The Virginia cipher is encrypted in plaintext as helloeverybodygoodafternoon,key as how are you ,corresponding ciphertext as ?

C++ Programming the Virginia Cipher

Programming the Virginia Cipher

Requirements: The user can enter the key

#include

using namespace std;

#define MINCHAR 32

# define CHARSUM 94

char table[CHARSUM][CHARSUM];

bool Init();

bool Encode(char* key, char* source, char* dest);

bool Dncode(char* key, char* source, char* dest);

int main()

{

if(!Init())

{

cout << "Initialization error!" << endl;

return 1;

}

char key[256];

char str1[256];

char str2[256];

int operation;

while (1)

{

do

{

cout << "Please choose an operation: 1. encrypt; 2. decrypt; -1. exit\n";

cin >> operation;

}while(operation ! = -1 && operation ! = 1 && operation ! = 2);

if(operation == -1)

return 0;

else if(operation == 1)//encryption

{

cout << "Please enter the key:";

cin >>. key;

cout << "Please enter the string to be encrypted:";

cin >> str1;

Encode(key, str1, str2);

cout << "Encrypted string:" << str2 & lt;< endl;

}

else if(operation == 2)//decrypt

{

cout << "Please enter the key:";

cin >> key;

cout << "Please Enter the string to be decrypted:";

cin >> str1;

Dncode(key, str1, str2);

cout << "Decrypted string:" << str2 << endl;

}

< p>cout << endl;

}

return 0;

}

// Initialize Virginia Square

bool Init()

{

int i, j;

for(i = 0; i <. CHARSUM; i++)

{

for(j = 0; j < CHARSUM; j++)

{

table[j] = MINCHAR + (i + j) % CHARSUM;

}

}

Return true;

}

// Encryption

// key: key

// source: string to be encrypted

// dest: encrypted string

bool Encode(char* key, char* source, char* dest)

bool Encode(char* key, char* source, char* dest)

bool Encode(char* key, char* source, char* dest) dest)

{

char* tempSource = source;

char* tempKey = key;

char* tempDest = dest;

do

{

*tempDest = table[(*tempKey) - MINCHAR][(*tempSource) - MINCHAR];

tempDest++;

if(! (*(++tempKey)))

tempKey = key;

}while(*tempSource++);

dest[strlen(source)] = 0;

return true;

}

// Decryption

// key: the key

// source: the string to be decrypted

// dest: the decrypted string

bool Dncode(char* key, char* source, char* dest)

{

char* tempSource = source;

char* tempKey = key;

char* tempDest = dest;

char offset;

do

{

offset = (*tempSource) - (*tempKey);

offset = offset >= 0 ? offset : offset + CHARSUM;

*tempDest = MINCHAR + offset;

tempDest++;

if(! (*(++tempKey)))

tempKey = key;

}while(*++tempSource);

dest[strlen(source)] = 0;

return true;

}