Vigenere Cipher in C and C++ Archives

In this instructional exercise, you will find out about vigenere cipher in C and C++ for encryption and decryption. Vigenere Cipher is somewhat polyalphabetic substitution strategy. It is utilized for encryption of alphabetic content. For encryption and decryption, Vigenere Cipher Table is utilized in which letters in order from start to finish are written in 26 lines. Vigenere Cipher Encryption Message Text: JUSTTECHREVIEW Key: HELLO Here we need to acquire another key by rehashing the given key till its length become equivalent to unique message length. New Generated Key: HELLOHELLOHELLOHEL For encryption take the first letter of message and new key for example T and H. Take the letters in order in Vigenere Cipher Table where T line and H section harmonizes for example A. Rehash a similar procedure for every single outstanding letter set in the message content. At long last the encoded message content is: Encoded Message: ALPNFHDJAFVKCLATIC The calculation can be communicated in arithmetical structure as given underneath. The cipher content can be created by underneath condition. Ei = (Pi + Ki) mod 26 Here P is plain content and K is vital. Vigenere Cipher Decryption Encoded Message: ALPNFHDJAFVKCLATIC Key: HELLO New Generated Key: HELLOHELLOHELLOHEL Take first letters in order of scrambled message and produced a key, for example, An and H. Break down Vigenere Cipher Table, search for letters in order An in segment H, the comparing line will be the primary letters in order of unique message for example T. Rehash a similar procedure for every one of the letters in order in the encoded message. Unique Message: JUSTTECHREVIEW The above procedure can be spoken to in arithmetical structure by the following condition. Pi = (Ei – Ki + 26) mod 26 We will use the above arithmetical conditions in the program. Program for Vigenere Cipher in C #include #include int main(){ char msg[] = "JUSTTECHREVIEW"; char key[] = "HELLO"; int msgLen = strlen(msg), keyLen = strlen(key), i, j; char newKey[msgLen], encryptedMsg[msgLen], decryptedMsg[msgLen]; //generating new key for(i = 0, j = 0; i < msgLen; ++i, ++j){ if(j == keyLen) j = 0; newKey[i] = key[j]; } newKey[i] = '\0'; //encryption for(i = 0; i < msgLen; ++i) encryptedMsg[i] = ((msg[i] + newKey[i]) % 26) + 'A'; encryptedMsg[i] = '\0'; //decryption for(i = 0; i < msgLen; ++i) decryptedMsg[i] = (((encryptedMsg[i] - newKey[i]) + 26) % 26) + 'A'; decryptedMsg[i] = '\0'; printf("Original Message: %s", msg); printf("\nKey: %s", key); printf("\nNew Generated Key: %s", newKey); printf("\nEncrypted Message: %s", encryptedMsg); printf("\nDecrypted Message: %s", decryptedMsg); return 0; } Output Original Message: JUSTTECHREVIEW Key: HELLO New Generated Key: HELLOHELLOHELLOHEL Encrypted Message: ALPNFHDJAFVKCLATIC Decrypted Message: JUSTTECHREVIEW Program for Vigenere Cipher in C++ #include #include using namespace std; int main(){ char msg[] = "JUSTTECHREVIEW"; char key[] = "HELLO"; int msgLen = strlen(msg), keyLen = strlen(key), i, j; char newKey[msgLen], encryptedMsg[msgLen], decryptedMsg[msgLen]; //generating new key for(i = 0, j = 0; i < msgLen; ++i, ++j){ if(j == keyLen) j = 0; newKey[i] = key[j]; } newKey[i] = '\0'; //encryption for(i = 0; i < msgLen; ++i) encryptedMsg[i] = ((msg[i] + newKey[i]) % 26) + 'A'; encryptedMsg[i] = '\0'; //decryption for(i = 0; i < msgLen; ++i) decryptedMsg[i] = (((encryptedMsg[i] - newKey[i]) + 26) % 26) + 'A'; decryptedMsg[i] = '\0'; cout<<"Original Message: "<<msg; cout<<"\nKey: "<<key; cout<<"\nNew Generated Key: "<<newKey; cout<<"\nEncrypted Message: "<<encryptedMsg; cout<<"\nDecrypted Message: "<<decryptedMsg; return 0; } Remark beneath on the off chance that you have questions or discovered anything inaccurate in above instructional exercise for vigenere cipher in C and C++.