# How does AES algorithm work?

### Table of Contents

- How does AES algorithm work?
- What algorithm does AES use?
- What are the 4 steps of AES algorithm?
- Where AES algorithm is used?
- Why is RSA better than AES?
- Why AES algorithm is used?
- Is AES faster than RSA?
- What is difference between DES AES?
- How many subkeys are there in AES algorithm?
- Is AES free?
- How are encryption keys used in the AES algorithm?
- How many rounds does the AES algorithm take?
- How does the AES algorithm work in reverse order?
- How is data represented in an AES block?

### How does AES algorithm work?

The AES engine **encrypts the plain text (source data) into cipher text (encrypted data) and sends it to the NAND flash for storage**. Inversely, if the host wants to retrieve data from the storage device, the AES engine decrypts the cipher text in the NAND flash, and then transmits data to the host as plain text.

### What algorithm does AES use?

The algorithm described by AES is **a symmetric-key algorithm**, meaning the same key is used for both encrypting and decrypting the data. In the United States, AES was announced by the NIST as U.S. FIPS PUB 197 (FIPS 197) on Novem.

### What are the 4 steps of AES algorithm?

**Steps in the AES Encryption Process**

- Derive the set of round keys from the cipher key.
- Initialize the state array with the block data (plaintext).
- Add the initial round key to the starting state array.
- Perform nine rounds of state manipulation.
- Perform the tenth and final round of state manipulation.

### Where AES algorithm is used?

Where is AES used? AES encryption is commonly used in a lot of ways, including **wireless security, processor security, file encryption, and SSL/TLS**.

### Why is RSA better than AES?

Because there is no known method of calculating the prime factors of such large numbers, only the creator of the public key can also generate the private key required for decryption. **RSA is more computationally intensive than AES**, and much slower. It's normally used to encrypt only small amounts of data.

### Why AES algorithm is used?

The Advanced Encryption Standard (AES) is a **symmetric block cipher chosen by the U.S. government to protect classified information**. AES is implemented in software and hardware throughout the world to encrypt sensitive data. It is essential for government computer security, cybersecurity and electronic data protection.

### Is AES faster than RSA?

**RSA is more computationally intensive than AES**, and much slower. It's normally used to encrypt only small amounts of data.

### What is difference between DES AES?

AES stands for Advanced Encryption Standard. DES stands for Data Encryption Standard. Key length varies from 128 bits, **192 bits to 256 bits**. ... AES is de-facto world standard and is more secure than DES.

### How many subkeys are there in AES algorithm?

10 subkeys
Before encrypting, the 128 bit key is used to generate **10 subkeys** of 128 bits (16 bytes) each. The bytes of each subkey are written column-wise into a 4x4 matrix, giving ten such matrices.

### Is AES free?

AES is NIST-certified and is used by the US government for protecting "secure” data, which has led to a more general adoption of AES as the standard symmetric key cipher of choice by just about everyone. It is **an open standard that is free to use for any public, private, commercial, or non-commercial use**.

### How are encryption keys used in the AES algorithm?

Like nearly all encryption algorithms, AES relies on the use of keys during the encryption and decryption process. Since the AES algorithm is symmetric, the same key is used for both encryption and decryption (I will talk more about what this means in a moment).

### How many rounds does the AES algorithm take?

These are steps AES algorithm takes for each round. And after doing same things for X rounds (10 rounds for 128-bit key length, 12 rounds for 192-bit key length, 14 rounds for 256-bit key length), we can get ciphertext encrypted by AES algorithm.

### How does the AES algorithm work in reverse order?

This means that almost the same steps are performed to complete both encryption and decryption in reverse order. The AES algorithm operates on bytes, which makes it simpler to implement and explain. This key is expanded into individual sub keys, a sub keys for each operation round.

### How is data represented in an AES block?

Because AES is also block cipher, we first represent data such as plaintext, ciphertext and key as block. Each block has 1byte (8bit) so in total 16x8=128bit, notice that we have 128-bit key length. And as you can see the order of p_0, p_1 …, the data represented as column by column order.