probably have to be a maths major (at least).

Luckily, it is possible to simplify the inner workings of the AES cipher. Replacing the binary code with “normal” symbols is one way of doing it.