What Is AES Encryption? A Quick Breakdown

Last Updated on June 4, 2025 by Editorial

AES encryption is a method used to keep digital data safe by turning it into a scrambled code that only someone with the right initial key can read. It stands for Advanced Encryption Standard and is one of the most widely used ways to protect information today. Governments even use it for national security systems.

It works like a digital lock, turning plain text into unreadable code. Only someone with the right secret key can turn it back. It’s used in banking apps, Wi-Fi security, and password managers. Even the U.S. government trusts AES for classified data.

Today, it’s one of the safest encryption methods available. Cybersecurity experts trust it because no one has ever cracked it. That’s why AES is everywhere, protecting everything from emails to cloud data storage.

What Is Advanced Encryption Standard (AES)?

AES is a way to keep digital information safe. It scrambles electronic data so only the right person can read it. It works by turning readable data into an unreadable format using a special key. It processes data in blocks and applies several rounds of mixing and substitution. 

The number of rounds depends on the key length: 128-bit uses 10 rounds, 192-bit uses 12, and 256-bit uses 14. The longer the key, the harder it is to break.

This encryption method is fast, secure, and widely used. You’ll find AES in banking apps, virtual private networks, cloud storage, and even Wi-Fi security. Hackers would need billions of years to crack it using current technology. That’s why it’s a top choice for keeping information private.

The History of AES Encryption

Back in the ‘90s, the U.S. government needed a better way to keep confidential data safe. The old standard, DES (Data Encryption Standard), wasn’t cutting it anymore. Computers got faster, and hackers could crack DES way too quickly. So, in 1997, the National Institute of Standards and Technology (NIST) started looking for a new encryption method.

After a worldwide competition, two Belgian cryptographers, Vincent Rijmen and Joan Daemen, submitted an algorithm called Rijndael. It stood out because it was fast, secure, and worked well on different types of hardware. In 2001, NIST officially picked the Rijndael encryption and renamed it the Advanced Encryption Standard (AES). It became the new standard for government computer security.

Today, AES is used everywhere for data security. It’s been tested for over 20 years and still hasn’t been cracked. That’s why it remains the go-to choice for encryption worldwide.

AES Encryption Features

AES is a trusted encryption method. Let’s break down its key features and why it’s so effective.

• Strong Key Lengths: AES supports three different key lengths—128-bit, 192-bit, and 256-bit. The longer the key, the harder it is to crack. Even the shortest AES key is strong enough to protect against brute-force attacks. Most high-security systems use 256-bit encryption for extra protection.

• Block Cipher System: AES processes data in fixed-size blocks. Each block is 128 bits, meaning it encrypts information in chunks. This method is called cipher block chaining, and it helps keep data structured and secure. It also makes AES more efficient than older encryption methods.

• Multiple Encryption Rounds: AES encryption algorithm doesn’t just scramble data once. It does it multiple times using substitution, permutation, and mixing steps. The number of rounds depends on the key length: 10 rounds for 128-bit, 12 for 192-bit, and 14 for 256-bit. More rounds make it harder for attackers to break the encryption.

• Symmetric Encryption: For a symmetric encryption algorithm, AES uses the same key for encryption and decryption. That means both the sender and receiver need the same key. This makes AES on a symmetric block cipher faster than asymmetric encryption, which uses two separate keys.

• Resistant to Attacks: AES algorithm is built to protect against common attacks. It defends against brute force attacks, where hackers try every possible key. It’s also strong against differential and linear cryptanalysis, which are methods used to find patterns in encrypted data.

• Widely Used and Trusted: AES has been the official U.S. government encryption standard since 2001. Banks, businesses, and security apps around the world use it daily. Even Wi-Fi networks and password managers rely on AES to keep information safe.

• Fast and Efficient: AES algorithm works well on different devices, from small chips to large servers. It’s optimized for speed, so it encrypts data quickly without slowing things down. That’s why it’s perfect for real-time applications like video streaming and secure messaging.

Types of AES Encryption

AES comes in different types, each with its own way of handling encryption. Let’s go over them and where they’re used.

AES-128

AES-128 uses a 128-bit key to encrypt data. It goes through 10 rounds of encryption, making it strong and secure. This type is fast and works well for systems that need speed without losing security.

• Real-Life Use: Many payment systems use AES-128 to protect credit card details. It’s also common in secure messaging apps.

AES-192

AES-192 has a 192-bit key size and uses 12 encryption rounds. It offers a stronger defense than AES-128. It’s a good option for applications that need extra security.

• Real-Life Use: Government agencies use AES-192 for classified information. It’s also used in financial services to protect sensitive data.

AES-256

AES 256 bit is the strongest version, with a 256-bit key and 14 encryption rounds. It’s nearly impossible to break with current technology. This makes it the best choice for top-level security.

• Real-Life Use: Cloud storage providers use AES-256 to protect user data. It’s also used to secure communications for military systems as well as for secure data exchange. Wi-Fi networks use AES to keep connections safe. WPA2 and WPA3 security standards rely on AES encryption modes. This secures wireless networks, preventing hackers from stealing data. USB drives use AES to encrypt files and prevent unauthorized access

How AES Encryption Works

The AES encryption algorithm follows a unique process when protecting data. Here are the detailed steps..

• Step 1: Breaking Data Into Blocks – AES works with fixed-size blocks. Each block is 128 bits, which is 16 bytes. If the data is longer, it gets split into multiple blocks. If it’s shorter, padding is added to fill the space.

• Step 2: Expanding the Key – AES uses keys of 128, 192, or 256 bits. The key goes through a key expansion process. This creates multiple round keys from the original key. These round keys are used at different stages of encryption.

• Step 3: Adding the First Round Key – Before starting encryption, the first round key is applied to the data block. This step is called an XOR operation. It mixes the data with the key to add an extra layer of security.

• Step 4: Byte Data Substitution (SubBytes) – Each byte in the block is replaced with a different byte from a special lookup table. This step scrambles the data to make patterns harder to detect.

• Step 5: Shifting Rows (ShiftRows) – The second row of the block shifts left by one position. The third row shifts left by two. The fourth row shifts left by three. This spreads the data across the block.

• Step 6: Mixing Columns (MixColumns) – Each column in the block is mixed using a mathematical function. This step increases diffusion, making it harder to reconstruct the original data. AES-128 does this for nine rounds. AES-192 does it for eleven. AES-256 does it for thirteen.

• Step 7: Adding Another Round Key – A new round key is added to the data block using another XOR operation. This step strengthens encryption.

• Step 8: Repeating the Steps – The encryption process repeats for multiple rounds. AES-128 has 10 rounds. AES-192 has 12. AES 256 bit has 14. Each round makes the data harder to break.

• Step 9: Final Round (No Mixing Columns) – The last round skips the MixColumns step. Instead, it does SubBytes, ShiftRows, and AddRoundKey. This completes the encryption process.

• Step 10: Producing the Encrypted Output – After the last round, the block is fully encrypted. It looks like random data. Only the right key can decrypt data.

AES vs. DES

AES replaced DES because DES just couldn’t keep up with modern threats. DES uses a 56-bit key, which is too short and can be cracked in hours with enough computing power. AES, on the other hand, uses 128, 192, or 256-bit keys, making brute-force attacks nearly impossible. The switch to AES was all about keeping data safer as tech moved forward.

DES also works on smaller blocks, just 64 bits, while AES uses 128-bit blocks, which adds more strength. AES is also faster on most modern hardware, even though it’s doing more. DES just isn’t built for today’s needs, and its age shows. AES gives much stronger protection with better performance.

AES vs. RSA

AES and RSA are used for different things. AES is for fast, secure bulk encryption, while RSA is for sharing keys and verifying identity. AES is symmetric, meaning the same key is used to encrypt and decrypt. RSA is asymmetric, using a public key to encrypt and a private key to decrypt. That difference changes how they’re used in practice.

You wouldn’t use RSA to encrypt large files. It’s slow and better suited for small bits of data like session keys. In real-world systems, RSA often protects the AES key, and then AES handles the actual data. They’re not really in competition, they work together. Each has a job that plays to its strengths.

Can AES Encryption Be Hacked?

The AES cipher itself is considered unbreakable with today’s technology. No one has cracked it by brute force. A brute-force attack tries every possible key until one works. But AES-256 has more possible keys than there are atoms in the universe. It would take billions of years to guess the right one.

Still, like every other security system on the planet, AES-256 isn’t 100% foolproof. Let’s explore some potential threats.

Side-Channel Attacks

While the AES cipher remains secure, hackers sometimes attack the systems that use it. These are called side-channel attacks. They don’t target AES directly. Instead, they exploit hardware weaknesses, power usage, or timing differences.

One example is the 2017 Cache Timing Attack. Researchers showed that AES keys could be leaked from Intel CPUs. This attack worked by measuring how long encryption operations took. It didn’t break AES itself. It only worked on certain systems.

Key Theft and Weak Passwords

AES is only as strong as the key protecting it. If hackers steal an encryption key, they don’t need to break AES. Weak passwords or poor key storage can make it easier for attackers to get access. In 2013, Edward Snowden revealed that the NSA collected encrypted data. They couldn’t break AES, but they focused on weak keys and poor security practices.

Quantum Computing Risks

Quantum computers could pose a future threat. They use different math than regular computers. They might break some encryption methods faster. Right now, even the best quantum computers can’t break AES. But researchers are preparing for that possibility.

Related Key Attacks

Related-key attacks on AES 256 target patterns in how keys are expanded. Instead of breaking the cipher directly, attackers use two or more keys with known relationships to find shortcuts in the encryption.

AES-256 has a slightly weaker key schedule than AES-128, which opens a small crack for a related key attack. That said, these attacks aren’t practical yet. They need unrealistically huge amounts of electronic data and time.

Wrapping Up

With that, we have fully answered the question, what is AES encryption. This cipher has been the go-to security standard for over two decades, protecting everything from personal messages to government secrets. It’s never been cracked, and experts agree it will remain secure for years to come.

The biggest potential threat? Quantum computing. But even with future advancements, the AES 256 encryption is expected to hold strong. If you’re using a VPN, secure messaging app, or encrypted storage, AES encryption is working behind the scenes to keep your data safe.

What are your thoughts on AES encryption algorithms? Have questions? Drop a comment below and let’s discuss!

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