Summary of usage of PHP encryption functions md5, crypt, base64_encode, etc.

php will use the encryption of the characters variable when registering, logging in or passing parameters in the URL. Let’s briefly introduce it: PHP’s own encryption function

Irreversible encryption functions are: md5(), crypt()
md5() is used to calculate MD5 hash. The syntax is: string md5(string str);
crypt() Encrypt string using UNIX’s standard encryption DES module. This is a one-way encryption function and cannot be decrypted. To compare strings, place the first two characters of the encrypted string in the salt parameter, and then compare the encrypted strings. The syntax is: string crypt(string str, string [salt]);
The reversible encryption is: base64_encode(), urlencode() and the corresponding decryption function: base64_decode(), urldecode()

base64_encode() MIME BASE64 encodes the string. This encoding method allows Chinese text or pictures to be transmitted smoothly over the Internet. The syntax is string base64_encode(string data); Its decryption function is: string base64_decode(string encoded_data); It will return to its original state
urlencode() URL-encodes the string. For example, spaces will become plus signs. The syntax is: string urlencode(string str);
Its decryption function is: string urldecode(string str); It will return to the original state

Look at the code:

Code As follows:

<?php 
define("str","墨剑"); 
echo &#39;md5 加密后的结果为：&#39;.md5(str).&#39;<br>&#39;;//md5 加密 
echo &#39;crypt加密后的结果为：&#39;.crypt(str,str).&#39;<br>&#39;;// crypt加密 
$base64encode=base64_encode(str);// base64_encode() 加密 
echo &#39;base64_encode加密后的结果为：&#39;.$base64encode.&#39;<br>&#39;; 
echo &#39;base64_decode解密后的结果为：&#39;.base64_decode($base64encode).&#39;<br>&#39;; //base64_decode()解密 
$urlencode=urlencode(str); //urlencode() 加密 
echo &#39;urlencode加密后的结果为：&#39;.$urlencode.&#39;<br>&#39;; 
echo &#39;urldecode解密后的结果为：&#39;.urldecode($urlencode).&#39;<br>&#39;;//urldecode() 解密 
?>

The output result is:
md5 The encrypted result is: ea796af15c74e90faeba49576fa7984b
crypt The encrypted result is: ink ylCzgTtYXPs
base64_encode The encrypted result is: xKu9ow==
base64_decode The result after decryption is: Mo Jian
The result after urlencode encryption is: %C4%AB%BD%A3
The result after urldecode decryption is: Mo Jian

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