Hill Cipher in C and C++ (Encryption and Decryption) Archives

Here you get encryption and decryption program for hill cipher in C and C++. What is Hill Cipher? In cryptography (field identified with encryption-decryption) hill cypher is a polygraphic cipher dependent on a direct variable based math. Imagined by Lester S. Hill in 1929 and in this manner got its name. It was the principal cipher that had the option to work on 3 images without a moment's delay. Encryption: The given message string and the key string is spoken to as a framework. At that point key and message, framework are increased. At long last modulo 26 is taken for every component of the network got by the increase. The key framework that we take here ought to be invertible, generally, decryption won't be conceivable. Decryption: The scrambled message lattice is increased by the converse of key framework lastly its modulo 26 is taken to get the first message. Hill Cipher Program in C #include #include float encrypt[3][1], decrypt[3][1], a[3][3], b[3][3], mes[3][1], c[3][3]; void encryption(); //encrypts the message void decryption(); //decrypts the message void getKeyMessage(); //gets key and message from user void inverse(); //finds inverse of key matrix void main() { getKeyMessage(); encryption(); decryption(); } void encryption() { int i, j, k; for(i = 0; i < 3; i++) for(j = 0; j < 1; j++) for(k = 0; k < 3; k++) encrypt[i][j] = encrypt[i][j] + a[i][k] * mes[k][j]; printf("\nEncrypted string is: "); for(i = 0; i < 3; i++) printf("%c", (char)(fmod(encrypt[i][0], 26) + 97)); } void decryption() { int i, j, k; inverse(); for(i = 0; i < 3; i++) for(j = 0; j < 1; j++) for(k = 0; k < 3; k++) decrypt[i][j] = decrypt[i][j] + b[i][k] * encrypt[k][j]; printf("\nDecrypted string is: "); for(i = 0; i < 3; i++) printf("%c", (char)(fmod(decrypt[i][0], 26) + 97)); printf("\n"); } void getKeyMessage() { int i, j; char msg[3]; printf("Enter 3x3 matrix for key (It should be inversible):\n"); for(i = 0; i < 3; i++) for(j = 0; j < 3; j++) { scanf("%f", &a[i][j]); c[i][j] = a[i][j]; } printf("\nEnter a 3 letter string: "); scanf("%s", msg); for(i = 0; i < 3; i++) mes[i][0] = msg[i] - 97; } void inverse() { int i, j, k; float p, q; for(i = 0; i < 3; i++) for(j = 0; j < 3; j++) { if(i == j) b[i][j]=1; else b[i][j]=0; } for(k = 0; k < 3; k++) { for(i = 0; i < 3; i++) { p = c[i][k]; q = c[k][k]; for(j = 0; j #include using namespace std; float encrypt[3][1], decrypt[3][1], a[3][3], b[3][3], mes[3][1], c[3][3]; void encryption(); //encrypts the message void decryption(); //decrypts the message void getKeyMessage(); //gets key and message from user void inverse(); //finds inverse of key matrix int main() { getKeyMessage(); encryption(); decryption(); } void encryption() { int i, j, k; for(i = 0; i < 3; i++) for(j = 0; j < 1; j++) for(k = 0; k < 3; k++) encrypt[i][j] = encrypt[i][j] + a[i][k] * mes[k][j]; cout<<"\nEncrypted string is: "; for(i = 0; i < 3; i++) cout<<(char)(fmod(encrypt[i][0], 26) + 97); } void decryption() { int i, j, k; inverse(); for(i = 0; i < 3; i++) for(j = 0; j >a[i][j]; c[i][j] = a[i][j]; } cout >msg; for(i = 0; i < 3; i++) mes[i][0] = msg[i] - 97; } void inverse() { int i, j, k; float p, q; for(i = 0; i < 3; i++) for(j = 0; j < 3; j++) { if(i == j) b[i][j]=1; else b[i][j]=0; } for(k = 0; k < 3; k++) { for(i = 0; i < 3; i++) { p = c[i][k]; q = c[k][k]; for(j = 0; j < 3; j++) { if(i != k) { c[i][j] = c[i][j]*q - p*c[k][j]; b[i][j] = b[i][j]*q - p*b[k][j]; } } } } for(i = 0; i < 3; i++) for(j = 0; j < 3; j++) b[i][j] = b[i][j] / c[i][i]; cout<<"\n\nInverse Matrix is:\n"; for(i = 0; i < 3; i++) { for(j = 0; j < 3; j++) cout<<b[i][j]<<" "; cout<<"\n"; } } Output if you want to know more about that please watch this video Remark beneath in the event that you have any inquiries identified with the above program for hill cipher in C and C++.