C和C ++中的Hill密码（加密和解密）

た入场券 2022-12-07 14:00 178阅读 0赞

Here you get encryption and decryption program for hill cipher in C and C++.

在这里，您将获得C和C ++中适用于Hill密码的加密和解密程序。

**What is Hill Cipher?**

**什么是希尔密码？**

In cryptography (field related to encryption-decryption) hill cipher is a polygraphic cipher based on linear algebra. Invented by Lester S. Hill in 1929 and thus got it’s name. It was the first cipher that was able to operate on 3 symbols at once.

在密码术(与加密-解密有关的领域)中，希尔密码是一种基于线性代数的多态密码。 由Lester S. Hill于1929年发明，因此得名。 这是第一个能够同时处理3个符号的密码。

**Also Read: [Caesar Cipher in C and C++ \[Encryption & Decryption\]][Caesar Cipher in C and C_ _Encryption _ Decryption]**

**另请阅读： [C和C ++中的Caesar密码\[加密和解密\]][Caesar Cipher in C and C_ _Encryption _ Decryption]**

**Encryption:** The given message string and key string is represented in the form of matrix. Then key and message matrix are multiplied. Finally modulo 26 is taken for each element of matrix obtained by multiplication. The key matrix that we take here should be invertible, otherwise decryption will not be possible.

**加密：**给定的消息字符串和密钥字符串以矩阵形式表示。 然后将密钥和消息矩阵相乘。 最后，对通过乘法获得的矩阵的每个元素取模26。 我们在这里采用的密钥矩阵应该是可逆的，否则将无法解密。

**Decryption: **The encrypted message matrix is multiplied by the inverse of key matrix and finally its modulo 26 is taken to get the original message.

**解密：**将加密的消息矩阵乘以密钥矩阵的逆，最后取其模26为原始消息。

To learn more about hill cipher you can visit following link.

要了解有关山密码的更多信息，请访问以下链接。

[https://en.wikipedia.org/wiki/Hill\_cipher][https_en.wikipedia.org_wiki_Hill_cipher]

## C语言的Hill密码程序 **(**Hill Cipher Program in C**)** ##

#include<stdio.h>
    #include<math.h>
     
    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 < 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];
    	
    	printf("\n\nInverse Matrix is:\n");
    	for(i = 0; i < 3; i++) {
    		for(j = 0; j < 3; j++)
    			printf("%d ", b[i][j]);
    		
    		printf("\n");
    	}
    }

## C ++中的Hill密码程序 **(**Hill Cipher Program in C++**)** ##

#include<iostream>
    #include<math.h>
     
    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 < 1; j++)
    			for(k = 0; k < 3; k++)
    				decrypt[i][j] = decrypt[i][j] + b[i][k] * encrypt[k][j];
    	
    	cout<<"\nDecrypted string is: ";
    	for(i = 0; i < 3; i++)
    		cout<<(char)(fmod(decrypt[i][0], 26) + 97);
    	
    	cout<<"\n";
    }
     
    void getKeyMessage() {
    	int i, j;
    	char msg[3];
     
    	cout<<"Enter 3x3 matrix for key (It should be inversible):\n";
    	
    	for(i = 0; i < 3; i++)
    		for(j = 0; j < 3; j++) {
    			cin>>a[i][j];
    			c[i][j] = a[i][j];
    		}
    	
    	cout<<"\nEnter a 3 letter string: ";
    	cin>>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**

**输出量**

![Hill Cipher in C and C++ (Encryption and Decryption)][Hill Cipher in C and C_ _Encryption and Decryption]

Comment below if you have any queries related to above program for hill cipher in C and C++.

如果您有任何与上述程序有关C和C ++的Hill密码相关的查询，请在下面评论。

> 翻译自: [https://www.thecrazyprogrammer.com/2017/02/hill-cipher-c.html][https_www.thecrazyprogrammer.com_2017_02_hill-cipher-c.html]

[Caesar Cipher in C and C_ _Encryption _ Decryption]: https://www.thecrazyprogrammer.com/2016/11/caesar-cipher-c-c-encryption-decryption.html
[https_en.wikipedia.org_wiki_Hill_cipher]: https://en.wikipedia.org/wiki/Hill_cipher
[Hill Cipher in C and C_ _Encryption and Decryption]: /images/20221123/4d683c1e66bb472cb6a969a411dad6cd.png
[https_www.thecrazyprogrammer.com_2017_02_hill-cipher-c.html]: https://www.thecrazyprogrammer.com/2017/02/hill-cipher-c.html