Advanced Encryption Standard (AES)

What is the Advanced Encryption Standard (AES)?

Advanced Encryption Standard (AES) is an open source block cipher that uses symmetric encryption to transform sensitive information into ciphertext. The same secret key is used for both encryption (plaintext to ciphertext) and decryption (ciphertext back to plaintext).

Table of Contents Table of Contents

1. What is the Advanced Encryption Standard (AES)?
2. Key Takeaways
3. Why AES is the Gold Standard for Encryption
4. How Advanced Encryption Standard Works
5. Advantages and Disadvantages of AES Encryption
6. AES Use Cases
7. AES Security
8. Attacks on AES Encryption
9. Five Tips to Prevent Attacks on AES Encryption
10. How Does AES Compare to Other Encryption?
11. The Bottom Line
12. FAQs
13. References

Show Full Guide

Table of Contents

1. What is the Advanced Encryption Standard (AES)?
2. Key Takeaways
3. Why AES is the Gold Standard for Encryption
Show Full Guide
4. How Advanced Encryption Standard Works
5. Advantages and Disadvantages of AES Encryption
6. AES Use Cases
7. AES Security
8. Attacks on AES Encryption
9. Five Tips to Prevent Attacks on AES Encryption
10. How Does AES Compare to Other Encryption?
11. The Bottom Line
12. FAQs
13. References

Why AES is the Gold Standard for Encryption

In 1997, the National Institute of Standards and Technology (NIST) issued a public call for proposals to replace the Data Encryption Standard (DES), which had become vulnerable to brute-force attacks.

Five finalists were selected out of 15 initial submissions: RC6, MARS, Serpent, Twofish, and Rijndael. NIST officially announced that Rijndael would be the new standard for encryption in 2001. As part of the standardization process, the Rijndael algorithm was formally renamed “Advanced Encryption Standard” to reflect its new status as an international standard.

AES’s design iterates complex mathematical transformations (substitution, permutation, mixing, and key addition) multiple times, making it highly resistant to cryptanalysis attacks. AES is considered to be the gold standard because over the last two decades, the Advanced Encryption Standard has withstood extensive scrutiny from cryptographers worldwide, and nobody has been able to break it.

How Advanced Encryption Standard Works

AES starts with a single secret key that is either 128, 192, or 256 bits long.

The initial secret key is then transformed into a series of ’round keys,’ each of which is 128-bits. The round keys are derived iteratively from the original key by using a special key schedule algorithm. Essentially, the output of one round becomes the input of the next round, and this process continues until all rounds are completed.

The number of rounds depends on the key size (10 rounds for 128-bit keys, 12 for 192-bit keys, and 14 for 256-bit keys). Longer keys provide stronger security, but they also require more computational resources.

Advantages and Disadvantages of AES Encryption

In addition to being highly secure, the Advanced Encryption Standard is flexible. Since each block is encrypted independently, the process can be easily parallelized across multiple processors, which can significantly speed up encryption for large data sets.

Another advantage is that AES can be used with different modes of operation (e.g., cipher block chaining or Galois/Counter Mode). This adaptability makes it suitable for a wide range of use cases.

AES Use Cases

AES is used in a wide variety of scenarios to provide data confidentiality, integrity, and authenticity (CIA) for critical applications.

In addition to supporting full disk encryption, the Advanced Encryption Standard is used to encrypt:

• Data stored in the cloud.
• Communications between web browsers and servers.
• File transfers between systems.
• Network traffic over a VPN.
• Data stored on removable storage media.
• Credit card transactions.
• Official government records.
• Email messages and attachments.
• Password manager vaults (databases).
• Cryptocurrency wallets and mobile digital wallet transactions.
• Data exchanged between IoMT medical devices and hospital systems.
• Communication between Internet of Things (IoT) devices and cloud computing platforms.
• Copyrighted content in digital rights management systems.
• Data backups, whether stored locally or in the cloud.

AES Security

AES is highly secure when implemented properly. The strength of AES lies in its robust design, but its security can be compromised by poor implementation practices, such as improper key management, weak random number generation (RNG), or the misuse of encryption modes.

Attacks on AES Encryption

As of September 2024, there is no known type of cyberattack that can break AES when it’s implemented correctly. While theoretically, AES encryption could be broken with quantum computing, in the real world today AES attacks are not practical because they require an unrealistic amount of time and computational power to execute.

Five Tips to Prevent Attacks on AES Encryption

While AES itself is highly secure, it needs to be implemented correctly. Here are five ways to prevent attacks on AES encryption:

How Does AES Compare to Other Encryption?

While AES is useful for bulk encryption, it’s not the right tool for every task. For example, if you need to provide nonrepudiation, it can be useful to compare AES with other types of encryption.

The Bottom Line

Advanced Encryption Standard, by definition, is a symmetric block cipher that iteratively encrypts data in fixed-size 128-bit blocks. The standard is useful for encrypting data in bulk and supports different key lengths choices to balance an acceptable level of encryption strength with performance concerns.

FAQs