AES Basics and MATLAB code

AES stands for Advanced Encryption Standard. It is basically encryption decryption algorithm for data. Encryption converts raw input data into encrypted data. Decryption does the reverse. AES supports keys of length 128, 192 and 256 bits. This cryptographic key is used to encrypt and decrypt data which is in blocks of 128 bits in length.

The 128 bit AES algorithm is in use everywhere to protect the electronic transactions. The AES core designed by companies contain both Encryption and Decryption modules which can run on single core. Typically AES IP Core supports two modes viz. OFB and CTR (i.e. counter) mode.

CTR MODE stands for Counter mode. In this type of mode following steps are implemented in encryption process. 1. Input to the encryption core is output of counter. Initialization vector is needed for counter. 2. XOR of input data and output of encryption module is performed. This XORed data is the cyphertext data which is encrypted one. Following steps similar to encryption is performed in decryption process. 1. Output of the counter is taken as input. Initialization vector same as used in encryption need to be employed. 2. Input data is then encrypted by XOR operation with output of the encryption core module. This operation gives out original data.

OFB means Output Feed Back Mode. In this type of mode, output of the encryption operation is fed back to the input of the encryption Core. An initialization vector is used for the first iteration. The input data is encrypted by XOR operation with output of encryption module.

AES is widely used in Wireless communication,Electronic financial transactions,Secure communications, secure video surveillance systems ,Encrypted data storage and e-Business applications.

Refer AES vs DES page to learn difference between AES and DES.

Download AES MATLAB code

AES MATLAB code files

Download DES MATLAB code

DES MATLAB code files

Useful Links to MATLAB codes

Refer following as well as links mentioned on left side panel for useful MATLAB codes.
PTS for PAPR reduction
OFDM Preamble generation
Time off estimation corr
Freq off estimation corr
channel estimation
11a WLAN channel
11g WLAN channel
15.3 UWB channel
15.4a UWB channel
16d SUI Channel
16e wimax channel
Rician channel
Rayleigh channel
SC-FDMA
PN sequence generation
3D plotting
AM FM PM modulation
OFDMA Tx Rx
AES DES
carrier aggregation
CCDF
FIR Filter
IIR Filter
Low Pass FIR
Viterbi decoder
CRC8 CRC32

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