Across every industry and application, the Advanced Encrypted Standard (AES) is the top choice for data encryption.
So what is AES encryption? Let’s unravel what it is, how it works, and why it’s the preferred encryption algorithm.
What Is the Advanced Encryption Standard (AES)?
The acronym AES means Advanced Encryption Standard. Adopted by the National Institute of Standards and Technology (NIST) in 2001, it’s the most secure encryption standard for modern data protection.
Definition: AES
The Advanced Encryption Standard (AES) is a symmetric key encryption method for securing data. Every key encryption process masks readable content, but symmetric key encryptions use the same key for both encryption and decryption.
More specifically, AES is a block cipher: a type of symmetric key encryption that translates readable data into fixed-size blocks. All AES encryption features 128-bit block sizes with varying cryptographic key lengths.
The 3 Types of AES Encryption: Key Features
The root AES algorithm is called Rijndael, but there are three unique instantiations, or types of AES encryption.
Simple and Fast: AES-128 Encryption
With a 128-bit key (16 bytes) and 10 encryption rounds, AES-128 is suitable for most data security needs. Speed slightly outweighs security, making AES-128 ideal for low-risk activities requiring efficient data transmission.
Balanced: AES-192 Encryption
This 192-bit key encryption (24 bytes) delivers a balance of reasonable speeds and advanced security. While slower than AES-128, itproduces more heavily encrypted data thanks to its 12 rounds of encryption
Robust and Complex: AES-256 Encryption
AES-256 provides the most advanced level of encryption, with a 256-bit key (32 bytes) and14 encryption rounds. It’s ideal for highly sensitive dataWhile you lose computational speed, you gain protection.
Similarities and Differences: AES-128 vs. AES-192 vs. AES-256
Similarities between each AES type:
- Encryption Type: All block ciphers with symmetric encryption, using advanced substitution and permutation to obscure data and resist attacks
- Same Algorithm: All use the Rijndael symmetric encryption algorithm
- Block Size: All 128-bit block sizes
Differences:
- Level of Encryption (Key Lengths and Encryption Rounds): 128 bits with 10 rounds of encryption, 192 bits with 12 rounds, and 256 bits with 14 rounds, respectively
- Computational Speed: More levels of encryption require additional resources, slowing speeds
- Specific Transformations: With varying key lengths and encryption rounds, the types and frequencies of data transformations differ, too
How Does AES Work?
AES works by carrying out encryption in four key phases, as follows.
Phase 1: Key Expansion
Upon key generation, the initial encryption key expands into a number of round keys (arrays of four words used as inputs during encryption), creating a key schedule algorithm based on the number of expansion rounds in your AES type.
Phase 2: Encryption Process
The encryption process includes four key processes:
- Round Key Addition (AddRoundKey): The readable plaintext data combines with the first round key to begin the encryption.
- Byte Substitution (SubBytes): A substitution box (S-box) replaces each existing byte with a corresponding byte, obscuring linear logic.
- Row Shifting (ShiftRows): Data rows shift to the left by one, two, or three bytes.
- Column Mixing (MixColumns): All data columns scramble using a complex mathematical operation.
Phase 3: Repeat (Multiple Rounds)
During this stage, the AES tools repeat the steps in Phase 2, using subsequent round keys, until completing the penultimate encryption round (round 9 for AES-128, 11 for AES-192, or 13 for AES-256).
Phase 4: Final Round
During phase 4, the AES tool performs its final round of encryption. This is a slightly different process; the tool performs the first three steps of encryption, but leaves out the Column Mixing, or MixColumn step.
What Is AES Used For? Real-Life Examples
AES protects classified information and other confidential data from cyber threats, including brute-force attacks. Here are common AES applications in current technology.
- Wireless Security: Wireless AES encryption such as WPA2 and WPA3 (WiFi Protected Access 2 and 3) keeps data transfers secure over wireless networks. It’s commonly used for home and business WiFi networks, and for Internet of Things (IoT) devices.
- Hypertext Transfer Protocol Secure (HTTPS): HTTPS uses AES encryption to create an additional security layer, protecting sensitive information between the browser and server. HTTPS delivers greater protection than standard HTTP and is used by website administrators across most industries.
- Secure Communication on Apps and Software: AES applications provide Aaudio and video encryption for secure virtual calls using Voice Over IP (VOIP). Encrypted communications are used by military, government, and national security systems, along with consumer-facing messaging apps and email services.
- Virtual Private Networks (VPNs): Private internet networks use AES encryption to restrict access to internal content and secret information. Remote and hybrid companies across industries use this technology to protect their data
- Secure Storage to Encrypt Files on Devices, Disks, and Databases: AES tools provide private disk encryption and encryption for personal devices, cloud storage, backups, and more. These applications are used alongside other security measures, such as Dynamic PKI validation, to protect sensitive data like medical records and legal documents.
- Payment Processing and Financial Transactions: AES encryption protects confidential data for payment and financial records. Financial institutions including banks, blockchain, and cryptocurrency companies, along with e-commerce and Point of Sale (POS) tools, rely on these encryption tools.
- Password Managers: AES encryption delivers tobust protection for stored login credentials. Trusted tools such as LastPass rely on AES to protect passwords for business and personal use.
- Passwordless Authentication: Encrypted certificate-based authentication bypasses the risk of stolen passwords. Microsoft recommends this approach for WiFi and VPNs in particular.
AES vs. Other Encryption Algorithms
What makes AES the gold standard? The balance of flexibility, speed, and robust security. Here’s how it compares to other encryption tools.
AES vs. RSA
AES is a symmetric block cipher with shorter key lengths for higher speeds; it uses the same key for encrypting and decrypting data blocks.
The Rivest-Shamir-Adleman (RSA) algorithm is asymmetric with longer key sizes (4096 bits) producing slower speeds; it uses different public and private keys.
AES vs. DES
AES offers a 128-bit block size with substantial key length options (128, 192, 256) for reliable protection and speed.
In contrast the Data Encryption Standard (DES) is just 64 bits with a 56-bit key size, creating vulnerabilities against brute-force and other cryptographic attacks.
Advantages and Risks: How to Prevent Attacks on AES Encryption
Protect your encrypted data by properly balancing the risks and advantages of AES.
- It’s Secure, Not Impenetrable: While highly secure compared to other encryption methods, AES keys aren’t attack-proof. Anticipate brute-force, side-channel, and related key attacks, including quantum computing algorithms.
- There’s a Learning Curve: Complexity is an advantage against attacks, but mistakes compromise security. Trained staff can keep AES secure and error-free.
- Strong Key Management Practices Are Critical: If attackers access your keys, they can quickly decrypt all the data. Never reuse secret keys.
- Advanced Randomizing Required: Without true randomization, attackers can spot patterns. Don’t rely on basic random number generators to protect data.
With a clear understanding of AES encryption, you’re a step closer to keeping company data safe and secure.
