Serves as the initial round during encryption * AddRoundKey is simply an XOR of a 128-bit block with the 128-bit key. */

Used in Round() and serves as the final round during decryption * SubRoundKey is simply an XOR of a 128-bit block with the 128-bit key. * So basic

Implementing the algorithm

The main KeyExpansion function * Generates additional keys using the original key * Total of 11 128-bit keys generated, including the original *

Shift left, adds diffusion

Shifts rows right (rather than left) for decryption

Perform substitution to each of the 16 bytes * Uses S-box as lookup table */

Perform substitution to each of the 16 bytes * Uses inverse S-box as lookup table */

Function to compute xor between two strings

Function to compute xor between two strings

Function to convert a number in binary to decimal

Function to convert a number in binary to decimal

Hàm kiểm tra chuỗi nhị phân hợp lệ

picking a random prime number and erasing that prime number from list because p!=q

Function to compute base^expo mod m

Function to do a circular left shift by 1

Function to do a circular left shift by 1

Function to do a circular left shift by 2

Function to do a circular left shift by 2

The AES decryption function * Organizes all the decryption steps into one function */

The AES encryption function * Organizes the confusion and diffusion steps into one function */

Implementing the algorithm

decryption function

Encription function

Same as Round() except it doesn't mix columns

Same as Round() but no InverseMixColumns

InverseMixColumns uses mul9, mul11, mul13, mul14 look-up tables * Unmixes the columns by reversing the effect of MixColumns in encryption */

Auxiliary function for KeyExpansion

MixColumns uses mul2, mul3 look-up tables * Source of diffusion */

Each round operates on 128 bits at a time * The number of rounds is defined in AESEncrypt() */

Each round operates on 128 bits at a time * The number of rounds is defined in AESDecrypt() * Not surprisingly, the steps are the encryption steps

calculate entropy

Function to convert a number in decimal to binary

Function to convert a number in decimal to binary

to decrypt the given number

Decrypt message using private key (d, n)

Hàm mã hóa DES

first converting each character to its ASCII value and then encoding it then decoding the number to get the ASCII and converting it to character

This function receives text and shift and returns the encrypted text

This function receives text and shift and returns the encrypted text

to encrypt the given number

Encrypt message using public key (e, n)

Hàm mở rộng E

Function to return gcd of a and b

Returns gcd of a and b

Generate random key

RSA Key Generation

Hàm tạo subkey

Function to generate the 16 keys.

Function to generate the 16 keys.

Hàm hoán vị

Hàm kiểm tra số nguyên tố

Function to find modular inverse of e modulo phi(n) Here we are calculating phi(n) using Hit and Trial Method but we can optimize it using Extended Eu

Hàm hoán vị P

we will run the function only once to fill the set of prime numbers

Hàm S-box

Driver program to test the above function

Driver program to test the above function

Code to demonstrate RSA algorithm