AES takes an input of 128 bits, grouped into 16 bytes of 8 bits. Enter your 128 bits below in hexadecimal format.

Plaintext (in hex):

Encryption key (in hex):

These 16 bytes are then arranged into a 4 x 4 matrix. From this matrix we will do the 10 rounds of the AES algorithm (if the key has 192 bits, it's 12 rounds, and when the key has 256 bits, it's 14 rounds). Each round has 4 steps, Byte Substitution, Row Shifting, Column Mixing, then adding the Key for that round.

Perform Key ExpansionPerform Complete Encryption

Round 1 The SubByte transformation is the first step of each round. Each byte in our matrix is substituted with another value. The other value comes from what we call the S-Box.

Initial Populate the Matrix
Add Round Key Encrypt from here
Round 1 Perform SubBytes Step Encrypt from here
Perform ShiftRows Step Encrypt from here
Perform MixColumns Step Encrypt from here
Perform AddRoundKey Step Encrypt from here
Round 2 Perform SubBytes Step Encrypt from here
Perform ShiftRows Step Encrypt from here
Perform MixColumns Step Encrypt from here
Perform AddRoundKey Step Encrypt from here
Round 3 Perform SubBytes Step Encrypt from here
Perform ShiftRows Step Encrypt from here
Perform MixColumns Step Encrypt from here
Perform AddRoundKey Step Encrypt from here
Round 4 Perform SubBytes Step Encrypt from here
Perform ShiftRows Step Encrypt from here
Perform MixColumns Step Encrypt from here
Perform AddRoundKey Step Encrypt from here
Round 5 Perform SubBytes Step Encrypt from here
Perform ShiftRows Step Encrypt from here
Perform MixColumns Step Encrypt from here
Perform AddRoundKey Step Encrypt from here
Round 6 Perform SubBytes Step Encrypt from here
Perform ShiftRows Step Encrypt from here
Perform MixColumns Step Encrypt from here
Perform AddRoundKey Step Encrypt from here
Round 7 Perform SubBytes Step Encrypt from here
Perform ShiftRows Step Encrypt from here
Perform MixColumns Step Encrypt from here
Perform AddRoundKey Step Encrypt from here
Round 8 Perform SubBytes Step Encrypt from here
Perform ShiftRows Step Encrypt from here
Perform MixColumns Step Encrypt from here
Perform AddRoundKey Step Encrypt from here
Round 9 Perform SubBytes Step Encrypt from here
Perform ShiftRows Step Encrypt from here
Perform MixColumns Step Encrypt from here
Perform AddRoundKey Step Encrypt from here
Round 10 Perform SubBytes Step Encrypt from here
Perform ShiftRows Step
The MixColumn step is left out of the last round
Perform AddRoundKey Step	Output:

References:

• Dr. Scott Craver's Introduction to Cryptography and Information Security class, EECE 405 at Binghamton University
• http://en.wikipedia.org/wiki/Finite_field_arithmetic#Multiplication
• http://people.eku.edu/styere/Encrypt/JS-AES.html
• https://engineering.purdue.edu/kak/compsec/NewLectures/Lecture8.pdf
• http://www.cs.bc.edu/~straubin/cs381-05/blockciphers/rijndael_ingles2004.swf
• http://en.wikipedia.org/wiki/Advanced_Encryption_Standard

Output: