How to write a simple Caesar cipher encryption program using Golang

The Caesar cipher is a simple encryption algorithm, also known as the shift cipher. Its principle is to move each letter in the plaintext by a fixed amount to obtain the ciphertext. In this article, we will learn how to write a simple Caesar cipher encryption program using Golang.

First, let us review the principles of encryption and decryption of the Caesar cipher. For a given letter, its value after being encrypted by Caesar cipher can be expressed by the following formula:

Ciphertext = (plaintext key) mod 26

In this formula, "Plaintext" represents the original letters, "key" represents the amount we want to move the letters, and "mod 26" represents mapping the letters to 26 positions in the alphabet to get the ciphertext.

Next, we will implement a simple Caesar cipher encryption program, we will input the plaintext and key as input, and then output the ciphertext.

First, we need to import the "fmt" package so that we can read user input and output results. We will also use string constants to define the order of the 26 letters so that we can select specific letters from them.

package main

import "fmt"

const alphabet = "abcdefghijklmnopqrstuvwxyz"

Next, we will define a function that accepts a string and an integer as input and returns a string. This function will implement the encryption function of Caesar cipher:

func caesarCipher(s string, k int) string {
    var result []byte

    for i := 0; i = 'a' && c = 'A' && c <p>In the above function, we first define an empty byte slice to save the encrypted result. We then use a loop to iterate through each character in the input string. If the character is a lowercase letter, we convert it to an integer, then add the key to that value, and finally use a modulus operation to map it to a position in the alphabet. Finally, we add the encrypted letters to the result. </p><p>For the case of uppercase letters, we can also take similar treatment, the difference is that we need to convert it to lowercase letters first, then map it to the position in the alphabet, and finally convert it to uppercase letter. </p><p>Finally, we will write a simple main function to read user input and print the results to the terminal. Here is the complete program: </p><pre class="brush:php;toolbar:false">package main

import (
    "fmt"
    "unicode"
)

const alphabet = "abcdefghijklmnopqrstuvwxyz"

func caesarCipher(s string, k int) string {
    var result []byte

    for i := 0; i = 'a' && c = 'A' && c <p>Now, we can run the program and test whether it was successful. The following is a screenshot of a sample input and output: </p><p><img src="/static/imghwm/default1.png" data-src="https://img.php.cn/upload/article/000/000/068/168230421494581.png?x-oss-process=image/resize,p_40" class="lazy" alt="How to write a simple Caesar cipher encryption program using Golang" title="How to write a simple Caesar cipher encryption program using Golang"></p><p> As can be seen from the above figure, our program has successfully implemented the Caesar cipher encryption function. Of course, this is just a very basic encryption method and it can be easily cracked. Therefore, in practical applications, more complex encryption algorithms need to be used to protect sensitive data and information. </p>

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